Ophthalmic information processing method and program

Abstract

To provide a new technique for specifying a change in the form of a tissue of an eye to be examined.SOLUTION: The ophthalmic information processing method includes a layer thickness specifying step, a characteristic position specifying step, and a risk determining step. In the layer thickness specifying step, the one or more processors specify a layer thickness of a predetermined layer region in a measurement site in an A scan direction based on the OCT data of the subject's eye. In the characteristic position specifying step, the one or more processors specify a characteristic position of a change amount of the layer thickness in a direction intersecting the A-scan direction based on the layer thickness specified in the layer thickness specifying step. In the risk determination step, the one or more processors determine the risk of the disease based on the amount of change in the characteristic position. In the risk determination step, the risk of the disease is determined based on risk determination information in which information indicating the risk of the disease is associated in advance with each of the plurality of change amounts.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an ophthalmologic information processing method and a program. [Background technology]

[0002] In recent years, optical coherence tomography (OCT), which uses a light beam from a laser or other source to form images that represent the surface and internal morphology of an object being measured, has been attracting attention. Unlike X-ray computed tomography (CT), OCT is non-invasive, and its applications are expected to expand particularly in the medical and biological fields. For example, in the field of ophthalmology, devices that form images of the fundus and cornea have been put to practical use. These OCT-based devices (OCT devices) can be used to observe various parts of the subject's eye, and because they can obtain high-resolution images, they are used to diagnose various ophthalmic diseases.

[0003] For wide-area observation of the fundus, screening for eye diseases, etc., there is a demand for an apparatus that can easily photograph or measure the fundus of a subject's eye over a wide field of view. For example, Patent Document 1 discloses the configuration of an ophthalmologic apparatus for acquiring wide-angle OCT data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-025255 Summary of the Invention [Problem to be solved by the invention]

[0005] The ability to acquire OCT data of a subject's eye at a wide angle allows detailed observation of changes in the tissue morphology of the subject's eye over a wide area, making it possible to easily identify various changes in tissue morphology that would be difficult to identify if it were not possible to acquire OCT data of the subject's eye at a wide angle.

[0006] Such a method for identifying changes in tissue morphology can be applied to OCT data of a subject's eye regardless of whether the imaging angle of view (measurement range) is wide or not.

[0007] The present invention has been made in view of the above circumstances, and one of its objects is to provide a new technique for identifying changes in the morphology of tissue in an eye to be examined. [Means for solving the problem]

[0008] One aspect of the embodiment is an ophthalmologic information processing method including: a layer thickness identification step in which one or more processors identify a layer thickness in the A-scan direction of a predetermined layer region at a measurement site based on OCT data of the test eye; a feature position identification step in which the one or more processors identify a feature position of a change in the layer thickness in a direction intersecting the A-scan direction based on the layer thickness identified in the layer thickness identification step; and a risk determination step in which the one or more processors determine a risk of disease based on the change in the feature position, wherein the risk determination step determines the risk of the disease based on risk determination information in which information representing the risk of the disease is previously associated with each of a plurality of change amounts. [Effects of the Invention]

[0009] According to the present invention, a new technique for identifying changes in the morphology of tissue in an eye to be examined can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of an optical system of an ophthalmologic apparatus according to an embodiment. [Figure 2] 1 is a schematic diagram illustrating an example of the configuration of an optical system of an ophthalmologic apparatus according to an embodiment. [Figure 3] FIG. 2 is a schematic diagram illustrating an example of the configuration of a processing system of an ophthalmologic apparatus according to an embodiment. [Figure 4] FIG. 2 is a schematic diagram illustrating an example of the configuration of a processing system of an ophthalmologic apparatus according to an embodiment. [Figure 5] FIG. 2 is a schematic diagram illustrating an example of the configuration of a processing system of an ophthalmologic apparatus according to an embodiment. [Figure 6] FIG. 2 is a schematic diagram illustrating an example of the configuration of a processing system of an ophthalmologic apparatus according to an embodiment. [Figure 7] 3A and 3B are schematic diagrams for explaining the operation of the ophthalmologic apparatus according to the embodiment. [Figure 8] 3A and 3B are schematic diagrams for explaining the operation of the ophthalmologic apparatus according to the embodiment. [Figure 9] 3A and 3B are schematic diagrams for explaining the operation of the ophthalmologic apparatus according to the embodiment. [Figure 10] 3A and 3B are schematic diagrams for explaining the operation of the ophthalmologic apparatus according to the embodiment. [Figure 11] FIG. 4 is a flowchart of an example of the operation of the ophthalmologic apparatus according to the embodiment. [Figure 12] FIG. 4 is a flowchart of an example of the operation of the ophthalmologic apparatus according to the embodiment. [Figure 13] FIG. 4 is a flowchart of an example of the operation of the ophthalmologic apparatus according to the embodiment. [Figure 14] FIG. 4 is a flowchart of an example of the operation of the ophthalmologic apparatus according to the embodiment. [Figure 15] FIG. 10 is a schematic diagram illustrating an example of the configuration of a processing system of an ophthalmologic apparatus according to a modified example of the embodiment. [Figure 16] FIG. 10 is a schematic diagram for explaining a process executed by an ophthalmologic apparatus according to a comparative example of the embodiment. [Figure 17] FIG. 10 is a schematic diagram illustrating an example of the configuration of a processing system of an ophthalmologic apparatus according to a modified example of the embodiment. [Figure 18] 10A and 10B are schematic diagrams for explaining the operation of an ophthalmologic apparatus according to a modified example of an embodiment. [Figure 19] 10A and 10B are schematic diagrams for explaining the operation of an ophthalmologic apparatus according to a modified example of an embodiment. [Figure 20] FIG. 10 is a flowchart of an example of the operation of an ophthalmologic apparatus according to a modified example of the embodiment. [Figure 21] 10A and 10B are schematic diagrams for explaining the operation of an ophthalmologic apparatus according to a modified example of an embodiment. [Figure 22]10A and 10B are schematic diagrams for explaining the operation of an ophthalmologic apparatus according to a modified example of an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] An ophthalmological information processing apparatus, an ophthalmological apparatus, an ophthalmological information processing method, and a program according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the embodiments may incorporate any of the techniques described in the documents cited in this specification.

[0012] Morphological changes in tissues of a subject's eye are thought to be useful for the early detection and diagnosis of diseases (ocular diseases). For example, if morphological changes in a specific tissue can be identified or detected with high accuracy, it may be possible to detect and diagnose the disease early before the morphological changes specific to the disease occur.

[0013] The ophthalmologic information processing apparatus according to the embodiment focuses on the amount of change in layer thickness in a predetermined layer region in a measurement site of the subject's eye, and can identify a characteristic position of the amount of change in layer thickness.

[0014] Examples of measurement sites include the fundus and the anterior segment. Examples of layer regions include the layer regions constituting the retina, the vitreous body, the lens, the anterior chamber, the layer regions constituting the cornea, and the tissue regions constituting the anterior segment. Examples of layer regions constituting the retina include the internal limiting membrane, nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, external limiting membrane, photoreceptor layer, retinal pigment epithelium layer, Bruch's membrane, choroid, and sclera. Examples of layer regions constituting the cornea include corneal epithelial cells, basement membrane, Bowman's membrane, stroma layer, Descemet's membrane, and endothelial cells. Examples of tissue regions constituting the anterior segment include Schlemm's canal, iris, ciliary body, and angle of the eye.

[0015] Specifically, the ophthalmologic information processing device according to the embodiment identifies a layer thickness in the A-scan direction of a predetermined layer region at a measurement site based on OCT data of the subject's eye. Based on the identified layer thickness, the ophthalmologic information processing device identifies a characteristic position of a change in layer thickness in a direction intersecting the A-scan direction (e.g., a B-scan direction).

[0016] The OCT data is acquired, for example, by splitting light from an OCT light source into measurement light and reference light, projecting the measurement light onto the subject's eye, and detecting interference light between return light of the measurement light from the subject's eye and the reference light passing through the reference light path. The OCT data may be two-dimensional OCT data or three-dimensional OCT data. In some embodiments, the ophthalmologic information processing device is configured to acquire OCT data obtained by an external OCT device. In some embodiments, the functions of the ophthalmologic information processing device are realized by an ophthalmologic device capable of acquiring OCT data.

[0017] In some embodiments, the ophthalmological information processing device performs a risk assessment of a disease based on the amount of change in layer thickness at the identified feature position, and generates a risk assessment result. Examples of the disease include central serous chorioretinopathy (hereinafter referred to as CSC), high myopia, age-related macular degeneration (AMD), glaucoma, and other choroid-related diseases.

[0018] In some embodiments, the ophthalmologic information processing device generates a layer thickness change profile that represents the change in layer thickness along a direction intersecting the A-scan (e.g., the B-scan direction), and displays the generated layer thickness change profile on a display unit. At this time, the ophthalmologic information processing device can display information indicating a position corresponding to a characteristic position in the layer thickness change profile on the display unit, or information indicating the change at the characteristic position in the layer thickness change profile on the display unit. In some embodiments, the ophthalmologic information processing device displays the layer thickness change profile and a tomographic image of the subject's eye formed based on the OCT data on the display unit, and displays information indicating a position corresponding to the characteristic position in the tomographic image on the display unit.

[0019] This makes it possible to identify (detect) morphological changes in the tissue of the subject's eye with high accuracy. As a result, even if the morphological changes specific to disease are not obvious, it becomes possible to determine the risk of disease and to continuously observe morphological changes in detail as areas that require future attention, enabling early detection and early treatment of disease.

[0020] An ophthalmologic information processing method according to an embodiment includes one or more steps executed by the ophthalmologic information processing device. A program according to an embodiment causes a computer (processor) to execute each step of the ophthalmologic information processing method according to an embodiment. A recording medium according to an embodiment is a non-transitory recording medium (storage medium) on which the program according to an embodiment is recorded.

[0021] In this specification, a processor includes circuits such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), or a field programmable gate array (FPGA)). The processor realizes the functions of the embodiments by, for example, reading and executing a program stored in a memory circuit or a storage device. The memory circuit or storage device may be included in the processor. Alternatively, the memory circuit or storage device may be provided external to the processor.

[0022] The following mainly describes cases where the risk of CSC is determined from the amount of change in choroidal thickness and where it is easy to identify the characteristic position of the amount of change in choroidal thickness, but the configuration of the embodiment is not limited to this. CSC is a disease in which serous retinal detachment occurs in the macula, causing symptoms such as decreased vision and central darkening.

[0023] The following embodiment is also applicable to the amount of change in thickness of layer regions other than the choroid, and to eye diseases other than CSC.

[0024] In the following embodiments, an ophthalmic apparatus including the functions of an ophthalmic information processing apparatus according to an embodiment will be described as an example. The ophthalmic apparatus according to the embodiment includes an ophthalmic imaging apparatus. The ophthalmic imaging apparatus included in the ophthalmic apparatus according to some embodiments is, for example, one or more of a fundus camera, a scanning optical ophthalmoscope, a slit lamp ophthalmoscope, a surgical microscope, etc. The ophthalmic apparatus according to some embodiments includes, in addition to the ophthalmic imaging apparatus, one or more of an ophthalmic measurement apparatus and an ophthalmic treatment apparatus. The ophthalmic measurement apparatus included in the ophthalmic apparatus according to some embodiments is, for example, one or more of an eye refraction examination apparatus, a tonometer, a specular microscope, a wavefront analyzer, a perimeter, a microperimeter, etc. The ophthalmic treatment apparatus included in the ophthalmic apparatus according to some embodiments is, for example, one or more of a laser treatment apparatus, a surgical apparatus, a surgical microscope, etc.

[0025] In the following embodiments, the ophthalmologic apparatus includes an optical coherence tomography (OCT) scanner and a fundus camera. While the swept-source OCT scanner is used, the type of OCT is not limited thereto, and other types of OCT (such as spectral domain OCT, time domain OCT, and amphas OCT) may also be used.

[0026] Hereinafter, the x direction is defined as the direction perpendicular to the optical axis direction of the objective lens (left-right direction), the y direction is defined as the direction perpendicular to the optical axis direction of the objective lens (up-down direction), and the z direction is defined as the direction of the optical axis of the objective lens.

[0027] <Configuration> [Optical system] As shown in FIG. 1, the ophthalmic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic and control unit 200. The fundus camera unit 2 is provided with an optical system and mechanisms for acquiring a front image of the subject's eye E. The OCT unit 100 is provided with a portion of the optical system and mechanisms for performing OCT. Other portions of the optical system and mechanisms for performing OCT are provided in the fundus camera unit 2. The arithmetic and control unit 200 includes one or more processors that perform various calculations and controls. In addition to these, the ophthalmic apparatus 1 may be provided with any other elements or units, such as members for supporting the subject's face (such as a chin rest or forehead rest) and a lens unit for switching the target region for OCT (for example, an attachment for anterior segment OCT). Furthermore, the ophthalmic apparatus 1 includes a pair of anterior segment cameras 5A and 5B.

[0028] In some embodiments, the ophthalmic apparatus 1 includes a display device 3. The display device 3 displays processing results (e.g., OCT images, etc.) by the arithmetic control unit 200, images obtained by the fundus camera unit 2, operation guidance information for operating the ophthalmic apparatus 1, etc.

[0029] [Fundus camera unit 2] The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef of the subject's eye E. The acquired image of the fundus Ef (called a fundus image, fundus photograph, etc.) is a front image such as an observed image or a photographed image. The observed image is obtained by video shooting using near-infrared light. The photographed image is a still image using flash light or a spectral image (spectral fundus image, spectral anterior segment image). Furthermore, the fundus camera unit 2 can photograph the anterior segment Ea of the subject's eye E to acquire a front image (anterior segment image).

[0030] The fundus camera unit 2 includes an illumination optical system 10 and an imaging optical system 30. The illumination optical system 10 irradiates illumination light onto the subject's eye E. The imaging optical system 30 detects return light of the illumination light from the subject's eye E. The measurement light from the OCT unit 100 is guided to the subject's eye E through an optical path within the fundus camera unit 2, and the return light is guided to the OCT unit 100 through the same optical path.

