Ophthalmologic image processing device and ophthalmologic image processing program

Abstract

To solve the problem that it is difficult to determine whether or not an acquisition position for an OCT tomographic image has been adjusted to a desired position.SOLUTION: An ophthalmologic image processing device includes: image acquisition means for acquiring an OCT tomographic image and an ocular fundus front image of an image to be examined; display control means for displaying the acquired OCT tomographic image and ocular fundus front image, and displaying a first index at a position of the OCT tomographic image on the ocular fundus front image; and determination means for determining whether or not there exists a predetermined site or a lesion candidate in the acquired OCT tomographic image. If the determination means determines that there exists a predetermined site of the image to be examined or a lesion candidate in the OCT tomographic image, the display control means executes control to display a second index showing that there exists the predetermined site or the lesion candidate in the OCT tomographic image in at least one of a peripheral part of the OCT tomographic image, the image of the ocular fundus front image, and a peripheral part of the ocular fundus front image.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] This invention relates to an ophthalmic image processing device and an ophthalmic image processing program. [Background technology]

[0002] Optical coherence tomography (OCT), which utilizes optical interference, can obtain high-resolution cross-sectional images of samples and is becoming an indispensable device in ophthalmology, particularly in specialized retinal clinics. It is also used in applications beyond ophthalmology, such as endoscopy. Hereafter, this will be referred to as an OCT device.

[0003] OCT devices are configured to allow changes in scan position and range so that OCT tomographic images of the target area can be acquired. Generally, the examiner sets the acquisition position of the OCT tomographic image while confirming the acquisition position of the image of the eye under examination displayed on the frontal image. Patent Document 1 discloses a technique that enables fine adjustment of the scan position even when the fixation of the eye under examination is not stable. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-19906 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, with the technology described in Patent Document 1, it is difficult to immediately determine whether the scan position has been adjusted to the desired location. Even if the examiner is highly proficient in the operation, it is difficult to shorten the time required for confirmation in order to reduce the burden on the patient. Furthermore, for examiners with low proficiency, not only is the operation unfamiliar and time-consuming, but it is also difficult to instantly judge whether the displayed OCT tomographic image has been adjusted to the desired location.

[0006] The present invention aims to solve the above-mentioned problems and provide an ophthalmic image processing device and an ophthalmic image processing program that allows the examiner to easily and instantly confirm that the appropriate scan position has been set when setting the acquisition position of the OCT tomography image of the eye under examination, while confirming the acquisition position of the OCT tomography image displayed on the frontal image. [Means for solving the problem]

[0007] The first embodiment of the present invention is Image acquisition means for acquiring OCT tomographic images and frontal images of the eye under examination, The system includes a display control means that displays the acquired OCT tomographic image and the frontal view of the fundus, and displays a first indicator at the position of the OCT tomographic image on the frontal view of the fundus, This ophthalmic image processing device controls the display control means to display a second indicator indicating the presence of a predetermined area or candidate lesion in the OCT tomography image, either on or in the peripheral area of ​​at least one of the OCT tomography image and the frontal fundus image, when a predetermined area or candidate lesion of the eye under examination is present in the displayed OCT tomography image.

[0008] A second embodiment of the present invention is Image acquisition step to obtain OCT tomographic images and frontal images of the eye under examination, The system includes a display control step of displaying the acquired OCT tomographic image and the frontal fundus image, and displaying a first indicator at the position of the OCT tomographic image on the frontal fundus image, This ophthalmic image processing program controls the display control step to display a second indicator indicating the presence of a predetermined area or candidate lesion in the OCT tomography image, either on or in the peripheral area of ​​at least one of the OCT tomography image and the frontal fundus image, if a predetermined area or candidate lesion of the eye under examination is present in the displayed OCT tomography image. [Effects of the Invention]

[0009] According to the present invention, when a examiner sets the acquisition position of a captured image of the eye to be examined displayed on a front image, it becomes possible to easily and instantaneously confirm that the acquisition position of the captured image has been set to an appropriate scan position. At the same time, since the time required for the confirmation can be shortened, it is possible to reduce the burden on the subject.