[0031] Light (observation illumination light) output from an observation light source 11 of an illumination optical system 10 is reflected by a reflecting mirror 12 having a curved reflecting surface, passes through a condenser lens 13, and passes through a visible light cut filter 14 to become near-infrared light. The observation illumination light is then focused near an imaging light source 15, reflected by a mirror 16, and passes through relay lenses 17 and 18, an aperture 19, and a relay lens 20. The observation illumination light is then reflected by the peripheral portion (the area surrounding the hole) of a perforated mirror 21, passes through a dichroic mirror 46, and is refracted by an objective lens 22 to illuminate the subject's eye E (fundus Ef or anterior segment Ea). Return light of the observation illumination light from the subject's eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through a hole formed in the central region of the perforated mirror 21, passes through a photographing focusing lens 31, and is reflected by a mirror 32. Furthermore, this returned light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the image sensor 35 by the condenser lens 34. The image sensor 35 detects the returned light at a predetermined frame rate. The focus of the photographing optical system 30 is adjusted to match the fundus Ef or the anterior segment Ea.

[0032] Light (photography illumination light) output from the photography light source 15 is irradiated onto the fundus oculi Ef through the same path as the observation illumination light. Return light of the photography illumination light from the subject's eye E is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by a mirror 36, and is focused on the light receiving surface of an image sensor 38 by a condenser lens 37.

[0033] The display device 3 displays an image (observation image) based on the fundus reflected light detected by the image sensor 35. When the focus of the photographing optical system 30 is adjusted to the anterior segment, an observation image of the anterior segment of the subject's eye E is displayed. The display device 3 also displays an image (photographed image, spectral fundus image) based on the fundus reflected light detected by the image sensor 38. The display device 3 that displays the observation image and the display device 3 that displays the photographed image may be the same or different. When the subject's eye E is illuminated with infrared light and similar photographing is performed, an infrared photographed image is displayed.

[0034] A fixation target and a visual target for visual acuity testing are displayed on an LCD (Liquid Crystal Display) 39. A portion of the light beam output from the LCD 39 is reflected by a half mirror 33A, reflected by a mirror 32, passes through a photographing focusing lens 31, and passes through a hole in the aperture mirror 21. The light beam that has passed through the hole in the aperture mirror 21 passes through a dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef.

[0035] The fixation position of the subject's eye E can be changed by changing the display position of the fixation target on the screen of the LCD 39. Examples of fixation positions include a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, a fixation position for acquiring an image centered on the fundus between the macula and the optic disc, and a fixation position for acquiring an image of a region far removed from the macula (periphery of the fundus). The ophthalmologic apparatus 1 according to some embodiments includes a GUI (Graphical User Interface) or the like for specifying at least one of such fixation positions. The ophthalmologic apparatus 1 according to some embodiments includes a GUI or the like for manually moving the fixation position (display position of the fixation target).

[0036] The configuration for presenting a movable fixation target to the subject's eye E is not limited to a display device such as an LCD. For example, a movable fixation target can be generated by selectively illuminating a plurality of light sources in a light source array (such as a light-emitting diode (LED) array). Also, a movable fixation target can be generated by one or more movable light sources.

[0037] The focusing optical system 60 generates a split index used for focus adjustment of the subject's eye E. The focusing optical system 60 moves along the optical path (illumination optical path) of the illumination optical system 10 in conjunction with movement of the photographing focusing lens 31 along the optical path (photographing optical path) of the photographing optical system 30. The reflecting rod 67 is insertable into and removable from the illumination optical path. When performing focus adjustment, the reflective surface of the reflecting rod 67 is tilted and positioned in the illumination optical path. The focusing light output from the LED 61 passes through the relay lens 62, is split into two beams by the split index plate 63, passes through the two-hole diaphragm 64, is reflected by the mirror 65, and is once imaged and reflected on the reflective surface of the reflecting rod 67 by the condenser lens 66. The focusing light further passes through the relay lens 20, is reflected by the aperture mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fundus reflection light of the focusing light is guided to the image sensor 35 via the same path as the return light of the observation illumination light. Manual focusing and autofocusing can be performed based on the received light image (split target image).

[0038] The dichroic mirror 46 combines the optical path for fundus imaging and the optical path for OCT. The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus imaging. The OCT optical path (optical path of measurement light) is provided with a collimator lens unit 40, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, and a relay lens 45 in this order from the OCT unit 100 side to the dichroic mirror 46 side.

[0039] The optical path length changing unit 41 is movable in the direction of the arrow shown in Figure 1 to change the length of the OCT optical path. This change in optical path length is used for correcting the optical path length according to the axial length of the eye, adjusting the interference state, etc. The optical path length changing unit 41 includes a corner cube and a mechanism for moving it.

[0040] The optical scanner 42 is disposed at a position optically conjugate with the pupil of the subject's eye E. The optical scanner 42 deflects the measurement light LS passing through the OCT optical path. The optical scanner 42 is, for example, a galvano scanner capable of two-dimensional scanning.

[0041] The OCT focusing lens 43 is moved along the optical path of the measurement light LS to adjust the focus of the OCT optical system. The movement of the imaging focusing lens 31, the movement of the focus optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

[0042] [Anterior Eye Cameras 5A and 5B] The anterior eye cameras 5A and 5B are used to determine the relative position between the optical system of the ophthalmic apparatus 1 and the subject's eye E, similar to the method described in, for example, Japanese Patent Application Laid-Open No. 2013-248376. The anterior eye cameras 5A and 5B are provided on the surface of a housing (such as the fundus camera unit 2) that houses the optical system, facing the subject's eye E. The ophthalmic apparatus 1 determines the three-dimensional relative position between the optical system and the subject's eye E by analyzing two anterior eye images acquired substantially simultaneously from different directions by the anterior eye cameras 5A and 5B. The analysis of the two anterior eye images may be similar to the analysis disclosed in Japanese Patent Application Laid-Open No. 2013-248376. The number of anterior eye cameras may be any number equal to or greater than two.

[0043] In this example, the position of the subject's eye E (i.e., the relative position between the subject's eye E and the optical system) is determined using two or more anterior segment cameras, but the method for determining the position of the subject's eye E is not limited to this. For example, the position of the subject's eye E can be determined by analyzing a front image of the subject's eye E (e.g., an observation image of the anterior segment Ea). Alternatively, a means for projecting an index onto the cornea of ​​the subject's eye E can be provided, and the position of the subject's eye E can be determined based on the projection position of this index (i.e., the detection state of the corneal reflected light beam of this index).

[0044] [OCT Unit 100] As illustrated in Fig. 2, the OCT unit 100 is provided with an optical system for performing swept-source OCT. This optical system includes an interference optical system. This interference optical system has the following functions: splitting light from a wavelength-tunable light source (swept-wavelength light source) into measurement light and reference light; generating interference light by superimposing return light of the measurement light from the subject's eye E on the reference light that has passed through the reference light path; and detecting this interference light. The detection result (detection signal) of the interference light obtained by the interference optical system is a signal indicating the spectrum of the interference light, and is sent to the arithmetic and control unit 200.

[0045] The light source unit 101 includes, for example, a near-infrared wavelength-tunable laser that changes the wavelength of the emitted light at high speed. The light L0 output from the light source unit 101 is guided by an optical fiber 102 to a polarization controller 103, where its polarization state is adjusted. The light L0, whose polarization state has been adjusted, is guided by an optical fiber 104 to a fiber coupler 105, where it is split into a measurement light LS and a reference light LR.

[0046] The reference light LR is guided by an optical fiber 110 to a collimator 111, where it is converted into a parallel beam, and then guided to a corner cube 114 via an optical path length correction member 112 and a dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with the optical path length of the measurement light LS. The dispersion compensation member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS. The corner cube 114 is movable in the incident direction of the reference light LR, thereby changing the optical path length of the reference light LR.

[0047] The reference light LR that has passed through the corner cube 114 passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel beam into a convergent beam by the collimator 116, and enters the optical fiber 117. The reference light LR that has entered the optical fiber 117 is guided to the polarization controller 118 where its polarization state is adjusted, is guided by the optical fiber 119 to the attenuator 120 where the light amount is adjusted, and is guided by the optical fiber 121 to the fiber coupler 122.

[0048] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and converted into a parallel beam by the collimator lens unit 40, and passes through the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, the mirror 44, and the relay lens 45. After passing through the relay lens 45, the measurement light LS is reflected by the dichroic mirror 46, refracted by the objective lens 22, and enters the subject's eye E. The measurement light LS is scattered and reflected at various depth positions in the subject's eye E. The return light of the measurement light LS from the subject's eye E travels the same path as the outward path in the reverse direction, guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128. The incident end of the optical fiber 127, into which the measurement light LS is incident, is positioned approximately conjugate with the fundus Ef of the subject's eye E.

[0049] The fiber coupler 122 generates interference light by combining (causing interference between) the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121. The fiber coupler 122 splits the interference light at a predetermined splitting ratio (for example, 1:1) to generate a pair of interference lights LC. The pair of interference lights LC are guided to a detector 125 via optical fibers 123 and 124, respectively.

[0050] The detector 125 is, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that respectively detect a pair of interference lights LC, and outputs the difference between the pair of detection results obtained by these photodetectors. The detector 125 sends this output (detection signal) to a DAQ (Data Acquisition System) 130.

[0051] The DAQ 130 is supplied with a clock KC from the light source unit 101. The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength-tunable light source. For example, the light source unit 101 optically delays one of two branched lights obtained by branching light L0 of each output wavelength, and then generates the clock KC based on the result of detecting the combined light. The DAQ 130 samples the detection signal input from the detector 125 based on the clock KC. The DAQ 130 sends the sampling result of the detection signal from the detector 125 to the arithmetic and control unit 200.

[0052] In this example, both an optical path length changer 41 for changing the length of the optical path (measurement optical path, measurement arm) of the measurement light LS and a corner cube 114 for changing the length of the optical path (reference optical path, reference arm) of the reference light LR are provided. However, only one of the optical path length changer 41 and the corner cube 114 may be provided. It is also possible to change the difference between the measurement optical path length and the reference optical path length using optical members other than these.

[0053] [Processing system] 3 to 6 show examples of the configuration of the processing system of the ophthalmic apparatus 1. Some of the components included in the ophthalmic apparatus 1 are omitted in FIGS. 3 to 6. In FIG. 3, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate. The control unit 210, image forming unit 220, and data processing unit 230 are provided in, for example, an arithmetic control unit 200.

[0054] <Control unit 210> The control unit 210 executes various controls and includes a main control unit 211 and a storage unit 212.

[0055] <Main control unit 211> The main controller 211 includes a processor (for example, a control processor) and controls each part (including each element shown in FIGS. 1 to 6) of the ophthalmologic apparatus 1. For example, the main controller 211 controls each part of the optical system of the fundus camera unit 2 shown in FIGS. 1 and 2, each part of the optical system of the OCT unit 100, the anterior eye cameras 5A and 5B, the moving mechanism 150 that moves the above-mentioned optical systems, the image forming unit 220, the data processing unit 230, and the user interface (UI) 240.

[0056] The control of the fundus camera unit 2 includes control of the focusing drivers 31A and 43A, control of the image sensors 35 and 38, control of the LCD 39, control of the optical path length changer 41, and control of the optical scanner 42.

[0057] Control over the focus driver 31A includes control to move the photographing focus lens 31 in the optical axis direction. Control over the focus driver 43A includes control to move the OCT focus lens 43 in the optical axis direction.

[0058] Control of the image sensors 35 and 38 includes control of the light receiving sensitivity of the imaging elements, control of the frame rate (light receiving timing, exposure time), control of the light receiving area (position, size, dimension), and control of reading out the light receiving results from the imaging elements.

[0059] Control of the LCD 39 includes control of the fixation position. For example, the main control unit 211 displays a fixation target at a position on the screen of the LCD 39 that corresponds to a manually or automatically set fixation position. The main control unit 211 can also change (continuously or stepwise) the display position of the fixation target displayed on the LCD 39. This makes it possible to move the fixation target (i.e., change the fixation position). The display position and movement manner of the fixation target are set manually or automatically. Manual setting is performed using, for example, a GUI. Automatic setting is performed by, for example, the data processing unit 230.

[0060] The control over the optical path length changing unit 41 includes control to change the optical path length of the measurement light LS. The main control unit 211 controls a drive unit that drives the corner cube of the optical path length changing unit 41 to move the optical path length changing unit 41 along the optical path of the measurement light LS and change the optical path length of the measurement light LS.

[0061] The control of the optical scanner 42 includes control of the scan mode, scan range (scan start position, scan end position), scan speed, etc. The main controller 211 controls the optical scanner 42, thereby enabling an OCT scan to be performed with the measurement light LS on a desired region in the measurement region (image capture region).

[0062] The main control unit 211 also controls the observation light source 11, the imaging light source 15, the focus optical system 60, and the like.

[0063] The control over the OCT unit 100 includes control over the light source unit 101, control over the reference driver 114A, control over the detector 125, and control over the DAQ .

[0064] Control of the light source unit 101 includes control of turning the light source on and off, control of the amount of light emitted from the light source, control of the wavelength sweep range, control of the wavelength sweep speed, and control of the emission timing of light of each wavelength component.

[0065] The control over the reference driver 114A includes control to change the optical path length of the reference light LR. The main controller 211 controls the reference driver 114A to move the corner cube 114 along the optical path of the reference light LR, thereby changing the optical path length of the reference light LR.

[0066] Control of the detector 125 includes control of the light receiving sensitivity of the detection elements, control of the frame rate (light receiving timing), control of the light receiving area (position, size, dimension), and control of reading out the light receiving results of the detection elements.

[0067] The control over the DAQ 130 includes control of capturing (capturing timing, sampling timing) the detection results of the interference light obtained by the detector 125, and control of reading out the interference signal corresponding to the detection results of the captured interference light.

[0068] Control of the anterior eye cameras 5A and 5B includes control of the light receiving sensitivity of each camera, control of the frame rate (light receiving timing), and synchronization control of the anterior eye cameras 5A and 5B.

[0069] The movement mechanism 150 moves at least the fundus camera unit 2 (optical system) three-dimensionally, for example. In a typical example, the movement mechanism 150 includes at least a mechanism for moving the fundus camera unit 2 in the x direction (left-right direction), a mechanism for moving it in the y direction (up-down direction), and a mechanism for moving it in the z direction (depth direction, front-back direction). The mechanism for movement in the x direction includes, for example, an x-stage movable in the x direction and an x-movement mechanism for moving the x-stage. The mechanism for movement in the y direction includes, for example, a y-stage movable in the y direction and a y-movement mechanism for moving the y-stage. The mechanism for movement in the z direction includes, for example, a z-stage movable in the z direction and a z-movement mechanism for moving the z-stage. Each movement mechanism includes a pulse motor as an actuator and operates under the control of the main controller 211.