Brief Description of the Drawings

[0010] [Figure 1] It is an overall configuration diagram of this embodiment. [Figure 2] It is an explanatory diagram of the measurement optical system of this embodiment. [Figure 3] It is an explanatory diagram of scanning. [Figure 4] It is an example of a patient selection screen. [Figure 5] It is an example of a captured image screen before the start of inspection. [Figure 6] It is an example of a captured image screen in the Macula3D scan mode. [Figure 7] It is an example of moving the scan range. [Figure 8] It is an operation flow diagram of the examiner. [Figure 9] It is an explanatory diagram of the scanning line position for part detection. [Figure 10] It is an explanatory diagram of part detection using layer thickness. [Figure 11] It is an example of an OCT tomographic image obtained by a scanning line for part detection. [Figure 12] It is an example of the second display form on the captured image screen. [Figure 13] It is an example of moving the scan position within the scan range. [Figure 14] It is an example of a captured image confirmation screen in the Macula3D scan mode. [Figure 15] It is an example of the second display form on the captured image confirmation screen. [Figure 16] It is a modified example of the captured image confirmation screen. [Figure 17] It is another example of the second display form on the captured image confirmation screen. [Modes for carrying out the invention]

[0011] The present invention will be described in detail based on the illustrated embodiments.

[0012] <Example 1> (Main unit configuration) Figure 1 is a side view of the ophthalmic imaging device in this embodiment.

[0013] 100 is a head unit having a measurement optical system for acquiring anterior segment images, SLO fundus images of the eye under examination, and OCT tomographic images. 101 is a stage unit that allows the head unit 100 to move forward, backward, left, and right. 102 is a base unit that incorporates the spectrometer described later.

[0014] 103 is a control unit that controls the stage unit 101, controls alignment movements, constructs OCT tomographic images, controls display, and performs analysis, and is, for example, a personal computer. 104 is a storage unit that stores, for example, programs for OCT tomographic image acquisition, patient information, imaging data, and statistical information such as a normal eye database.

[0015] 105 is an input unit that gives instructions to the computer, and specifically consists of a keyboard and a mouse. 106 is a display unit such as a monitor. The display control unit (not shown) of the control unit 103 functions as a display control means that controls the display of images and other content shown on the display unit 106.

[0016] (Configuration of the measurement optical system and spectrometer) The configuration of the measurement optical system and spectrometer of this embodiment will be explained with reference to Figure 2.

[0017] The measurement optical system of the head unit 100 will now be described.

[0018] An objective lens 201 is positioned opposite the eye under examination 200, and a first dichroic mirror 202 and a second dichroic mirror 203 are positioned on its optical axis. These dichroic mirrors branch the optical path 250 of the OCT optical system, the optical path 251 for the SLO optical system and fixation light which serve both for observing the eye under examination and acquiring SLO fundus images, and the optical path 252 for anterior eye observation, according to wavelength band.

[0019] The SLO optical system and the optical path 251 for the fixation lamp include an SLO scanning means 204, lenses 205 and 206, a mirror 207, a third dichroic mirror 208, a photodiode 209, an SLO light source 210, and a fixation lamp 211. The mirror 207 is a prism with a perforated or hollow mirror deposited on it, which separates the illumination light from the SLO light source 210 from the reflected light from the eye under examination. The third dichroic mirror 208 separates the light into wavelength bands for the optical paths to the SLO light source 210 and the fixation lamp 211.

[0020] The SLO scanning means 204 scans the fundus of the eye under examination 200 with light emitted from the SLO light source 210 and the fixation lamp 211, and consists of an X scanner that scans in the X direction and a Y scanner that scans in the Y direction. In this embodiment, the X scanner is made of a polygon mirror because high-speed scanning is required, and the Y scanner is made of a galvanometer mirror.

[0021] Lens 205 is driven by a motor (not shown) for focusing the SLO optical system and the fixation lamp 211. The SLO light source 210 generates light with a wavelength of around 780 nm. The photodiode 209 detects the reflected light from the eye under examination. The fixation lamp 211 generates visible light to encourage the subject to fixate.

[0022] Light emitted from the SLO light source 210 is reflected by the third dichroic mirror 208, passes through the mirror 207, then through lenses 206 and 205, and the fundus of the eye under examination 200 is scanned by the SLO scanning means 204. The light returned from the eye under examination 200 returns along the same path as the projected light, is reflected by the mirror 207, and is guided to the photodiode 209, where an SLO fundus image is obtained.

[0023] Light emitted from the fixation lamp 211 passes through the third dichroic mirror 208 and mirror 207, then through lenses 206 and 205, and the fundus of the eye under examination 200 is scanned by the SLO scanning means 204. At this time, by flashing the fixation lamp 211 in accordance with the movement of the SLO scanning means 204, any shape can be created at any position on the eye under examination 200, encouraging the subject to fixate.

[0024] The optical path 252 for anterior eye observation includes lenses 212 and 213, a split prism 214, and a CCD 215 for anterior segment observation that detects infrared light. This CCD 215 is sensitive to the wavelength of the anterior eye observation illumination light (not shown), specifically around 970 nm. The split prism 214 is positioned conjugate to the pupil of the eye under examination 200, and can detect the distance of the measurement optical system 100 to the eye under examination 200 in the Z direction (anterior-posterior direction) as a split image of the anterior segment.

[0025] As mentioned above, the optical path 250 of the OCT optical system constitutes the OCT optical system and is for acquiring OCT tomographic images of the fundus of the eye under examination 200. More specifically, it is for obtaining interference signals to form the tomographic image. 216 is an XY scanner for scanning the fundus of the eye under examination 200 with light. The XY scanner 216 is illustrated as a single mirror, but it is a galvanometer mirror that performs scanning in the XY two-axis direction.

[0026] 217 and 218 are lenses, of which lens 217 is driven by a motor (not shown) to focus the light from the OCT light source 220, which is emitted from the fiber 224 connected to the optical coupler 219, onto the eye under examination 200. This focusing causes the light returned from the eye under examination 200 to simultaneously be imaged as a spot at the tip of the fiber 224.

[0027] Next, we will describe the optical path from the OCT light source 220, the reference optical system, and the spectrometer configuration within the measurement optical system. 220 is the OCT light source, 221 is the reference mirror, 222 is the dispersion compensation glass, 223 is the lens, 219 is the optical coupler, 224 to 227 are single-mode optical fibers connected to the optical coupler and integrated together, and 230 is the spectrometer.

[0028] These components constitute a Michelson interferometer. Light emitted from the OCT light source 220 passes through the optical fiber 225 and is split via the optical coupler 219 into measurement light on the optical fiber 224 side and reference light on the optical fiber 226 side. The measurement light passes through the aforementioned OCT optical system path and illuminates the eye under observation 200, and through reflection and scattering by the eye under observation, it reaches the optical coupler 219 via the same optical path.

[0029] Meanwhile, the reference light reaches the reference mirror 221 via the optical fiber 226, lens 223, and dispersion-compensating glass 222 inserted to match the dispersion of the measurement light and the reference light, where it is reflected. It then returns to the return light coupler 219 along the same optical path.

[0030] The optical coupler 219 combines the measurement light and the reference light to produce interference light. Interference occurs when the optical path lengths of the measurement light and the reference light are approximately the same. The reference mirror 221 is held in an adjustable manner in the optical axis direction by a motor and drive mechanism (not shown), allowing the optical path length of the reference light to be adjusted to match the optical path length of the measurement light, which varies depending on the eye under examination 200. The interference light is led to the spectrometer 230 via the optical fiber 227.

[0031] Furthermore, 228 is a polarization adjustment unit on the measurement light side provided in optical fiber 224. 229 is a polarization adjustment unit on the reference light side provided in optical fiber 226. These polarization adjustment units have several loop-shaped sections around the optical fiber. By rotating these loop-shaped sections around the longitudinal direction of the fiber, twisting is applied to the fiber, making it possible to adjust and match the polarization states of the measurement light and the reference light, respectively.

[0032] The spectrometer 230 consists of lenses 232 and 234, a diffraction grating 233, and a line sensor 231. Interfering light emitted from the optical fiber 227 is converted into parallel light via lens 234, then dispersed by the diffraction grating 233, and finally imaged onto the line sensor 231 by lens 232.

[0033] Next, we will describe the surroundings of the OCT light source 220. The OCT light source 220 is a typical low-coherent light source, an SLD (Super Luminescent Diode). Its central wavelength is 855 nm, and its wavelength bandwidth is approximately 100 nm. Here, bandwidth is an important parameter because it affects the resolution in the optical axis direction of the resulting tomographic image.

[0034] While an SLD was chosen as the light source here, any light source that emits low-coherent light, such as ASE (Amplified Spontaneous Emission), can be used. Considering that the measurement will involve the eye, near-infrared light is suitable as the central wavelength. Furthermore, since the central wavelength affects the lateral resolution of the resulting tomographic image, it is desirable to use the shortest possible wavelength. For both reasons, a central wavelength of 855 nm was chosen.