[0070] Control of the moving mechanism 150 is used for alignment and tracking. Tracking is the act of moving the device optical system in accordance with the eye movement of the subject's eye E. When tracking is performed, alignment and focus adjustment are performed beforehand. Tracking is a function of maintaining a suitable positional relationship where alignment and focus are achieved by making the position of the device optical system follow the eye movement. In some embodiments, the moving mechanism 150 is configured to be controlled to change the optical path length of the reference light (and therefore the optical path length difference between the optical path of the measurement light and the optical path of the reference light).

[0071] In the case of manual alignment, the user operates the user interface 240 to move the optical system relative to the eye E so that the displacement of the eye E relative to the optical system is canceled. For example, the main control unit 211 controls the movement mechanism 150 by outputting a control signal corresponding to the operation content on the user interface 240 to the movement mechanism 150, thereby moving the optical system relative to the eye E.

[0072] In the case of auto-alignment, the main controller 211 controls the moving mechanism 150 to move the optical system relative to the subject's eye E so that displacement of the subject's eye E relative to the optical system is canceled. Specifically, as described in Japanese Patent Application Laid-Open No. 2013-248376, calculation processing is performed using trigonometry based on the positional relationship between the pair of anterior eye cameras 5A and 5B and the subject's eye E, and the main controller 211 controls the moving mechanism 150 so that the positional relationship of the subject's eye E with respect to the optical system becomes a predetermined positional relationship. In some embodiments, the main controller 211 controls the moving mechanism 150 by outputting a control signal to the moving mechanism 150 so that the optical axis of the optical system approximately coincides with the axis of the subject's eye E and the distance of the optical system from the subject's eye E is a predetermined working distance, thereby moving the optical system relative to the subject's eye E. Here, the working distance is a predetermined value also called the working distance of the objective lens 22, and corresponds to the distance between the subject's eye E and the optical system during measurement (photography) using the optical system.

[0073] The main controller 211 also includes a display controller 211A. The display controller 211A can display various types of information on the display unit 240A. For example, the display controller 211A causes the display unit 240A to display a fundus image or an anterior segment image acquired using the fundus camera unit 2, a tomographic image or a front image (OCT image) acquired using the OCT unit 100, or a data processing result (analysis processing result) acquired by the data processor 230 (described later). Examples of the data processing result include a layer thickness change amount profile indicating the amount of change in the layer thickness of the choroid (described later), information indicating a characteristic position in the layer thickness change amount profile, and information indicating the amount of change in layer thickness at a characteristic position in the layer thickness change amount profile. In some embodiments, the display controller 211A causes the display unit 240A to display the data processing result in association with at least one of the fundus image (or an anterior segment image) and the OCT image.

[0074] <Storage section 212> The storage unit 212 stores various types of data. The functions of the storage unit 212 are realized by a storage device such as a memory or a storage device. Examples of data stored in the storage unit 212 include image data of fundus images, image data of anterior segment images, OCT data (including OCT images), and information about the subject's eye. The information about the subject's eye includes information about the subject, such as a patient ID and name, identification information for the left eye / right eye, and electronic medical record information. The storage unit 212 stores programs for executing various processors (control processor, image formation processor, data processing processor).

[0075] The storage unit 212 also stores risk assessment information 212A. The risk assessment information 212A is information for assessing the risk of CSC (disease). Examples of the risk of CSC include whether or not there is a CSC (disease) (presence or absence of disease) and the probability of CSC (possibility of disease). An example of the risk assessment information 212A is standard data (reference data, statistical data) in which risk information on CSC is previously associated with the amount of change at a characteristic position in a profile of change in choroidal layer thickness for a plurality of test eyes.

[0076] <Image forming unit 220> The image forming unit 220 includes a processor (e.g., an image forming processor) and forms an OCT image (image data) of the subject's eye E based on the output (sampling results of the detection signals) from the DAQ 130. For example, similar to conventional swept-source OCT, the image forming unit 220 performs signal processing on the spectral distribution based on the sampling results for each A-line to form a reflection intensity profile for each A-line, and then images these A-line profiles and arranges them along the scan line. The signal processing includes noise removal (noise reduction), filtering, FFT (Fast Fourier Transform), etc. When performing other types of OCT, the image forming unit 220 performs known processing appropriate for the type.

[0077] Data Processing Unit 230 Data processing unit 230 includes a processor (for example, a data processor) and performs image processing and analysis processing on the image formed by image forming unit 220. At least two of the processor included in main control unit 211, the processor included in data processing unit 230, and the processor included in image forming unit 220 may be configured by a single processor.

[0078] The data processing unit 230 performs known image processing, such as interpolation processing that interpolates pixels between tomographic images, to form image data of a three-dimensional image of the fundus oculi Ef or the anterior segment Ea. Note that image data of a three-dimensional image refers to image data in which pixel positions are defined by a three-dimensional coordinate system. Image data of a three-dimensional image includes image data consisting of three-dimensionally arranged voxels. This image data is called volume data or voxel data. When displaying an image based on the volume data, the data processing unit 230 performs rendering processing (volume rendering, MIP (Maximum Intensity Projection), etc.) on the volume data to form image data of a pseudo three-dimensional image as viewed from a specific line of sight. This pseudo three-dimensional image is displayed on a display device, such as the display unit 240A.

[0079] It is also possible to form stack data of multiple tomographic images as image data of a three-dimensional image. Stack data is image data obtained by arranging multiple tomographic images obtained along multiple scan lines in a three-dimensional manner based on the positional relationship of the scan lines. In other words, stack data is image data obtained by expressing multiple tomographic images that were originally defined using separate two-dimensional coordinate systems using a single three-dimensional coordinate system (i.e., embedding them in a single three-dimensional space).

[0080] In some embodiments, the data processing unit 230 generates a B-scan image by arranging A-scan images in the B-scan direction. In some embodiments, the data processing unit 230 can generate a B-mode image (B-scan image) (longitudinal or axial image) of an arbitrary cross section, a C-mode image (C-scan image) (transverse or horizontal image) of an arbitrary cross section, a projection image, a shadowgram, or the like, by performing various rendering operations on the acquired three-dimensional data set (volume data, stack data, etc.). An image of an arbitrary cross section, such as a B-scan image or a C-scan image, is generated by selecting pixels (voxels) on a specified cross section from the three-dimensional data set. A projection image is generated by projecting the three-dimensional data set in a predetermined direction (z direction, depth direction, axial direction). A shadowgram is generated by projecting a portion of the three-dimensional data set (e.g., partial data corresponding to a specific layer) in a predetermined direction. By changing the depth range in the layer direction to be integrated, two or more different shadowgrams can be generated. Images viewed from the front side of the subject's eye, such as C-scan images, projection images, and shadowgrams, are called en-face images.

[0081] The data processing unit 230 can construct B-scan images and front images (vessel-enhanced images, angiograms) in which retinal blood vessels and choroidal blood vessels are emphasized based on data collected in time series by OCT (for example, B-scan image data). For example, time-series OCT data can be collected by repeatedly scanning approximately the same region of the subject's eye E.

[0082] In some embodiments, the data processor 230 compares time-series B-scan images obtained by B-scanning approximately the same region, and constructs an enhanced image in which the changed region is emphasized by converting pixel values ​​of the changed region in signal intensity into pixel values ​​corresponding to the changed region. Furthermore, the data processor 230 extracts information of a predetermined thickness of a desired region from the constructed multiple enhanced images, and constructs the information as an en-face image to form an OCTA (angiography) image.

[0083] 4, the data processing unit 230 includes an alignment processing unit 250 and a risk assessment processing unit 260. The alignment processing unit 250 executes processing for aligning the optical system of the ophthalmologic apparatus 1 with respect to the subject's eye E. The risk assessment processing unit 260 executes processing for assessing the risk of CSC.

[0084] <Alignment Processing Unit 250> 5, the alignment processing unit 250 includes a characteristic site identification unit 251 and a three-dimensional position calculation unit 252. The alignment processing unit 250 determines the three-dimensional position of the subject's eye E based on the positions of the anterior eye cameras 5A and 5B and the positions of the characteristic sites. The main control unit 211 controls the movement mechanism 150 based on the determined three-dimensional position to move the optical system relative to the subject's eye E, thereby aligning the optical system with the subject's eye E.

[0085] <Characteristic part identification unit 251> The characteristic portion identifying unit 251 analyzes each of the captured images obtained by the anterior eye cameras 5A and 5B to identify a position in the captured image corresponding to a characteristic portion of the anterior eye Ea (referred to as a characteristic portion). As the characteristic portion, for example, the pupil region of the subject's eye E, the pupil center position of the subject's eye E, the pupil centroid position, the corneal center position, the corneal apex position, the subject's eye center position, or the iris is used. Below, a specific example of processing for identifying the pupil center position of the subject's eye E will be described.

[0086] First, the characteristic part identification unit 251 identifies an image area (pupil area) corresponding to the pupil of the subject's eye E based on the distribution of pixel values ​​(such as brightness values) of the captured image. Since the pupil is generally depicted with lower brightness than other parts, the pupil area can be identified by searching for an image area with low brightness. At this time, the pupil area may be identified taking into consideration the shape of the pupil. In other words, the characteristic part identification unit 251 can be configured to identify the pupil area by searching for an image area with a substantially circular shape and low brightness.

[0087] Next, characteristic portion identification unit 251 identifies the center position of the identified pupil region. Because the pupil is approximately circular as described above, the outline of the pupil region is identified, and the center position of this outline (an approximate circle or ellipse) is identified and can be used as the pupil center position. Alternatively, the center of gravity of the pupil region may be found, and this center position may be identified as the pupil center position.

[0088] Even when identifying a feature position corresponding to another feature portion, it is possible to identify the feature position based on the distribution of pixel values ​​of the captured image in the same manner as described above.

[0089] The characteristic part specifying unit 251 can sequentially specify characteristic positions corresponding to characteristic parts in the photographed images sequentially obtained by the anterior eye cameras 5A and 5B. Furthermore, the characteristic part specifying unit 251 may specify characteristic positions every arbitrary number of frames greater than or equal to one in the photographed images sequentially obtained by the anterior eye cameras 5A and 5B.

[0090] <3D position calculation unit 252> The three-dimensional position calculation unit 252 specifies the three-dimensional position of the characteristic site as the three-dimensional position of the subject's eye E based on the positions of the anterior-segment cameras 5A and 5B and the characteristic position corresponding to the characteristic site specified by the characteristic site specification unit 251. As disclosed in Japanese Patent Application Laid-Open No. 2013-248376, the three-dimensional position calculation unit 252 calculates the three-dimensional position of the subject's eye E by applying known trigonometry to the positions (known) of the two anterior-segment cameras 5A and 5B and the positions corresponding to the characteristic sites in the two captured images. The three-dimensional position calculated by the three-dimensional position calculation unit 252 is sent to the main controller 211. The main controller 211 controls the movement mechanism 150 based on the three-dimensional position so that the positions in the x and y directions of the optical axis of the optical system coincide with the positions in the x and y directions of the three-dimensional position and so that the distance in the z direction is a predetermined working distance.

[0091] <Risk assessment processing unit 260> 6, the risk assessment processing unit 260 includes a layer region identifying unit 261, a layer thickness identifying unit 262, a feature position identifying unit 263, a layer thickness change amount profile generating unit 264, and a risk assessment unit 265. The feature position identifying unit 263 includes a moving average processing unit 2631 and a maximum value identifying unit 2632.

[0092] <Layer area identification unit 261> The layer region specifying unit 261 specifies a predetermined layer region based on OCT data obtained by performing OCT on the subject's eye E. Examples of layer regions include the inner limiting membrane, nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, external limiting membrane, photoreceptor layer, retinal pigment epithelium layer, Bruch's membrane, choroid, and sclera.

[0093] In some embodiments, the layer region identifying unit 261 identifies a predetermined layer region based on the intensity of an interference signal obtained by detecting the interference light. For example, the layer region identifying unit 261 identifies a position showing an extreme value (maximum value) of the intensity of the interference signal as a position corresponding to the boundary position of the layer region, and identifies the layer region based on the position showing the maximum value of the intensity of the interference signal.

[0094] In some embodiments, the layer region identifying unit 261 identifies a predetermined layer region based on a tomographic image of the fundus oculi Ef formed by the image forming unit 220. For example, the layer region identifying unit 261 identifies a candidate boundary position of a layer region in the fundus oculi Ef from the intensity difference (difference in brightness value, difference in pixel value) between two or more adjacent pixels in the tomographic image. At this time, the layer region identifying unit 261 identifies a first candidate boundary position obtained by binarizing the intensity difference using a first threshold value and a second candidate boundary position obtained by binarizing the intensity difference using a second threshold value higher than the first threshold value. The first candidate boundary position is a candidate boundary position identified in a state containing a large amount of noise components. The second candidate boundary position is a candidate boundary position where there is a possibility that a portion necessary as the boundary position of the layer region is missing. Note that the layer region identifying unit 261 can identify the first candidate boundary position and the second candidate boundary position after removing portions unrelated to the boundary based on an intensity gradient (brightness gradient) from the multiple candidate boundary positions of the layer region identified from the intensity difference. The layer region identifying unit 261 identifies one of the first boundary candidate positions that is connected to the second boundary candidate position as a boundary position of the layer region. The layer region identifying unit 261 identifies the area between the two identified boundary positions as a layer region.

[0095] In this embodiment, the layer region specifying unit 261 specifies a boundary position corresponding to Bruch's membrane and a boundary position corresponding to the choroid / sclera interface (CSI), and specifies the choroid from the two specified boundary positions.

[0096] <Layer thickness specification section 262> The layer thickness specifying unit 262 specifies the layer thickness in the A-scan direction of the layer region specified by the layer region specifying unit 261. For example, the layer thickness specifying unit 262 specifies the distance in the A-scan direction between the two specified boundary positions as the layer thickness of the layer region between the two boundary positions.

[0097] In this embodiment, the layer thickness specifying unit 262 specifies the distance in the A-scan direction between the boundary position corresponding to Bruch's membrane and the boundary position corresponding to CSI as the layer thickness (film thickness) of the choroid.

[0098] The layer thickness specifying unit 262 can sequentially specify the layer thickness of the choroid at the measurement positions (positions of A-lines) of the A-scans arranged in the B-scan direction. The measurement positions of the A-scans are specified from the scan angles of the A-lines (scan angles of the A-scans centered on the scan center position of the OCT scan) obtained by dividing the imaging angle of view specific to the ophthalmologic apparatus 1 by the number of pixels in the B-scan direction in the tomographic image. The layer thickness specifying unit 262 can sequentially calculate the difference in layer thickness between adjacent A-lines in the B-scan direction for each scan angle of the A-line.