[0035] In this embodiment, a Michelson interferometer was used as the interferometer, but a Mach-Zehnder interferometer may also be used. Depending on the difference in light intensity between the measurement light and the reference light, it is desirable to use a Mach-Zehnder interferometer when the difference in light intensity is large, and a Michelson interferometer when the difference in light intensity is relatively small. With the above configuration, a tomographic image of the eye under examination can be obtained, and a high-contrast SLO fundus image of the eye under examination can be obtained even with near-infrared light.

[0036] (Method for acquiring tomographic images) This section describes a method for acquiring optical coherence tomography (OCT) images using an ophthalmic imaging device. The ophthalmic imaging device can acquire tomographic images of a predetermined area of ​​the eye under examination 200 by controlling the XY scanner 216. Here, the trajectory of the tomographic image acquisition light scanning within the eye under examination is called the scan pattern. Examples of scan patterns include a cross scan, which scans vertically and horizontally in a cross shape centered on a single point, and a 3D scan, which scans the entire area to fill it in and obtain a 3D OCT image as a result. A cross scan is suitable when detailed observation of a specific area is desired, while a 3D scan is suitable when observing the layer structure and thickness of the entire retina.

[0037] Figure 3 illustrates the imaging method when performing a 3D scan. First, at the scanning point A11, the interference light spectrally separated by the diffraction grating 233 is imaged by the line sensor 231 to obtain a signal in the depth (Z) direction. After converting the spectral distribution on the line sensor 231 into a wavenumber distribution, the intensity distribution in the depth (Z) axis direction in the subject space can be obtained by performing a Fast Fourier Transform (FFT). This is called an A-scan image, following the terminology used in time-domain OCT, which was developed in the early days of OCT.

[0038] By shifting the scanning position in the X direction and performing scans from A11 to A1m, a two-dimensional tomographic image can be obtained by arranging multiple A-scan images. This scan is called a B-scan, and the resulting tomographic image is called a B-scan image. The scanning direction of the B-scan is called the main scanning direction. By shifting the scanning position in the Y direction and performing a B-scan from B1 to Bn, a three-dimensional OCT image can be obtained. The direction from B1 to Bn, that is, the direction perpendicular to the main scanning direction, is called the sub-scan direction.

[0039] By displaying multiple B-scan images, or a 3D OCT image constructed from multiple B-scan images, on the display unit 106, the examiner can diagnose the eye under examination. Here, an example is shown in which a 3D OCT image is obtained by acquiring multiple B-scan images in the X direction with the scanning position shifted in the Y direction, but a 3D OCT image may also be obtained by acquiring multiple B-scan images in the Y direction with the scanning position shifted in the Y direction.

[0040] In the case of a cross scan, the B-scan image is acquired with the primary scanning direction of the B-scan set to the horizontal direction, and then the B-scan image is acquired with the direction perpendicular to the primary scanning direction of the B-scan set to the vertical direction. The acquisition order is not limited to this; the vertical B-scan image may be acquired first, followed by the horizontal B-scan image.

[0041] (Examiner operation flow) Next, we will explain a typical examiner operation flow using Figures 4-8.

[0042] First, in step S100 of the operation flow in Figure 8, patient information input, the examiner inputs the patient information of the subject using the patient screen shown in Figure 4, which is displayed on the display unit 106 by the control unit 103, and the input unit 105. The patient screen (Figure 4) displayed by pressing the patient tab (button) 401 shown in Figure 5 has an input area 405 in the upper section where text boxes for entering patient information are lined up, and a patient list 404 that displays a list of patients in the lower section. When the examiner uses the input unit 105 to enter patient information into the input area 405, the patient list 404 displays patients that match the entered patient information, and when the input is updated, the display content of the patient list 404 is updated accordingly, and is used to identify the desired patient. To select a registered patient, simply click on the patient you want to select on the patient list 404, and to register a new patient, click the Add button 406 provided in the input area 405.

[0043] In step S101, the examiner chooses whether or not to perform imaging. If imaging is performed, the examiner presses the OCT imaging tab (button) 402 shown in Figure 4 and proceeds to step S102.