[0099] <Feature position identification unit 263> The characteristic position specifying unit 263 specifies the characteristic position of the amount of change in the choroidal layer thickness in the B scan direction intersecting the A scan direction.

[0100] As described above, the layer thickness specifying unit 262 specifies the layer thickness for each scan angle of the A-line. Therefore, the characteristic position identification unit 263 can identify the characteristic position of the change in layer thickness based on the difference in layer thickness between adjacent A lines in the B scan direction and the scan angle for each A line centered on the scan center position of the OCT scan.

[0101] Examples of characteristic positions include a position indicating a maximum value of the amount of change, a position indicating a minimum value of the amount of change, one or more positions indicating a local maximum value of the amount of change, one or more positions indicating a local minimum value of the amount of change, one or more positions where the amount of change or an extreme value of the amount of change is equal to or greater than a threshold, and one or more positions where the amount of change or an extreme value of the amount of change is equal to or less than a threshold. The one or more positions indicating a local maximum value of the amount of change may be multiple upper positions when the local maximum values ​​are sorted in descending order. The one or more positions indicating a local minimum value of the amount of change may be multiple lower positions when the local minimum values ​​are sorted in descending order.

[0102] <Moving average processing unit 2631> The moving average processing unit 2631 smoothes the layer thicknesses (layer thickness data) of multiple A lines adjacent in the B scan direction (the direction intersecting the A scan direction) in the B scan direction. This smoothes the layer thickness profile data, which is stepped in pixel units, and makes it possible to calculate extrema, described below, with good reproducibility from the layer thickness profile data smoothed in the B scan direction (i.e., it is possible to identify feature positions with high reproducibility).

[0103] Specifically, the moving average processor 2631 generates a smoothed layer thickness profile by sequentially calculating moving averages of layer thicknesses of a plurality of A-lines in a predetermined scan angle range adjacent to the B-scan direction. For example, the moving average processor 2631 calculates an average value of N (N is an integer of 2 or more) pieces of layer thickness data adjacent to the B-scan direction in a scan angle range of 0 to 10 degrees, calculates an average value of N pieces of layer thickness data adjacent to the B-scan direction in a scan angle range of 1 to 11 degrees, ..., calculates an average value of N pieces of layer thickness data adjacent to the B-scan direction in a range of (Sr+1) to (Sr+10) degrees, thereby generating a layer thickness profile.

[0104] The smoothing of the layer thickness data according to the embodiment is not limited to the moving average process, and for example, the layer thickness data may be smoothed in the B-scan direction by spline interpolation or polynomial approximation.

[0105] <Maximum value specification unit 2632> The maximum value identifying unit 2632 identifies the position showing the maximum value of the amount of change in the choroidal layer thickness as a characteristic position showing the choroidal change maximum value. In some embodiments, the maximum value identifying unit 2632 sequentially analyzes the amount of change in the layer thickness of each A-line in the B-scan direction, thereby identifying the position of the A-line showing the maximum amount of change in the layer thickness as a characteristic position.

[0106] In some embodiments, the maximum value identification unit 2632 identifies a maximum value of the amount of change for each range of a plurality of A-lines arranged in the B-scan direction, and identifies the position of the A-line that shows the maximum amount of change from the identified plurality of maximum values ​​as the characteristic position.

[0107] In some embodiments, the maximum value identifyr 2632 identifies the maximum value of the amount of change in layer thickness in the B-scan direction within a predetermined A-line range. The predetermined A-line range may be a predetermined range, a range identified by the data processing unit 230, or a range specified using the operation unit 240B described below. An example of a range identified by the data processing unit 230 is a range determined based on a characteristic site (e.g., the macula) of the subject's eye E (e.g., a range including the characteristic site, or a range a predetermined distance away from the characteristic site).

[0108] <Layer Thickness Variation Profile Generator 264> The layer thickness variation amount profile generating unit 264 generates a layer thickness variation amount profile that indicates the amount of variation in layer thickness along the B scan direction (the direction intersecting the A scan direction) based on the layer thickness identified by the layer thickness identifying unit 262. That is, the layer thickness variation amount profile generating unit 264 generates the layer thickness variation amount profile by sequentially calculating the difference in layer thickness between A lines adjacent in the B scan direction for each scan angle of the A line.

[0109] In some embodiments, the characteristic positions of the layer thickness variation are identified based on the layer thickness variation profile generated by the layer thickness variation profile generating unit 264.

[0110] 7 and 8 show examples of layer thickness change profiles according to the embodiment. Fig. 7 schematically shows the layer thickness change profile in a normal eye. Fig. 8 schematically shows the layer thickness change profile in a CSC eye.

[0111] 7 shows a schematic example of a layer thickness change amount profile displayed on the display unit 240A in association with a tomographic image IMG1 of a normal eye. That is, the position of the A-line in the tomographic image IMG1 is displayed so as to vertically coincide with the position of the A-line in the layer thickness change amount profile. In FIG. 7, the horizontal axis of the characteristic graph showing the layer thickness change amount profile etc. represents the pixel position (A-line position, A-scan position) of the tomographic image corresponding to the scan angle (imaging angle of view), the left vertical axis represents thickness, and the right vertical axis represents the amount of layer thickness change.

[0112] When OCT data is acquired by performing OCT on a normal eye to be examined, the layer region identifying unit 261 identifies the choroid as described above using the acquired OCT data. The layer thickness identifying unit 262 identifies the layer thickness of the choroid in the A-scan direction identified by the layer region identifying unit 261 as described above. By identifying the layer thickness for each pixel position, a choroidal layer thickness profile T1 as shown in FIG. 7 is acquired.

[0113] The moving average processing unit 2631 generates a layer thickness profile T2 after moving average processing by sequentially calculating the moving average of the layer thicknesses of multiple A lines within a 10-degree scan angle range adjacent to the B scan direction for the layer thickness profile T1.

[0114] The maximum value identifying unit 2632 identifies the maximum value of the amount of change in layer thickness by analyzing the layer thickness profile T2 over the entire range from pixel position 0 to pixel position 2047. The characteristic position identifying unit 263 identifies the position indicating the maximum value identified by the maximum value identifying unit 2632 as the characteristic position P1 indicating the maximum value of choroidal change.

[0115] The layer thickness variation amount profile generating unit 264 generates a layer thickness variation amount profile T3 by calculating the difference in layer thickness between adjacent A-lines for the layer thickness profile T2 after the moving average process.

[0116] 7, the display control unit 211A causes the display unit 240A to display a triangular mark (information) indicating a position corresponding to the characteristic position P1 in the layer thickness change amount profile T3. The display control unit 211A also causes the display unit 240A to display information indicating the change amount at the characteristic position P1 in the layer thickness change amount profile T3 (for example, a solid line segment, a dashed line segment, or information indicating a range). In some embodiments, the display control unit 211A causes the display unit 240A to display information indicating the layer thickness at the characteristic position P1 in the layer thickness change amount profile T3.

[0117] 8 is a schematic diagram showing an example in which a layer thickness change amount profile is displayed on the display unit 240A in association with a tomographic image IMG2 of a CSC eye (an eye with CSC). That is, the position of the A-line in the tomographic image IMG2 is displayed so as to vertically coincide with the position of the A-line in the layer thickness change amount profile. In FIG. 8, the horizontal axis of the characteristic graph showing the layer thickness change amount profile etc. represents the pixel position of the tomographic image corresponding to the scan angle, the left vertical axis represents thickness, and the right vertical axis represents the amount of layer thickness change.

[0118] When OCT data is acquired by performing OCT on the CSC eye, the layer region identifying unit 261 identifies the choroid as described above using the acquired OCT data. The layer thickness identifying unit 262 identifies the layer thickness of the choroid in the A-scan direction identified by the layer region identifying unit 261 as described above. By identifying the layer thickness for each pixel position, a choroidal layer thickness profile T11 as shown in FIG. 8 is acquired.

[0119] The moving average processing unit 2631 generates a layer thickness profile T12 after moving average processing by sequentially calculating the moving average of the layer thicknesses of multiple A lines within a 10-degree scan angle range adjacent to the B scan direction for the layer thickness profile T11.

[0120] The maximum value identifying unit 2632 identifies the maximum value of the amount of change in layer thickness by analyzing the layer thickness profile T12 over the entire range from pixel position 0 to pixel position 2047. The characteristic position identifying unit 263 identifies the position indicating the maximum value identified by the maximum value identifying unit 2632 as the characteristic position P2 indicating the maximum value of choroidal change.

[0121] The layer thickness variation amount profile generating unit 264 generates a layer thickness variation amount profile T13 by calculating the difference in layer thickness between adjacent A-lines for the layer thickness profile T12 after the moving average process.

[0122] 8, the display control unit 211A causes the display unit 240A to display a triangular mark indicating a position corresponding to the characteristic position P2 in the layer thickness change amount profile T13. The display control unit 211A also causes the display unit 240A to display information indicating the amount of change at the characteristic position P2 in the layer thickness change amount profile T13 (for example, a solid line segment, a dashed line segment, or information indicating a range). In some embodiments, the display control unit 211A causes the display unit 240A to display information indicating the layer thickness at the characteristic position P2 in the layer thickness change amount profile T13.

[0123] As shown in Figures 7 and 8, the feature positions differ between normal eyes and CSC eyes. This difference in feature positions can be a significant parameter (information) for identifying CSC eyes. Therefore, based on the feature positions, it is possible to identify areas that require continuous attention and to assess the risk of CSC.

[0124] <Risk Assessment Department 265> The risk determination unit 265 determines the risk of CSC (disease) based on the amount of change in layer thickness at a characteristic position in the layer thickness change amount profile. The risk determination unit 265 can determine the risk of CSC by referring to the risk determination information 212A.

[0125] FIG. 9 shows an outline of the configuration of the risk assessment information 212A according to the embodiment.

[0126] The risk assessment information 212A is standard data (reference data, statistical data) in which risk information indicating the risk of CSC is previously associated with layer thickness change amounts at characteristic positions in the layer thickness change amount profile for a plurality of test eyes. Specifically, the risk assessment information 212A is table information in which risk information RK1, RK2, . . ., RKn is previously associated with a plurality of layer thickness change amounts LT1, LT2, . . ., LTn (n is an integer of 2 or more). Each of the risk information RK1, RK2, . . ., RKn includes at least one of whether or not there is CSC (disease) (presence or absence of disease) and the probability of CSC (possibility of disease).

[0127] In some embodiments, the risk assessment information 212A is statistical data for a plurality of normal eyes. In some embodiments, the risk assessment information 212A is statistical data for a plurality of CSC eyes.

[0128] The risk determination unit 265 refers to the risk determination information 212A based on the amount of layer thickness change at the feature position identified by the feature position identifying unit 263 (the maximum value of the amount of layer thickness change identified by the maximum value identifying unit 2632), and identifies risk information corresponding to the amount of layer thickness change. From the identified risk information, the risk determination unit 265 can generate a risk determination result including at least one of whether or not the subject's eye is CSC and the probability that the subject's eye is CSC.

[0129] In some embodiments, the risk assessment unit 265 refers to the risk assessment information 212A based on the layer thickness change amount, identifies two or more pieces of risk information corresponding to two or more layer thickness change amounts close to the layer thickness change amount, and generates one piece of risk information corresponding to the layer thickness change amount from the identified two or more pieces of risk information.

[0130] In some embodiments, the risk determination unit 265 determines the risk of CSC in the test eye E based on two pieces of risk information obtained by referring to statistical data on multiple normal eyes and statistical data on multiple CSC eyes, based on the amount of change in choroidal thickness at a characteristic position of the test eye E.

[0131] In some embodiments, the risk assessment information 212A includes a plurality of pieces of risk assessment information corresponding to a plurality of distances from a characteristic site (e.g., a macular region) on the fundus to a characteristic position. In this case, the risk assessment unit 265 can identify risk assessment information corresponding to the distance between the characteristic site and the characteristic position from the plurality of pieces of risk assessment information, and use the identified risk assessment information to identify risk information corresponding to the amount of change in layer thickness.

[0132] In some embodiments, the risk assessment information 212A includes a plurality of pieces of risk assessment information corresponding to a plurality of imaging angles of view, respectively. In this case, the risk assessment unit 265 can identify the risk assessment information corresponding to the imaging angle of view from the plurality of pieces of risk assessment information, and use the identified risk assessment information to identify the risk information corresponding to the amount of change in layer thickness.

[0133] In some embodiments, the display control unit 211A causes the display unit 240A to display information corresponding to the risk information identified by the risk determination unit 265 as described above.

[0134] 7 and 8, the case where the maximum value of the amount of change in layer thickness is used as the choroidal change maximum value to identify the characteristic position is described, but the embodiment is not limited to this. The characteristic position identifying unit 263 may identify the maximum value of the amount of change in layer thickness for each of a plurality of pixel position ranges as the choroidal change maximum value, and identify a plurality of characteristic positions that indicate the identified choroidal change maximum values.

[0135] FIG. 10 shows another example of a layer thickness profile according to the embodiment.

[0136] 7 and 8, Fig. 10 schematically shows an example in which a layer thickness profile is displayed on the display unit 240A in association with a tomographic image IMG3 of the subject's eye. That is, the position of the A-line in the tomographic image IMG3 is displayed so as to vertically coincide with the position of the A-line in the layer thickness profile. In Fig. 10, the horizontal axis of the characteristic graph showing the layer thickness profile etc. represents the pixel position of the tomographic image corresponding to the scan angle, and the vertical axis represents the thickness.

[0137] When OCT data is acquired by performing OCT on the subject's eye, the layer region identifying unit 261 identifies the choroid as described above using the acquired OCT data. The layer thickness identifying unit 262 identifies the layer thickness of the choroid in the A-scan direction identified by the layer region identifying unit 261 as described above. By identifying the layer thickness for each pixel position, a choroidal layer thickness profile T31 as shown in FIG. 10 is acquired.

[0138] The moving average processing unit 2631 generates a layer thickness profile T32 after moving average processing by sequentially calculating the moving average of the layer thicknesses of multiple A lines within a 10-degree scan angle range adjacent to the B scan direction for the layer thickness profile T31.

[0139] The characteristic position identifying unit 263 (maximum value identifying unit 2632) identifies the maximum value of the amount of change in layer thickness in the B-scan direction for each of three predetermined ranges within the range from pixel position 0 to pixel position 2047. The characteristic position identifying unit 263 identifies the positions indicating the maximum values ​​identified by the maximum value identifying unit 2632 as characteristic positions P21, P31, and P41 indicating maximum values ​​of choroidal change.

[0140] At least one of the three ranges may be identified by analyzing the tomographic image IMG3 by the data processing unit 230, or may be designated by the user using the operation unit 240B.

[0141] The layer thickness variation amount profile generating unit 264 can generate a layer thickness variation amount profile (not shown) by calculating the difference in layer thickness between adjacent A-lines for the layer thickness profile T32 after the moving average process.

[0142] The display control unit 211A causes the display unit 240A to display information indicating positions corresponding to the characteristic positions P21, P31, and P41 in the layer thickness profiles T31 and T32.

[0143] In some embodiments, the display controller 211A controls the display unit 240A to display information (indicators) (e.g., vertical line segments at the characteristic positions) representing the amount of layer thickness change at the characteristic positions P21, P31, and P41 of the layer thickness profiles T31 and T32. In this case, the display controller 211A controls the display unit 240A to display information Q21, Q31, and Q41 (the slope of the tangent at the characteristic position of the layer thickness profile) representing the slope corresponding to the amount of layer thickness change at the characteristic positions P21, P31, and P41 of the layer thickness profiles T31 and T32. In some embodiments, the information Q21, Q31, and Q41 representing the slope is displayed in a manner (color) corresponding to the magnitude of the slope. The larger the slope, the larger the amount of layer thickness change. For example, the information Q21, Q31, and Q41 representing the slope is displayed in a manner that calls the user's attention as the slope increases. For example, the degree of suspicion of a CSC eye from a normal eye can be expressed by the angle of the slope and the color of the information representing the slope.

[0144] In the above embodiment, the maximum amount of change in choroidal layer thickness is identified as the choroidal change maximum value, and the position indicating the choroidal change maximum value is identified. However, the configuration according to the embodiment is not limited to this. For example, by determining whether the choroidal change maximum value and the position of the second largest amount of change in choroidal layer thickness are located at positions that are point-symmetric with respect to the macula, it is possible to detect the shape of the eyeball and estimate the presence or absence (or probability of the presence) of a disease caused by the shape of the eyeball.

[0145] <User Interface 240> 3, the user interface 240 includes a display unit 240A and an operation unit 240B. The display unit 240A includes the display device 3. The operation unit 240B includes various operation devices and input devices.

[0146] The user interface 240 may include a device that combines a display function and an operation function, such as a touch panel. In other embodiments, at least a portion of the user interface may not be included in the ophthalmic device. For example, the display device may be an external device connected to the ophthalmic device.

[0147] <Communications Department 280> The communication unit 280 has a function for communicating with an external device (not shown). The communication unit 280 has a communication interface according to the connection form with the external device. Examples of external devices include a server device, an OCT device, a scanning optical ophthalmoscope, a slit lamp ophthalmoscope, an ophthalmic measurement device, and an ophthalmic treatment device. Examples of ophthalmic measurement devices include an eye refraction examination device, a tonometer, a specular microscope, a wavefront analyzer, a perimeter, and a microperimeter. Examples of ophthalmic treatment devices include a laser treatment device, a surgical device, and a surgical microscope. The external device may also be a device (reader) that reads information from a recording medium or a device (writer) that writes information to a recording medium. Furthermore, the external device may also be a hospital information system (HIS) server, a DICOM (Digital Imaging and Communication in Medicine) server, a doctor's terminal, a mobile terminal, a personal terminal, a cloud server, etc.

[0148] The arithmetic and control unit 200 (the control unit 210, the image forming unit 220, and the data processing unit 230) is an example of an "ophthalmologic information processing device" according to the embodiment. CSC is an example of a "disease" according to the embodiment. The display unit 240A (the display device 3) is an example of a "display means" according to the embodiment. The moving average processing unit 2631 is an example of a "smoothing unit" according to the embodiment. The optical system from the OCT unit 100 to the objective lens 22 is an example of an "OCT optical system" according to the embodiment.

[0149] <Operation> An example of the operation of the ophthalmologic apparatus 1 will be described.

[0150] 11 to 14 show an example of operation of the ophthalmic apparatus 1 according to the embodiment. FIG. 11 shows a flow diagram of an example of operation of the ophthalmic apparatus 1 performing risk assessment. FIG. 12 shows a flow diagram of an example of operation of the ophthalmic apparatus 1 performing the processing of step S4 in FIG. 11. FIG. 13 shows a flow diagram of an example of operation of the ophthalmic apparatus 1 performing the processing of step S14 in FIG. 12. FIG. 14 shows a flow diagram of another example of operation of the ophthalmic apparatus 1 performing the processing of step S4 in FIG. 11.

[0151] The storage unit 212 stores a computer program for realizing the processes shown in Figures 11 to 14. The main control unit 211 operates in accordance with this computer program to execute the processes shown in Figures 11 to 14.

[0152] First, an example of operation shown in FIG. 11 will be described.

[0153] (S1: Alignment) First, the main control unit 211 performs alignment.

[0154] For example, the main controller 211 controls the LCD 39 to present a fixation target for alignment to the subject's eye E. The main controller 211 controls the anterior-segment cameras 5A and 5B to capture images of the anterior segment Ea of the subject's eye E substantially simultaneously. Under control of the main controller 211, the characteristic site identification unit 251 analyzes the pair of anterior-segment images captured substantially simultaneously by the anterior-segment cameras 5A and 5B to identify the pupil center position of the subject's eye E as the characteristic site. The three-dimensional position calculation unit 252 calculates the three-dimensional position of the subject's eye E. This processing includes, for example, calculation processing using trigonometry based on the positional relationship between the pair of anterior-segment cameras 5A and 5B and the subject's eye E, as described in Japanese Patent Application Laid-Open No. 2013-248376.

[0155] The main control unit 211 controls the movement mechanism 150 based on the three-dimensional position of the subject's eye E obtained by the three-dimensional position calculation unit 252 so that the optical system (e.g., the fundus camera unit 2) and the subject's eye E have a predetermined positional relationship. Here, the predetermined positional relationship is a positional relationship that allows imaging and examination of the subject's eye E to be performed using the optical system. As a typical example, when the three-dimensional position (x coordinate, y coordinate, z coordinate) of the subject's eye E is obtained by the three-dimensional position calculation unit 252, a position where the x coordinate and y coordinate of the optical axis of the objective lens 22 coincide with the x coordinate and y coordinate of the subject's eye E, respectively, and where the difference between the z coordinate of the objective lens 22 (front lens surface) and the z coordinate of the subject's eye E (corneal surface) is equal to a predetermined distance (working distance) is set as the movement destination of the optical system.

[0156] (S2: Autofocus) Next, the main control unit 211 starts autofocus.

[0157] For example, the main controller 211 controls the focus optical system 60 to project a split index onto the subject's eye E. Under the control of the main controller 211, the data processor 230 analyzes the observation image of the fundus Ef onto which the split index is projected, thereby extracting a pair of split index images and calculating the relative deviation between the pair of split indexes. The main controller 211 controls the focus driver 31A and the focus driver 43A based on the calculated deviation (deviation direction, deviation amount).

[0158] (S3: OCT measurement) Next, the main controller 211 executes OCT measurement.

[0159] For example, the main controller 211 displays a fixation target for OCT measurement at a predetermined position on the LCD 39. The main controller 211 can display the fixation target at a display position on the LCD 39 that corresponds to the position of the optical axis of the optical system on the fundus Ef.

[0160] Next, the main controller 211 controls the OCT unit 100 to perform provisional OCT measurement and acquire an adjustment tomographic image for adjusting the reference position of the measurement range in the depth direction. Specifically, the main controller 211 controls the optical scanner 42 to deflect the measurement light LS generated based on the light L0 emitted from the light source unit 101 and scan a predetermined site of the subject's eye E (e.g., the fundus) with the deflected measurement light LS. The detection result of the interference light obtained by scanning the measurement light LS is sampled in synchronization with a clock KC and then sent to the image forming unit 220. The image forming unit 220 forms a tomographic image (OCT image) of the subject's eye E from the obtained interference signal.

[0161] Next, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction).

[0162] For example, the main controller 211 causes the data processor 230 to identify a predetermined region (e.g., the sclera) in the acquired tomographic image, and sets a position a predetermined distance in the depth direction from the position of the identified predetermined region as the reference position of the measurement range. The main controller 211 controls at least one of the optical path length changer 41 and the reference driver 114A in accordance with the reference position. Alternatively, a predetermined position may be set as the reference position of the measurement range so that the optical path lengths of the measurement light LS and the reference light LR are approximately the same.

[0163] Next, the main control unit 211 executes focus adjustment control and polarization adjustment control.

[0164] For example, the main controller 211 controls the focus driver 43A to move the OCT focusing lens 43 by a predetermined distance, and then controls the OCT unit 100 to perform OCT measurement. The main controller 211 causes the data processor 230 to determine the focus state of the measurement light LS based on the detection result of the interference light obtained by the OCT measurement. When it is determined that the focus state of the measurement light LS is not appropriate based on the determination result by the data processor 230, the main controller 211 controls the focus driver 43A again, and repeats this process until it is determined that the focus state is appropriate.

[0165] Furthermore, for example, the main control unit 211 controls at least one of the polarization controllers 103, 118 to change the polarization state of at least one of the light L0 and the measurement light LS by a predetermined amount, and then controls the OCT unit 100 to perform OCT measurement and causes the image forming unit 220 to form an OCT image based on the detection result of the acquired interference light. The main control unit 211 causes the data processing unit 230 to determine the image quality of the OCT image obtained by the OCT measurement. When it is determined based on the determination result by the data processing unit 230 that the polarization state of the measurement light LS is not appropriate, the main control unit 211 again controls the polarization controllers 103, 118, and repeats this process until it is determined that the polarization state is appropriate.

[0166] Next, the main control unit 211 controls the OCT unit 100 to perform OCT measurement. The detection result of the interference light acquired by the OCT measurement is sampled by the DAQ 130 and stored as an interference signal in the storage unit 212 or the like.

[0167] For example, the main control unit 211 causes the image forming unit 220 to form a set of data sets of A-scan image data of the subject's eye E based on the acquired interference signals. The image forming unit 220 forms a tomographic image by arranging the formed A-scan images in the B-scan direction.

[0168] (S4: Risk assessment process) Next, the main control unit 211 controls the risk assessment processing unit 260 in the data processing unit 230 to execute a risk assessment process for CSC based on the OCT data or tomographic image acquired in step S3.

[0169] Step S4 will be described in detail later.

[0170] This is the end of the operation of the ophthalmologic apparatus 1 (END).

[0171] The process of step S4 in FIG. 11 is executed as shown in FIG.

[0172] (S11: Identify BM and CSI) The main controller 211 controls the layer region specifying part 261 to specify the Bruch membrane (BM) and the CSI based on the OCT data acquired in step S3 of Fig. 11 as described above. As a result, the layer region specifying part 261 can specify the choroid.

[0173] (S12: Identify the layer thickness between BM and CSI) Next, the main controller 211 controls the layer thickness determination unit 262 to determine the layer thickness between the BM and the CSI determined in step S11 for each A-line, as described above. As a result, the layer thickness determination unit 262 can generate a choroidal layer thickness profile.

[0174] (S13: Moving average processing) Next, the main controller 211 controls the moving average processor 2631 to sequentially calculate a moving average of the choroidal layer thickness data identified in step S12 in the B-scan direction within a scan angle range of 10 degrees. As a result, the moving average processor 2631 can generate choroidal layer thickness data after moving average processing.

[0175] (S14: Identify the characteristic position of the layer thickness change amount) Next, the main controller 211 controls the characteristic position identifying unit 263 to calculate the difference in layer thickness (layer thickness change amount) between adjacent A-lines for the choroidal layer thickness data after the moving average process obtained in step S13. The main controller 211 controls the characteristic position identifying unit 263 to identify the characteristic position of the layer thickness change amount from the calculated layer thickness difference.

[0176] For example, the layer thickness change amount profile generating unit 264 generates a layer thickness change amount profile from the layer thickness change amounts sequentially identified in step S14. In some embodiments, a characteristic position of the layer thickness change amount is identified from the layer thickness change amount profile generated by the layer thickness change amount profile generating unit 264.

[0177] Step S14 will be described in detail later.

[0178] (See S15: Risk Assessment Information) Subsequently, the main control unit 211 controls the risk determination unit 265 to refer to the risk determination information 212A based on the amount of change in layer thickness at the characteristic position identified in step S14. The risk determination unit 265 identifies risk information corresponding to the amount of change in layer thickness identified in step S14 from the risk determination information 212A.

[0179] (S16: Risk assessment) Next, the main control unit 211 controls the risk determination unit 265 to determine the risk of CSC for the subject's eye E based on the risk information identified in step S15. The risk determination unit 265 generates a risk determination result including at least one of whether the subject's eye E is CSC or not and the probability that the subject's eye is CSC, from the identified risk information.

[0180] (S17:Display) Subsequently, the display control unit 211A causes the display unit 240A to display the characteristic positions identified in step S14, the layer thickness change amounts at the characteristic positions, and the risk assessment results obtained in step S16.

[0181] In some embodiments, the display control unit 211A causes the display unit 240A to display information indicating the gradient corresponding to the amount of change in layer thickness at the characteristic position, as shown in FIG.

[0182] This is the end of the process in step S4 of FIG. 11 (END).

[0183] The process of step S14 in Fig. 12 is executed as shown in Fig. 13. Fig. 13 shows a process example in which a position showing the maximum value of the layer thickness variation is identified as a characteristic position of the layer thickness variation profile. Before executing the process in Fig. 13, it is assumed that the maximum value of the layer thickness variation is initialized (for example, the maximum value is initialized to "0" or a negative value).

[0184] (S21: Calculate the scan angle for one A-line) First, the feature position identifying unit 263 calculates the scan angle for one A-line centered on the scan center position of the OCT scan. The imaging angle of view is a known design value specific to the ophthalmic apparatus 1, determined by the arrangement of the optical system of the ophthalmic apparatus 1, etc. Furthermore, the range of the measurement positions (positions of the A-lines) of the A-scan arranged in the B-scan direction corresponds to the number of pixels in the B-scan direction in the tomographic image. The number of pixels in the B-scan direction in the tomographic image is also determined in advance. Therefore, the feature position identifying unit 263 calculates the scan angle for each A-line by dividing the imaging angle of view, which is known specific to the ophthalmic apparatus 1, by the known number of pixels in the B-scan direction in the tomographic image.

[0185] (S22: Calculate the difference in layer thickness between adjacent A-lines) Next, the maximum value identifying part 2632 in the characteristic position identifying part 263 obtains, for example, the difference in layer thickness between adjacent A-lines in the tomographic image of the eye E, spaced apart by the scan angle calculated in step S21.