[0044] In step S102, the examiner begins preparing for imaging using the imaging screen (Figure 5) for imaging the eye 200 under examination. First, the examiner adjusts the height of the chin rest using the chin rest vertical position adjustment switch 530 so that the height of the eye 200 under examination is approximately the same as the eye height mark provided on the frame of the chin rest. Next, when the examiner presses R or L on the left / right eye switching switch 501 to select the eye to be measured, the control unit 103 controls the optical head 100 to move to the initial position of either the left or right eye, which is the eye to be measured as indicated by the pressed button. After the movement is complete, if part of the pupil is not visible in the anterior segment moving image 532 of the eye 200 under examination, the examiner adjusts the vertical and horizontal position of the optical head 100 by operating the anterior-posterior position adjustment switch 531 of the optical head 100 and the switch 533 on the displayed anterior segment moving image 532 so that part of the pupil is imaged in the anterior segment observation system.

[0045] Next, in step S103, the examiner selects the examination set they want to perform on the imaging screen. An examination set is a group of information related to an examination protocol, in which information such as scanning modes and other measurement conditions according to the purpose of the examination is associated and stored. The examiner selects the name of the examination set associated with that protocol from the Examination Set pull-down menu 502.

[0046] Figure 5 shows an example of the capture screen when, for example, the examiner selects an examination set named Custom1. Examination set Custom1 is associated with Macula3D as a scan mode for scanning the macula in two dimensions. On the capture screen, the Macula3D icon in icon group 503 lights up, the scan mode name is displayed in caption 504, and the scanning range of the selected scan mode is displayed in the SLO preview image 505, which is a frontal image of the fundus. At the same time, the fixation lamp icon group 506 displays the selection status of the fixation lamp for the macula, and the examiner can confirm that the 1mm internal fixation lamp has been selected.

[0047] In step S104, the inspection is started. When the examiner presses the Start button 507, the inspection begins and auto-alignment starts. During the auto-alignment process, various adjustments are made to the stage unit 102 in preparation for tomographic image acquisition. The Start button 507 is then updated to display as a Stop button, which instructs the end of the inspection. Pressing the Stop button will initiate an emergency stop in case of an abnormality.

[0048] First, the analysis unit of the control unit 103 analyzes the frames of the anterior segment moving image 532 sequentially acquired by the anterior eye observation optical system of the measurement optical system of the optical head 100, and controls a motor (not shown) to adjust the position of the stage unit 101 in the XY direction so that the pupil center of the eye under examination 200 is brought closer to the center of the anterior segment moving image 532 which coincides with the optical axis of the measurement optical system. Then, for example, based on the spacing of the corneal reflection images of multiple anterior segment illumination light sources (not shown), the optical axis (Z) direction of the measurement optical system and the eye under examination 200 is adjusted. The adjustments of both can be performed alternately and continuously, or in parallel. When the position of the measurement optical system is within a predetermined tolerance range, the control unit 103 instructs the SLO light source 210 to emit only infrared light and drives the SLO scanning means 204 to enable the acquisition of the SLO preview image 505. At the same time as the acquisition of the SLO preview image begins, the OCT scan is started.

[0049] When rough auto-alignment adjustment is performed, the edge of the pupil of the eye being examined in the anterior segment moving image 532 becomes sharper, and the pupil, which has been split by the split prism 214 provided on the optical path 252 for anterior segment observation as described above, becomes clearly observable. The control unit 103 controls a motor (not shown) to adjust the position of the optical axis of the measurement optical system in the XY direction, bringing it closer to the center of the anterior segment moving image 532, and adjusts the position of the measurement optical system in the Z direction so that the amount of split in the split pupil becomes zero. Once it is confirmed that the positional deviation as a result of the above fine auto-alignment has fallen within a predetermined range, the system moves on to the next step S105, which is the adjustment of the imaging position.

[0050] Figure 6 shows an example of the capture screen when the scan mode of Macula3D is selected and the examination is started. When the examination starts, SLO images, which are frontal images of the fundus, are acquired sequentially, and as shown in Figure 6, the SLO preview image (the latest SLO image acquired sequentially and displayed as a video) 505 is displayed on the capture screen. Markers 601 and 602 indicating the OCT scan range and the internal fixation light position 603 are displayed on the SLO preview image 505 (on the frontal image of the fundus). The solid arrows 610, 611, and 612 parallel to markers 601 and 602 are all first indicators indicating the tomographic image acquisition position in the main scanning direction, and the dotted arrow 620 perpendicular to the solid arrow 610 is a first indicator indicating the tomographic image acquisition position in the sub-scanning direction.