[0186] (S23: Identify the gradient of layer thickness) Next, the maximum value identification unit 2632 identifies the gradient of the layer thickness as the amount of change in the layer thickness by dividing the difference in layer thickness calculated in step S22 by the scan angle for one A-line calculated in step S21.

[0187] (S24: Slope > Maximum?) Next, the maximum value identifying part 2632 determines whether or not the gradient of the layer thickness calculated in step S23 exceeds the maximum value.

[0188] In step S24, when it is determined that the calculated gradient of the layer thickness exceeds the maximum value (step S24: Y), the process of step S14 in Fig. 12 proceeds to step S25. In step S24, when it is determined that the calculated gradient of the layer thickness does not exceed the maximum value (S24: N), the process of step S14 in Fig. 12 proceeds to step S26.

[0189] (S25: Update the maximum slope value) In step S24, when it is determined that the calculated gradient of the layer thickness exceeds the maximum value (step S24: Y), the maximum value specifying part 2632 updates the gradient calculated in step S23 as the maximum value.

[0190] (S26: The next A-line?) Following step S25, or in step S24, when it is determined that the calculated gradient of the layer thickness does not exceed the maximum value (S24: N), the maximum value identification unit 2632 determines whether to continue calculating the gradient of the layer thickness for the next A-line.

[0191] The maximum value identification unit 2632 can determine whether to continue calculating the layer thickness gradient for the next A-line by determining whether steps S22 to S25 have been repeated a predetermined number of times for the A-lines.

[0192] In step S26, when it is determined that the calculation of the layer thickness gradient for the next A-line is to be continued (step S26: Y), the process of step S14 in Fig. 12 proceeds to step S22. In step S26, when it is determined that the calculation of the layer thickness gradient for the next A-line is not to be continued (step S26: N), the process of step S14 in Fig. 12 proceeds to step S27.

[0193] (S27: Generate a layer thickness change profile) In step S26, when it is determined not to continue calculating the layer thickness gradient for the next A line (step S26: N), the main control unit 211 controls the layer thickness variation amount profile generating unit 264 to generate a layer thickness variation amount profile indicating the amount of change in layer thickness along the B scan direction, using the layer thickness gradient obtained by repeatedly executing step S23 as the layer thickness variation amount.

[0194] This is the end of the process in step S14 in FIG. 12 (END).

[0195] Furthermore, the process of step S4 in Fig. 11 is not limited to the process shown in Fig. 12. For example, the process of step S4 in Fig. 11 may be executed as shown in Fig. 14.

[0196] (S31: Identify BM and CSI) As in step S11, the main controller 211 controls the layer region specifying part 261 to specify the Bruch's membrane (BM) and the CSI based on the OCT data acquired in step S3 of Fig. 11, as described above. As a result, the layer region specifying part 261 can specify the choroid.

[0197] (S32: Identify the layer thickness between BM and CSI) Next, similarly to step S12, the main controller 211 controls the layer thickness determination unit 262 to determine the layer thickness between the BM and the CSI determined in step S31 for each A-line. As a result, the layer thickness determination unit 262 can generate a choroidal layer thickness profile.

[0198] (S33: Moving average processing) Next, similarly to step S13, the main controller 211 controls the moving average processor 2631 to sequentially calculate a moving average of the choroidal layer thickness data identified in step S32 in the B-scan direction within a scan angle range of 10 degrees. As a result, the moving average processor 2631 can generate choroidal layer thickness data after moving average processing.

[0199] (S34: Identify the characteristic position of the layer thickness change amount) Next, similarly to step S14, the main controller 211 controls the characteristic position identifying unit 263 to calculate the difference in layer thickness (layer thickness change amount) between adjacent A-lines for the choroidal layer thickness data after moving average processing obtained in step S33. The main controller 211 controls the characteristic position identifying unit 263 to identify the characteristic position of the layer thickness change amount from the calculated layer thickness difference.

[0200] Also, in step S34, the main control unit 211 controls the layer thickness change amount profile generation unit 264 to generate a layer thickness change amount profile representing the change amount of layer thickness along the B-scan direction based on the layer thickness change amount identified in step S34.

[0201] (See S35: Risk Assessment Information) Next, similarly to step S15, the main control unit 211 controls the risk determination unit 265 to refer to the risk determination information 212A based on the amount of change in layer thickness at the characteristic position identified in step S14. The risk determination unit 265 identifies risk information corresponding to the amount of change in layer thickness identified in step S14 from the risk determination information 212A.

[0202] (S36: Risk assessment) Next, similarly to step S16, the main control unit 211 controls the risk determination unit 265 to determine the risk of CSC for the subject's eye E based on the risk information identified in step S15. The risk determination unit 265 generates a risk determination result including at least one of whether the subject's eye E is CSC or not and the probability that the subject's eye is CSC, from the identified risk information.

[0203] (S37: Display the tomographic image and the layer thickness change profile) Next, the display control unit 211A causes the display unit 240A to display the tomographic image formed in step S3 of Fig. 11 and the layer thickness change amount profile generated in step S34. For example, the display control unit 211A causes the display unit 240A to display the tomographic image and the layer thickness change amount profile as shown in Fig. 7 or 8.

[0204] In step S37, the display control unit 211A can display the layer thickness profile or the layer thickness profile after moving average processing on the display unit 240A in addition to the tomographic image and the layer thickness change amount profile, as shown in Figure 7, Figure 8, or Figure 10.

[0205] (S38: Display additional information) Subsequently, the display control unit 211A causes the display unit 240A to display various types of incidental information so as to be superimposed on the tomographic image and the layer thickness change amount profile. Examples of the incidental information include a triangular mark (information) indicating a position corresponding to a characteristic position in the layer thickness change amount profile, information indicating the amount of change at the characteristic position in the layer thickness change amount profile, information indicating the layer thickness at the characteristic position in the layer thickness profile, and information indicating the gradient at the characteristic position in the layer thickness profile.

[0206] This is the end of the process in step S4 of FIG. 11 (END).

[0207] [Variations] In the above embodiment, the display controller 211A may cause the display unit 240A to display a tomographic image that has been subjected to shape correction so as to match the actual shape of the eyeball. In this case, the data processor performs shape correction on the OCT data or the tomographic image of the subject's eye. The display controller 211A causes the display unit 240A to display the corrected tomographic image formed based on the OCT data that has been subjected to shape correction, or the tomographic image that has been subjected to shape correction.

[0208] The following describes the modifications of the embodiment, focusing on the differences from the embodiment.

[0209] The configuration of the optical system of the ophthalmic apparatus according to the modified embodiment is the same as the configuration of the optical system of the ophthalmic apparatus 1 according to the embodiment. The configuration of the processing system of the ophthalmic apparatus according to the modified embodiment differs from the configuration of the processing system of the ophthalmic apparatus 1 according to the embodiment in that a data processing unit 230a is provided instead of the data processing unit 230.

[0210] A block diagram of a configuration example of a data processing unit 230a according to a modified example of the embodiment is shown in Fig. 15. In Fig. 15, the same parts as in Fig. 4 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0211] The configuration of the data processing unit 230a differs from the configuration of the data processing unit 230 in that an actual shape correction unit 300 is added to the data processing unit 230a.

[0212] (Actual shape correction unit 300) The shape correction unit 300 performs shape correction on the OCT data of the subject's eye E or an OCT image (tomographic image) formed by the image formation unit 220 based on the OCT data of the subject's eye E. The shape correction unit 300 corrects two-dimensional or three-dimensional OCT data (scan data) or an OCT image obtained by scanning the inside of the eye with measurement light LS using an optical scanner 42 arranged approximately optically conjugate with the pupil (predetermined site) of the subject's eye E. The OCT image is a two-dimensional image or a three-dimensional image. Examples of OCT images include a tomographic image of the fundus and a three-dimensional image of the fundus.

[0213] The actual shape correction unit 300 identifies a transformation position along the A-scan direction (the direction of travel of the measurement light passing through the scan center position) that corresponds to a pixel position in an OCT image or a scan position in two-dimensional or three-dimensional scan data. The actual shape correction unit 300 converts the pixel position or scan position to a transformation position identified based on the pixel position, etc. The transformation position is a position in a predetermined coordinate system. The predetermined coordinate system is defined by two or more coordinate axes, including at least one coordinate axis in the same axial direction as the scan direction of the A-scan.

[0214] In some embodiments, the actual shape correction unit 300 identifies the transformation position based on parameters (such as the axial length) that represent optical characteristics of the subject's eye E. In some embodiments, the actual shape correction unit 300 identifies at least one of a first axis direction component and a second axis direction component intersecting with the first axis direction of the transformation position in a predetermined coordinate system based on the scan radius in the A-scan direction, the scan angle, the depth range in which OCT measurement is possible, and the pixel position or the scan position.

[0215] An explanatory diagram of a comparative example of the embodiment is shown in Fig. 16. Fig. 16 is a diagram schematically showing the path of measurement light incident on the eye E to be inspected.

[0216] For example, the measurement light deflected by the optical scanner 42 is incident at various angles on the pupil of the subject's eye E, which is the scan center position, as shown in Fig. 16. The measurement light incident on the subject's eye E is projected toward various parts inside the eye, for example, around the scan center position Cs set at the center of the pupil.

[0217] An A-scan image is formed from interference data obtained using the measuring light LS1 in Fig. 16, an A-scan image is formed from interference data obtained using the measuring light LS2, and an A-scan image is formed from interference data obtained using the measuring light LS3. A tomographic image of the fundus Ef is formed by arranging a plurality of A-scan images formed in this manner.

[0218] In this way, the A-scan direction changes within the scan angle range centered on the scan center position Cs, and the shape of the area is deformed in the tomographic image in which the obtained multiple A-scan images are arranged horizontally. The wider the angle of view, the greater the difference from the actual shape.

[0219] Morphological information representing the shape of the subject's eye E can be obtained from the position of any pixel in the tomographic image. Such morphological information includes the thickness of a layer region, the distance between regions, the area of ​​a region, the volume of a region, the perimeter of a region, the direction of a region relative to a reference position, the angle of a region relative to the reference direction, the radius of curvature of a region, and the like.

[0220] For example, the thickness of a layer region (or the distance between regions) as morphological information can be determined by measuring the distance between any two points in a tomographic image. In this case, the distance between the two points is determined by the number of pixels in the tomographic image and is measured by multiplying the determined number of pixels by the pixel size specific to the device. The same pixel size is used for all pixels in the tomographic image. However, as mentioned above, because the scanning direction varies around the scan center position Cs, the horizontal pixel size of the tomographic image varies depending on the depth position in the scanning direction. For example, when the depth range is 2.5 mm and the same pixel size is used for all pixels in the tomographic image, there is an approximately 13% difference in the B-scan scan length between the top and bottom of the tomographic image, and when the depth range is 10 mm, there is an approximately 50% difference.

[0221] Therefore, the actual shape correction unit 300 performs coordinate conversion of pixel positions in the acquired OCT image or scan positions in the scan data.

[0222] The following mainly describes the case where the actual shape correction unit 300 performs actual shape correction on a tomographic image formed based on OCT data of the subject's eye E. When the actual shape correction unit 300 performs actual shape correction on OCT data (scan data), the "pixel position" in the tomographic image can be read as the "scan position" in the OCT data.

[0223] FIG. 17 shows a block diagram of an example of the configuration of the actual shape correction unit 300 shown in FIG.

[0224] The actual shape correction unit 300 includes a position identification unit 310 , a position conversion unit 320 , and an interpolation unit 330 .

[0225] (Location specifying unit 310) The position specifying unit 310 specifies a conversion position that corresponds to a pixel position in the acquired tomographic image and is along the traveling direction of the measurement light passing through the scan center position Cs. In some embodiments, the position specifying unit 310 uses ocular parameters (such as the axial length) of the subject's eye E or ocular parameters of the model eye in the process of specifying the conversion position.

[0226] Fig. 18 is a diagram illustrating the operation of the position specifying unit 310 according to the modified embodiment. In Fig. 18, the same parts as in Fig. 16 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0227] Here, the scan angle is φ, the scan radius is r, the depth range where OCT measurement is possible is d, the depth direction length of the tomographic image is h, and the lateral direction length of the tomographic image is w. The scan angle φ corresponds to the deflection angle of the measurement light LS centered on the scan center position Cs. The scan radius r corresponds to the distance from the scan center position Cs to the zero optical path length position where the measurement optical path length and the reference optical path length are approximately equal. The depth range d is a device-specific value (known) that is uniquely determined by the optical design of the device, etc.

[0228] The position identification unit 310 identifies a transformed position (X, Z) in the second coordinate system from a pixel position (x, z) in the first coordinate system. The first coordinate system has an origin at the upper left coordinate position in a tomographic image (OCT image, B-scan image), and is defined by an x-coordinate axis whose x-direction is the B-scan direction and a z-coordinate axis whose z-direction is perpendicular to the x-coordinate axis and whose z-direction is the A-scan direction. The pixel position (x, z) in the tomographic image is defined in the first coordinate system. The second coordinate system is defined by a Z-coordinate axis (e.g., second axis) whose Z-direction is the traveling direction of the measurement light LS, which has a scan angle of 0 degrees with respect to the measurement optical axis passing through a predetermined site (e.g., the fovea) on the fundus oculi Ef, and an X-coordinate axis (e.g., first axis) whose X-direction is the B-scan direction perpendicular to the Z-coordinate axis at the predetermined site. In the second coordinate system, a predetermined Z-position is defined as the origin of the Z-coordinate axis so that the position of the scan radius r is the deepest part of the measurement optical axis passing through the predetermined site (e.g., the fovea). Furthermore, a predetermined X position on the measurement light axis passing through a predetermined site (for example, the fovea) is set as the origin of the X coordinate axis so that the length in the depth direction is a predetermined length d as follows. The transformed position (X, Z) is defined in the second coordinate system. The transformed position (X, Z) corresponds to the pixel position (x, z) and is a position along the traveling direction (A-scan direction) of the measurement light LS passing through the scan center position Cs.

[0229] The position specifying unit 310 specifies a conversion position (X, Z) for the tomographic image based on the scan radius r in the A-scan direction, the scan angle φ, the depth range d where OCT measurement is possible, and the pixel position (x, z). The position specifying unit 310 can specify at least one of the X component (component in the first axis direction) and the Z component (component in the second axis direction) of the conversion position.

[0230] For an OCT image (tomographic image) with N A-scan line counts (N is a natural number), the conversion position (X, Z) corresponding to the pixel position (x, z) on the n-th A-scan line (n is a natural number) is determined as shown in Equations (1) and (2).

[0231]

number

[0232]

number

[0233] Here, the depth direction length h, the lateral direction length w, and the x component of the pixel position of the OCT image are expressed as in equations (3) to (5).

[0234]

number

[0235]

number

[0236]

number

[0237] In equations (1) and (2), the x coordinate of the pixel position is expressed as in equation (5). Therefore, the position identification unit 310 can identify the transformed position (X, Z) from the pixel position (x, z) based on the scan radius r, the scan angle φ, and the depth range d.

[0238] In some embodiments, the position identification unit 310 can identify the transformation position (X, Z) for the scan data based on the scan radius r in the A-scan direction, the scan angle φ, the depth range d in which OCT measurement is possible, and the scan position, as described above.

[0239] In some embodiments, the scan radius r is determined by analyzing the detection result of the interference light LC obtained using the OCT unit 100. This makes it possible to determine the transformation position (X, Z) that more accurately reflects the ocular optical characteristics of the subject's eye E.

[0240] In some embodiments, the position identifying unit 310 identifies the scan angle φ by performing ray tracing processing on the measurement light LS based on corneal shape information of the subject's eye E. The corneal shape information includes the corneal radius of curvature (the radius of curvature of the anterior surface of the cornea, the radius of curvature of the posterior surface of the cornea), the corneal thickness, etc. This makes it possible to identify a transformed position (X, Z) that more accurately reflects the ocular optical characteristics of the subject's eye E.

[0241] (Position conversion unit 320) The position converter 320 converts pixel positions (x, z) in the tomographic image to the transformed positions (X, Z) identified by the position identifier 310. In some embodiments, for each of all pixel positions in the tomographic image, the position identifier 310 identifies the transformed position, and the position converter 320 converts the pixel positions to the transformed positions.

[0242] This makes it possible to arrange the A-scan image acquired by A-scan in the A-scan direction, as shown in Fig. 19. Therefore, even if the angle of view is wide, it is possible to acquire a tomographic image in which the shape of a specific area is similar to the actual shape.

[0243] (Interpolation unit 330) The interpolation unit 330 interpolates pixels between the conversion positions. For example, as described above, pixel positions are converted to conversion positions, and the spacing between adjacent A-scan images changes depending on the distance from the scan center position Cs. The interpolation unit 330 interpolates pixels between A-scan images using pixels of adjacent A-scan images depending on the depth positions of the A-scan images. The pixel interpolation process performed by the interpolation unit 330 can employ known methods such as nearest neighbor interpolation, bilinear interpolation, and bicubic interpolation. In some embodiments, the interpolation unit 330 interpolates pixels between adjacent A-scan images depending on the distance from the scan center position Cs. For example, the interpolation unit 330 interpolates pixels between adjacent A-scan images by changing the interpolation process method depending on the distance from the scan center position Cs.

[0244] In some embodiments, the scan data is interpolated in a similar manner to that described above for scan positions in the scan data.

[0245] Fig. 20 shows an example of the flow of actual shape correction processing according to a modified example of the embodiment. A computer program for realizing the processing shown in Fig. 20 is stored in the storage unit 212. The main control unit 211 operates in accordance with this computer program to execute the processing shown in Fig. 20.

[0246] (S41: Calculate the transformation position) First, the main control unit 211 causes the position specifying unit 310 to specify a transformation position corresponding to a pixel position of the tomographic image. The position specifying unit 310 specifies the transformation position corresponding to the pixel position of the tomographic image as described above.

[0247] (S42: Convert pixel position) Next, the main control unit 211 controls the position conversion unit 320 to convert the pixel positions of the tomographic image into the converted positions calculated in step S41.

[0248] (S43:End?) The main control unit 211 determines whether or not to end the conversion of pixel positions.

[0249] When it is determined that there is a pixel position to be converted next (S43: N), the operation of the ophthalmologic apparatus 1 according to this modification proceeds to step S41. When it is determined that there is no pixel position to be converted next (S43: Y), the operation of the ophthalmologic apparatus 1 according to this modification proceeds to step S44.

[0250] In steps S41 to S43, a transformation position is identified and transformation to the identified transformation position is performed for each pixel position of the tomographic image.

[0251] (S44: Interpolation) In step S43, when it is determined that there is no pixel position to be converted next (S43: Y), the main control unit 211 causes the interpolation unit 330 to interpolate pixels between adjacent A-scan images converted to conversion positions in step S42.

[0252] This is the end of the actual shape correction process according to this modified example (END).

[0253] As shown in FIG. 7, FIG. 8, or FIG. 10, the display control unit 211A can cause the display unit 240A to display the layer thickness profile in association with the tomographic image that has been subjected to actual shape correction.

[0254] 21 is a schematic diagram showing an example in which a tomographic image after actual shape correction and a layer thickness profile are associated and displayed on the display unit 240A according to a modified example of the embodiment. In Fig. 21, the horizontal axis of the characteristic graph showing the layer thickness profile etc. represents the pixel position of the tomographic image corresponding to the scan angle, and the vertical axis represents the thickness.

[0255] When OCT data is acquired by performing OCT on the subject's eye, the layer region identifying unit 261 identifies the choroid as described above using the acquired OCT data. The layer thickness identifying unit 262 identifies the layer thickness of the choroid in the A-scan direction identified by the layer region identifying unit 261 as described above. By identifying the layer thickness for each pixel position, a choroidal layer thickness profile T41 as shown in FIG. 21 is acquired.

[0256] The moving average processing unit 2631 generates a layer thickness profile T42 after moving average processing by sequentially calculating the moving average of the layer thicknesses of multiple A lines within a 10-degree scan angle range adjacent to the B scan direction for the layer thickness profile T41.

[0257] For example, the characteristic position identifying unit 263 (maximum value identifying unit 2632) identifies the maximum value of the amount of change in the layer thickness from the layer thickness profile T42. The characteristic position identifying unit 263 identifies the position indicating the maximum value identified by the maximum value identifying unit 2632 as a characteristic position P51 indicating the maximum value of choroidal change.

[0258] The layer thickness variation amount profile generating unit 264 can generate a layer thickness variation amount profile (not shown) by calculating the difference in layer thickness between adjacent A-lines for the layer thickness profile T42 after the moving average process.

[0259] Furthermore, the shape correction unit 300 performs shape correction on the tomographic image formed by the image formation unit 220 based on the acquired OCT data, as described above. The display control unit 211A can display the layer thickness profiles T41 and T42 on the display unit 240A in association with the shape-corrected tomographic image (corrected tomographic image), as shown in FIG. 21 . In the shape-corrected tomographic image, A-scan images are arranged along an A-scan line (A-line) that extends in a direction corresponding to the scan angle, centered on the scan center position. This allows, for example, a doctor to visually explain to a patient a site suspected of CSC as a characteristic location, and makes it easier for the doctor to consider a treatment strategy or surgical strategy.

[0260] Furthermore, the display controller 211A may cause the display unit 240A to display information indicating a position corresponding to the characteristic position P51 in the layer thickness profiles T41 and T42. In some embodiments, the display controller 211A causes the display unit 240A to display the layer thickness variation profile in association with the tomographic image after actual shape correction.

[0261] In FIG. 21, the pixel position (angle of view) is such that the center position of the B scan line (for example, pixel position "1023" or "1024") is the 100% position, pixel position "0" is represented as the 0% position, and pixel position "2047" is represented as the 0% position. A line segment corresponding to the A scan line corresponding to the pixel position and numerical percentage information representing the pixel position are depicted in tomographic image IMG4 as a corrected tomographic image. In FIG. 21, the pixel position corresponding to characteristic position P51 is represented by a line segment representing the A scan line corresponding to characteristic position P51 and information representing the numerical value Pc (0≦Pc≦100)%. This makes it possible to easily identify a position corresponding to a characteristic position on a fundus having a curved shape.

[0262] In some embodiments, the display controller 211A causes the display unit 240A to display information (indicators) representing the amount of change in layer thickness at a characteristic position of the layer thickness profile (e.g., a vertical line segment at the characteristic position), as shown in FIG. 10. In this case, the display controller 211A causes the display unit 240A to display information representing the slope corresponding to the amount of change in layer thickness at a characteristic position P51 of the layer thickness profiles T41 and T42 (the slope of the tangent at the characteristic position of the layer thickness profile). For example, the information representing the slope is displayed in a manner that calls the user's attention as the slope increases. For example, the degree of suspicion of a CSC eye from a normal eye can be expressed by the angle of the slope and the color of the information representing the slope.

[0263] [Another variation] In this modification, a case where a two-dimensional OCT image (or two-dimensional scan data) is subjected to actual shape correction has been described, but the configuration according to the embodiment is not limited to this. The ophthalmologic apparatus according to the embodiment can correct a three-dimensional OCT image (or three-dimensional scan data) in the same manner as the above modification.

[0264] Fig. 22 is a diagram illustrating the operation of a position specifying unit according to another modified example of the embodiment. In Fig. 22, the same parts as in Fig. 18 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0265] In Fig. 22, a Y plane is defined in addition to the X plane and Z plane in Fig. 18. In addition to the parameters shown in Fig. 18, the central angle in the C-scan direction is defined as θ, and the length in the C-scan direction is defined as lc.

[0266] The position identification unit 310 identifies a transformed position (X, Y, Z) in the fourth coordinate system from a pixel position (x, y, z) in the third coordinate system. The third coordinate system has the coordinate position of the upper left corner of the three-dimensional OCT image as its origin, and is defined by an x-coordinate axis whose x-direction is the B-scan direction, a y-coordinate axis that is perpendicular to the x-coordinate axis and whose y-direction is the C-scan direction, and a z-coordinate axis that is perpendicular to both the x-coordinate axis and the y-coordinate axis and whose z-direction is the A-scan direction. The pixel position (x, y, z) in the OCT image is defined in the third coordinate system. The fourth coordinate system is defined by a Z-coordinate axis whose Z-direction is the traveling direction of the measurement light LS that passes through a predetermined site (e.g., the fovea) on the fundus oculi Ef and has a scan angle of 0 degrees with respect to the measurement optical axis, an X-coordinate axis whose X-direction is the B-scan direction that is perpendicular to the Z-coordinate axis at the predetermined site, and a Y-coordinate axis whose Y-direction is the C-scan direction that is perpendicular to the Z-coordinate axis at the predetermined site. In the fourth coordinate system, a predetermined Z position is set as the origin of the Z coordinate axis so that the position of scan radius r is the deepest part on the measurement optical axis passing through a predetermined site (e.g., the fovea centralis). Also, predetermined X and Y positions on the measurement optical axis passing through a predetermined site (e.g., the fovea centralis) are set as the origins of the X and Y coordinate axes so that the depth direction length is a predetermined d as described below. The transformation position (X, Y, Z) is defined in the fourth coordinate system. The transformation position (X, Y, Z) corresponds to the pixel position (x, y, z) and is a position along the traveling direction (A-scan direction) of the measurement light LS passing through the scan center position Cs.

[0267] The position determination unit 310 is capable of determining at least one of an X component, a Y component, and a Z component of the transformed position.

[0268] For an OCT image (tomographic image) in which the number of A scan lines is N (N is a natural number) and the number of B scan lines is M (M is a natural number), the conversion position (X, Y, Z) corresponding to the pixel position (x, y, z) on the nth (n is a natural number) A scan line of the mth (m is a natural number) B scan is determined as shown in equations (6) to (8).

[0269]

number

[0270]

number

[0271]

number

[0272] Here, the x and y components of the pixel position are expressed by equations (9) to (13) using the length h in the depth direction of the three-dimensional OCT image, the length w in the B-scan direction, and the length lc in the C-scan direction.

[0273]

number

[0274]

number

[0275]

number

[0276]

number

[0277]

number

[0278] In equations (6) to (8), the x and y coordinates of the pixel position are expressed as in equations (12) and (13). Therefore, the position specifying unit 310 can specify the converted position (X, Y, Z) from the pixel position (x, y, z) based on the scan radius r, scan angle φ, and depth range d.

[0279] In some embodiments, the position specifying unit 310 can specify the transformation position (X, Y, Z) for three-dimensional scan data (OCT data) in the same manner as described above.

[0280] The position converter 320 converts pixel positions (x, y, z) in the OCT image to the transformed positions (X, Y, Z) identified by the position identifier 310. In some embodiments, for each pixel position in the OCT image, the position identifier 310 identifies a transformed position, and the position converter 320 converts the pixel position to the transformed position. The interpolator 330 interpolates pixels between the transformed positions converted by the position converter 320.

[0281] In some embodiments, the display controller 211A causes the display unit 240A to display a three-dimensional OCT image in association with the layer thickness profile, instead of the tomographic image in Fig. 21. In this case, the display controller 211A may cause the three-dimensional OCT image to display positions corresponding to characteristic positions in the layer thickness profile in an identifiable manner.

[0282] In some embodiments, the display controller 211A causes the display unit 240A to display identifiable positions corresponding to characteristic positions in the layer thickness profile in a front image (C-scan image, projection image, or en-face image) formed from the 3D OCT data, the 3D OCT image, the 3D OCT data (scan data) after shape correction, or the 3D image after shape correction (3D OCT shape-corrected image). In this case, the display controller 211A may cause the display unit 240A to display identifiable positions corresponding to characteristic positions together with the OCT scan area in the front image.

[0283] In the above-described modified example of the embodiment or another modified example of the embodiment, a feature position identified from OCT data before shape correction is displayed in an identifiable manner in an OCT image (such as a tomographic image) after shape correction. However, the configuration of the embodiment is not limited to this. For example, shape correction may first be performed on the OCT data as described above, and a feature position of the change in film thickness in the A-scan direction of a predetermined layer region may be identified based on the shape-corrected OCT data. In this case, the shape correction unit 300 performs shape correction on the OCT data of the subject's eye E, and the layer thickness identification unit 262 identifies the layer thickness in the A-scan direction of a predetermined layer region (e.g., the choroid) based on the OCT data shape-corrected by the shape correction unit 300.

[0284] <Effect> An ophthalmological information processing apparatus, an ophthalmological apparatus, an ophthalmological information processing method, and a program according to an embodiment will be described.

[0285] An ophthalmologic information processing device (arithmetic and control unit 200 (control unit 210, image forming unit 220, and data processing unit 230)) according to a first aspect of some embodiments includes a layer thickness identifying unit (262) and a characteristic position identifying unit (263). The layer thickness identifying unit identifies the layer thickness in the A-scan direction of a predetermined layer region at a measurement site based on OCT data of the subject's eye (E). The characteristic position identifying unit identifies a characteristic position of a change in layer thickness in a direction intersecting the A-scan direction (B-scan direction) based on the layer thickness identified by the layer thickness identifying unit.