[0051] Furthermore, images 510-512 and 520 are OCT preview tomographic images (OCT tomographic motion images) that sequentially display OCT tomographic images acquired sequentially at each position of the first indicator. Specifically, OCT preview tomographic images 510 and 520 are OCT tomographic images acquired sequentially at the position of the solid arrow 610 (horizontal direction) and the dotted arrow 620 (vertical direction), respectively. Also, OCT preview tomographic images 511 and 512 are OCT tomographic images acquired and displayed sequentially at the position of the solid arrow 611 (horizontal direction) and the solid arrow 612 (horizontal direction), respectively. Note that 521 and 522 are display areas.

[0052] In this case, to make it easier to identify the correspondence between the first indicator (arrow indicating the tomographic image acquisition position) and the OCT preview tomographic image acquired at that position, the display format of the first indicator and the display format of the frame of the display area for the OCT preview tomographic image can be matched. That is, if there are multiple sets of the first indicator and the corresponding display area frame, the display can be controlled so that the display format of each set of the first indicator and the corresponding display area frame is different. For example, in Figure 6, the display format of the frames of the display areas for OCT preview tomographic images 510, 511, and 512 is displayed as solid lines corresponding to the solid line arrows 610, 611, and 612, which are the horizontal first indicators representing the acquisition position of each OCT preview tomographic image, and the frame of the display area for OCT preview tomographic image 520 is displayed as a dotted line corresponding to the dotted line arrow 620, which represents the acquisition position of the OCT preview tomographic image. However, each set of the first indicator and the corresponding display area frame may be displayed in the same color, and each set may be displayed in a different color from each other.

[0053] Once it is confirmed that the SLO preview image 505 is appropriate, autofocus adjustment is started. In this embodiment, a so-called "hill-climbing AF" method is used to determine the focus position by monitoring the received light signal while driving the lens 205, taking advantage of the characteristic of confocal SLO where the output of the SLO light source 210, i.e., the received light signal, is maximized when the fundus is correctly focused. Of course, this adjustment may also use the sharpness of the image rather than the magnitude of the received light signal. Furthermore, the lens 217 of the OCT optical system may be linked at this point to perform focus adjustment of the OCT optical system in parallel. Alternatively, focus adjustment may be performed manually, and in that case, it may be possible to operate it using a GUI such as a focus adjustment button 640.

[0054] After the focus adjustment of both the SLO and OCT optical systems is completed, an eye movement detection unit (not shown) calculates the movement of the fundus of the eye being examined from the amount of movement of the sequentially acquired SLO images. The control unit 103 gives a drive command to the XY scanner 216, which is the OCT scanning means, to correct this movement and make the OCT measurement light follow. This is what is known as fundus tracking. As a result, the movement of the eye being examined is canceled out in the OCT preview tomographic image, that is, the relative position between the scanning position of the measurement light and the newly acquired frontal image of the fundus of the eye being examined is maintained, so that an OCT preview tomographic image in which the influence of the movement of the eye being examined is eliminated can be obtained. In this state, the control unit 103 accepts the examiner's operation to the reference optical path length adjustment unit 641, and drives the reference mirror 221 according to the received operation to perform the OCT reference optical path length adjustment, and the device adjustment in the preview state is completed.

[0055] During or after the above adjustments are completed, the examiner may make fine adjustments to the imaging position while checking the SLO preview image 505. If these fine adjustments to the imaging position are made during the above adjustments, the adjustment operation may be interrupted, and any necessary adjustments may be made again after the fine adjustments to the imaging position have been made. Currently, the scan mode is Macula3D for scanning the macula in two dimensions, so the internal fixation light position is set to the center of the SLO preview image 505. If the subject maintains sufficient visual acuity and is viewing and fixating on the internal fixation light, the macular region MA will be displayed to coincide with the internal fixation light position 603, as shown in Figure 7(a), and the fovea, which is a depression (concave) in the retina, will be drawn in the central part of the OCT preview tomographic images 510 and 520 in Figure 6, which correspond to the first indicators 610 and 620, which are the central scan lines of the scan range indicated by markers 601 and 602.