[0286] According to this aspect, since the characteristic position of the amount of change in layer thickness at the measurement site of the subject's eye is identified, it is possible to identify the change in the morphology of the tissue of the subject's eye with high accuracy. Furthermore, it is possible to observe the change in the morphology of the tissue of the subject's eye in detail over a wide range, regardless of the measurement range such as the imaging angle of view.

[0287] An ophthalmological information processing device according to a second aspect of some embodiments is the first aspect and includes a risk determining unit (265) that determines a risk of disease based on an amount of change in layer thickness at a characteristic position.

[0288] According to this aspect, the risk of disease is determined based on the amount of change in layer thickness at the identified characteristic position, so it is possible to determine the risk of disease even when the morphological changes specific to the disease are not significant, which can contribute to early detection and early treatment of the disease.

[0289] In an ophthalmological information processing device according to a third aspect of some embodiments, in a second aspect, the risk assessment unit assesses the risk of disease based on risk assessment information (212A) in which information representing the risk of disease is pre-associated with each of a plurality of change amounts.

[0290] According to this aspect, the risk of disease can be determined according to the relationship between a predetermined amount of change and information representing the risk of disease, making it possible to determine the risk of disease with high accuracy even when the morphological changes specific to the disease are not significant.

[0291] In the ophthalmology information processing device according to a fourth aspect of some embodiments, in the second or third aspect, the disease includes central serous chorioretinopathy (CSC).

[0292] According to such an embodiment, it becomes possible to determine the risk of CSC even when the morphological changes specific to CSC are not significant, which can contribute to the early detection and early treatment of CSC.

[0293] An ophthalmological information processing device according to a fifth aspect of some embodiments, in any of the first to fourth aspects, includes a display control unit (211A) that causes a display means (display unit 240A) to display a layer thickness change amount profile that represents the change amount of layer thickness along the above-mentioned intersecting direction, and the display control unit causes the display means to display information indicating a position corresponding to a characteristic position in the layer thickness change amount profile.

[0294] According to this aspect, information indicating positions corresponding to characteristic positions in the layer thickness change profile is displayed on the display means, so that it becomes possible to continuously observe in detail changes in morphology as areas that require future attention.

[0295] In the ophthalmologic information processing device according to a sixth aspect of some embodiments, in the fifth aspect, the display control unit causes the display means to display information indicating the amount of change at a characteristic position in the layer thickness change amount profile.

[0296] According to this aspect, the amount of change at a characteristic position in the layer thickness change amount profile can be visually recognized, so that it becomes possible to continuously observe in detail the change in morphology of a region that should be noted in the future.

[0297] In an ophthalmological information processing device according to a seventh aspect of some embodiments, in the fifth or sixth aspect, the display control unit causes the display means to display information representing a gradient corresponding to the amount of change in layer thickness at a characteristic position.

[0298] According to this embodiment, the amount of change in the layer thickness can be easily grasped.

[0299] In an ophthalmologic information processing device according to an eighth aspect of some embodiments, in any of the fifth to seventh aspects, the display control unit causes the display means to display the layer thickness change profile and a tomographic image formed based on the OCT data, and causes the display means to display information indicating a position corresponding to a characteristic position in the tomographic image.

[0300] According to this embodiment, it becomes possible to continuously observe in detail the changes in morphology of areas that require future attention.

[0301] An ophthalmologic information processing device according to a ninth aspect of some embodiments is the eighth aspect, and includes a shape correction unit (300) that performs shape correction on OCT data or a tomographic image. The display control unit causes the display means to display a corrected tomographic image (tomographic image IMG4) formed based on the OCT data that has been shape corrected by the shape correction unit, or a tomographic image that has been shape corrected by the shape correction unit.

[0302] According to such an embodiment, for example, a doctor can visually explain to a patient areas suspected of disease as characteristic locations, and it becomes easier for the doctor to consider treatment or surgical strategies.

[0303] An ophthalmologic information processing device according to a tenth aspect of some embodiments is in any of the first to eighth aspects, and includes an actual shape correction unit (300) that performs actual shape correction on the OCT data. The layer thickness determination unit determines the layer thickness in the A-scan direction of a predetermined layer region based on the OCT data that has been subjected to actual shape correction by the actual shape correction unit.

[0304] In this embodiment, the OCT data may be two-dimensional OCT data or three-dimensional OCT data. According to this embodiment, a layer thickness analysis can be performed on the layer region that has undergone actual shape correction to identify the characteristic position. This allows the characteristic position to be accurately identified in accordance with the shape of the eyeball of the subject's eye.

[0305] In an ophthalmologic information processing device according to an eleventh aspect of some embodiments, in any of the first to tenth aspects, the characteristic position identification unit identifies the characteristic position based on the difference in layer thickness between adjacent A-lines in the intersecting direction and the scan angle for each A-line centered on the scan center position of the OCT scan in the test eye.

[0306] According to this aspect, it is possible to identify the characteristic position of the amount of change in layer thickness with high accuracy.

[0307] In an ophthalmological information processing device according to a twelfth aspect of some embodiments, in an eleventh aspect, the characteristic position identification unit includes a smoothing unit (moving average processing unit 2631) that smooths the layer thicknesses of multiple A-lines adjacent in the intersecting direction in the intersecting direction, and identifies a characteristic position of the amount of change in layer thickness based on the layer thicknesses of the multiple A-lines smoothed by the smoothing unit.

[0308] According to this aspect, stepped layer thickness profile data is smoothed, and characteristic positions can be identified with good reproducibility from the layer thickness profile data smoothed in the intersecting direction.

[0309] In an ophthalmologic information processing device according to a thirteenth aspect of some embodiments, in the twelfth aspect, the smoothing unit sequentially calculates a moving average of the layer thicknesses of a plurality of A-lines within a range of a predetermined scan angle adjacent to the above-mentioned intersecting direction.

[0310] According to this aspect, a simple moving average process is used to smooth out the stepped layer thickness profile data, and characteristic positions can be identified with good reproducibility from the layer thickness profile data smoothed in the intersecting direction.

[0311] In the ophthalmologic information processing device according to a fourteenth aspect of some embodiments, in any of the first to thirteenth aspects, the characteristic position is a position showing a maximum value or a local maximum value of the amount of change in layer thickness.

[0312] According to this aspect, the position showing the maximum or local maximum value of the amount of change in layer thickness at the measurement site of the subject's eye is identified as the characteristic position, so that the change in the morphology of the tissue of the subject's eye can be identified with high accuracy. Furthermore, regardless of the measurement range such as the imaging angle of view, the change in the morphology of the tissue of the subject's eye can be observed in detail over a wide range.

[0313] In the ophthalmological information processing device according to a fifteenth aspect of some embodiments, in any of the first to fourteenth aspects, the predetermined layer region is the choroid.

[0314] According to this aspect, since the characteristic position of the amount of change in the choroidal layer thickness is identified, it is possible to identify the change in the choroidal morphology with high accuracy. Furthermore, it is possible to observe the change in the choroidal morphology in detail over a wide range, regardless of the measurement range such as the imaging angle of view.

[0315] An ophthalmic device according to a 16th aspect of some embodiments includes an optical scanner (42) and an OCT optical system (an optical system from the OCT unit 100 to the objective lens 22) that acquires OCT data by projecting measurement light (LS) deflected by the optical scanner onto the subject's eye, and an ophthalmic information processing device according to any one of the 1st to 15th aspects.

[0316] According to this aspect, it is possible to provide an ophthalmic apparatus that can identify changes in the morphology of tissues of an examinee's eye with high accuracy, and also to provide an ophthalmic apparatus that can observe changes in the morphology of tissues of an examinee's eye in detail over a wide range, regardless of the measurement range such as the imaging angle of view.

[0317] An ophthalmologic information processing method according to a seventeenth aspect of some embodiments includes a layer thickness specifying step and a feature position specifying step. The layer thickness specifying step specifies a layer thickness in an A-scan direction of a predetermined layer region at a measurement site based on OCT data of the subject's eye (E). The feature position specifying step specifies a feature position of a change in layer thickness in a direction intersecting the A-scan direction (B-scan direction) based on the layer thickness specified in the layer thickness specifying step.

[0318] According to this aspect, since the characteristic position of the amount of change in layer thickness at the measurement site of the subject's eye is identified, it is possible to identify the change in the morphology of the tissue of the subject's eye with high accuracy. Furthermore, it is possible to observe the change in the morphology of the tissue of the subject's eye in detail over a wide range, regardless of the measurement range such as the imaging angle of view.

[0319] A program according to an eighteenth aspect of some embodiments causes a computer to execute each step of the ophthalmologic information processing method of the seventeenth aspect.

[0320] According to this aspect, it is possible to provide a program that can identify changes in the morphology of tissues of an examinee's eye with high accuracy, and also to provide a program that can observe changes in the morphology of tissues of an examinee's eye in detail over a wide range, regardless of the measurement range such as the imaging angle of view.

[0321] The embodiment described above is merely an example of the present invention. Those who wish to implement the present invention may freely make modifications (omissions, substitutions, additions, etc.) within the scope of the gist of the present invention.

[0322] In some embodiments, a program for causing a computer to execute the ophthalmologic information processing method is stored in the storage unit 212. Such a program may be stored in any computer-readable recording medium. The recording medium may be an electronic medium that utilizes magnetism, light, magneto-optical technology, semiconductors, or the like. Typically, the recording medium is a magnetic tape, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, a solid-state drive, or the like. [Explanation of symbols]

[0323] 1 Ophthalmology equipment 2 Fundus camera unit 100 OCT units 210 Control Unit 211 Main control unit 211A Display control unit 212 Storage section 212A Risk Characterization Information 220 Image forming unit 230, 230a Data processing unit 250 Alignment processing section 260 Risk Assessment Processing Unit 261 Layer area identification part 262 Layer thickness identification part 263 Feature Location Identification Unit 2631 Moving average processing unit 2632 Maximum value specification part 264 Layer Thickness Variation Profile Generation Unit 265 Risk Assessment Department 300 Actual shape correction unit 310 Location identification part 320 Position conversion unit 330 Interpolation section E. Examined eye Ef fundus LS measurement light

Claims

1. a layer thickness specifying step in which one or more processors specify a layer thickness in an A-scan direction of a predetermined layer region at the measurement site based on OCT data of the subject's eye; a feature position specifying step of specifying, by the one or more processors, a feature position of a change in the layer thickness in a direction intersecting the A-scan direction based on the layer thickness specified in the layer thickness specifying step; a risk determination step in which the one or more processors determine a risk of disease based on the amount of change in the feature location; Including, An ophthalmologic information processing method, wherein the risk assessment step assesses the risk of the disease based on risk assessment information in which information representing the risk of the disease is previously associated with each of a plurality of change amounts.

2. The disease includes central serous chorioretinopathy 2. The ophthalmologic information processing method according to claim 1.

3. a layer thickness specifying step in which one or more processors specify a layer thickness in an A-scan direction of a predetermined layer region at the measurement site based on OCT data of the subject's eye; a feature position specifying step of specifying, by the one or more processors, a feature position of a change in the layer thickness in a direction intersecting the A-scan direction based on the layer thickness specified in the layer thickness specifying step; a display control step in which the one or more processors display a layer thickness variation profile representing the variation of the layer thickness along the cross direction on a display means; Including, The ophthalmologic information processing method, wherein the display control step causes the display means to display information indicating a position corresponding to the characteristic position in the layer thickness variation profile.

4. The display control step displays information indicating the amount of change at the characteristic position in the layer thickness variation profile on the display means.

4. The ophthalmologic information processing method according to claim 3.

5. The display control step causes the display means to display information representing a gradient corresponding to the amount of change in the layer thickness at the characteristic position.

5. The ophthalmologic information processing method according to claim 3 or 4.

6. The display control step causes the display means to display the layer thickness change amount profile and a tomographic image formed based on the OCT data, and causes the display means to display information indicating a position corresponding to the characteristic position in the tomographic image.

6. The ophthalmologic information processing method according to claim 3, wherein the ophthalmologic information processing method is a method for processing ophthalmologic information.

7. a shape correction step in which the one or more processors perform shape correction on the OCT data or the tomographic image; The display control step displays, on the display means, a corrected tomographic image formed based on the OCT data that has been subjected to the actual shape correction in the actual shape correction step, or the tomographic image that has been subjected to the actual shape correction in the actual shape correction step.

7. The ophthalmologic information processing method according to claim 6.

8. a layer thickness specifying step in which one or more processors specify a layer thickness in an A-scan direction of a predetermined layer region at the measurement site based on OCT data of the subject's eye; a feature position specifying step of specifying, by the one or more processors, a feature position of a change in the layer thickness in a direction intersecting the A-scan direction based on the layer thickness specified in the layer thickness specifying step; a shape correction step in which the one or more processors perform shape correction on the OCT data; Including, The layer thickness specifying step specifies a layer thickness in the A-scan direction of the predetermined layer region based on the OCT data that has been subjected to actual shape correction in the actual shape correction step.

9. The feature position specifying step specifies the feature position based on a difference in the layer thickness between A-lines adjacent in the crossing direction and a scan angle for each A-line centered on a scan center position of an OCT scan of the subject's eye.

9. The ophthalmologic information processing method according to claim 1, wherein the ophthalmologic information processing method is a method for processing ophthalmologic information.

10. a layer thickness specifying step in which one or more processors specify a layer thickness in an A-scan direction of a predetermined layer region at the measurement site based on OCT data of the subject's eye; a feature position specifying step of specifying, by the one or more processors, a feature position of a change in the layer thickness in a direction intersecting the A-scan direction based on the layer thickness specified in the layer thickness specifying step; Including, The feature location step includes: a smoothing step in which the one or more processors smooth the layer thicknesses of a plurality of A-lines adjacent in the cross direction in the cross direction; An ophthalmologic information processing method for identifying the characteristic position based on the difference in layer thickness of the plurality of A-lines smoothed in the smoothing step and the scan angle for each A-line centered on the scan center position of the OCT scan of the test eye.

11. The smoothing step sequentially obtains a moving average of the layer thicknesses of a plurality of A-lines in a range of a predetermined scan angle adjacent to each other in the cross direction. The ophthalmologic information processing method according to claim 10 .

12. The characteristic position is a position that indicates a maximum value or a local maximum value of the amount of change. The ophthalmologic information processing method according to any one of claims 1 to 11.

13. The predetermined layer region is the choroid. The ophthalmologic information processing method according to any one of claims 1 to 12.

14. A program that causes a computer to execute each step of the ophthalmologic information processing method according to any one of claims 1 to 13.

Images