[0056] However, in cases of eccentric fixation, where the subject's fixation point is shifted from the fovea due to cataract opacity, vitreous opacity due to bleeding, strabismus, etc., or when visual acuity is lost and the internal fixation light cannot be seen, the fovea is not always depicted in the OCT preview tomographic images 510 and 520, resulting in a state like that shown in Figure 7(b), where the intersection of the first index 610 and 620, which are the central scan lines of the scan range, does not coincide with the foveal MA.

[0057] Since the fovea is the most important part of the fundus that determines maximum visual acuity, it is important to properly confirm or record the foveal tomographic image in the OCT preview during macular examination. Of course, if 3D scanning is selected as the scanning pattern, in terms of recording for diagnostic purposes, even if the foveal tomographic image is not captured during the preview, the vicinity of the fovea will be captured in one of the 3D-OCT tomographic images, so it is not particularly necessary to strictly align the positions of the first indicators 610 and 620, which indicate the central scan line, with the fovea.

[0058] However, in cases where the scanning pattern is such as a cross scan that scans vertically and horizontally in a cross shape around a single point, or a radial scan that scans in multiple directions at predetermined angular intervals around a single point, or even in the case of 3D scanning, when performing a follow-up examination for a previous examination in which fixation was stable and a tomographic image of the fovea was obtained, it is important to capture the fovea in the central tomographic image, and of course, it is best to check that tomographic image during the preview.

[0059] Therefore, if the subject's fixation is misaligned with the fovea, it is desirable to move the position of the imaging area displayed by rectangles 601 and 602 on the SLO preview image 505, for example by dragging with the mouse, as shown in Figure 7(c), to confirm the tomographic image of the fovea. In this embodiment, in order to easily confirm this, that is, to easily determine whether or not the fovea, which is the area of ​​interest, is present in the displayed tomographic image, a GUI is provided that displays the presence confirmation function of the fovea, which is the area of ​​interest, and the confirmation result, as described below.

[0060] First, the function for confirming the presence of the foveal position will be explained. In this embodiment, as shown in Figure 9, the function for confirming the presence of the foveal position will be explained first. In this embodiment, as shown in Figure 9, during the preview, in addition to the four tomographic images obtained from the scan lines at the central indicators 610, 611, 612 and 620 perpendicular to 610, tomographic images obtained from scan lines parallel to the central indicator 610, two above and two below at predetermined intervals, are acquired sequentially, i.e., a total of eight tomographic images, six horizontally and one vertically. As mentioned above, the tomographic image obtained from the scan line at the position of the first indicator is displayed on the measurement screen, but the tomographic images from the scan lines at the two additional positions above and below are not displayed on the screen. A total of five tomographic images, including the tomographic image from the scan line at the position of the first indicator 610, are used to confirm whether the foveal is present in the tomographic image at the central position of the first indicator 610. An example of the confirmation method is shown below.

[0061] First, the analysis unit of the control unit 103 detects the boundary between the pigment epithelium and the internal limiting membrane from each tomographic image, as shown in Figure 10, and smooths it sufficiently. Then, the depth coordinate y of each layer acquired for each A scan RPE , y ILM The total retinal thickness d between these points is calculated, and for each tomographic image, the minimum value d of this smoothed total retinal thickness is determined. minN and d minN The horizontal coordinate position x minN This is obtained. (The method of layer detection and thickness calculation will be explained in the second embodiment, so a detailed explanation is omitted here.) Here, N is 1 to 5 and indicates the tomographic image number, and in the tomographic image of the scan line position corresponding to the first index 610, dmin3 and x min3 is as follows.

[0062] Minimum value d minN When determining the minimum value d, sufficient smoothing is performed to remove extremely small extreme points, and to make the detection more reliable, the minimum value d minN is the average film thickness d ave around the minimum value. Only the extreme points that are lower than the predetermined value may be adopted. If no extreme point is detected in this case, d minN = d ave and x minN = x minM (= the x coordinate at the M-th section where the extreme point is detected) is set.

[0063] When the magnitude relationship of d calculated as above is minN as follows 、 d min3< d minN (N = 1, 2, 4, 5), it is determined that the fovea exists in the tomographic image at the scanning line position corresponding to the first index 610. When x minN ≈ the center position of the screen, it is determined that the fovea exists in the tomographic image at the scanning line position corresponding to the first index 620. Examples of tomographic image groups obtained when the fovea does not exist in the tomographic images at the scanning line positions corresponding to the first indices 610 and 620 are shown in Fig. 11(a), and examples of tomographic image groups obtained when the fovea exists in the tomographic images at the scanning line positions corresponding to the first indices 610 and 620 are shown in Fig. 11(b). In this embodiment, the detection of the fovea in the sub-scanning direction is performed only by comparing d minN . However, it is needless to say that the complementation between scanning lines can be performed from the position information of the scanning lines and d minN to estimate the scanning line number at which d min becomes the minimum, and the presence of the fovea can be confirmed by comparing this with the scanning line number corresponding to the first index 610.

[0064] Next, the GUI when the presence of the fovea is confirmed will be explained using Figure 12. As described above, when the analysis unit confirms the presence of the fovea in the OCT tomographic image of the scan line corresponding to the position of the first indicator 610 and / or 620, the control unit 103 determines that the fovea is present in the OCT tomographic image at the position of the first indicator 610 and / or 620, and displays a second indicator indicating the presence of the fovea in the tomographic image in at least one of the following: the peripheral part of the OCT tomographic images 510 and 520 acquired at the position of the first indicator 610 and / or 620, on the image of the frontal fundus image 505, and the peripheral part of the frontal fundus image. In Figure 12, the second indicator, the ★ mark 540 and 541, which indicates the presence of the fovea in the tomographic image, is displayed in the peripheral part of the OCT tomographic images 510 and 520. Furthermore, this ★ mark, which is the second indicator, may not be displayed if the fovea is not present in the tomographic image in question, and may only be displayed when the fovea becomes present. Alternatively, the display format of the normal indicator, which is displayed even when the fovea is not present, may be changed and displayed as the second indicator. For example, the first indicator, the arrow Horizontal, Vertical, which indicates the acquisition position and direction of the tomographic image, may be changed to display in bold or change the font color when the fovea is present in the tomographic image of the scan line corresponding to the position of the arrow, and this change in display format may be used to display it as the second indicator. Furthermore, the frame of the display area of ​​the OCT tomography image may be changed to a thick frame of a different color than the normal display frame when the fovea is present in the OCT tomography image 510 acquired by the scan line corresponding to the position of the first indicator 610, while the frame of the display area of ​​the OCT tomography image 510 is set to a normal indicator. Similarly, when the fovea is present in the OCT preview tomography image 520 acquired by the scan line corresponding to the position of the arrow 620, which is the first indicator indicating the vertical tomography image acquisition position, the frame of the display area of ​​the OCT preview tomography image 520 may be changed to a thick frame of a different color. In addition, the second indicator may be configured to be switchable between display and hide, and if there are multiple second indicators, each can be switched on and off.

[0065] In any case, the second indicator must not adversely affect the displayed tomographic image itself and must be easily identifiable by the examiner. The display location is preferably the peripheral part of the tomographic image (it may be on the tomographic image itself, but the outermost part is preferable) and / or outside. On the other hand, in the state shown in Figure 12, the first indicators 611 and 612, which indicate the horizontal tomographic image acquisition position, are not located in the predetermined position of the macula. Therefore, the second indicator is not displayed in the display area that displays the OCT preview tomographic images 511 and 512, and remains displayed in the normal display format.

[0066] As described above, the examiner confirms that the fovea, the area of ​​interest, is present in the desired tomographic image, and further, if necessary, visually confirms whether the fovea is normal, before taking the image in step S106. When the examiner presses the Capture button 508 to signal the start of the image acquisition, the image is taken according to the examination set in step S103. In this way, the examiner uses the second indicator to quickly and easily confirm that the fovea can be reliably imaged in the central tomographic image before taking the image. Therefore, in cases where the scanning pattern is, for example, a Cross scan that scans vertically and horizontally in a cross shape with a single point as the center, or a Radial scan that scans in multiple directions at predetermined angular intervals with a single point as the center, or even in the case of a 3D scan, when performing a follow-up examination for an examination in which fixation was stable and a tomographic image of the fovea was acquired in the past, it is possible to avoid the failure of the image acquisition in which the area of ​​interest is not captured.

[0067] From this point onward, the scanning flow is the same as that of a normal OCT device, so the explanation will be simplified. Once the imaging is complete, the system automatically transitions to a confirmation screen in step S107 to check the quality of the acquired images. The examiner determines whether the desired images were acquired and whether all imaging in the desired scan mode has been completed. If imaging fails, or if there is still imaging remaining in the desired scan mode, the system returns to step S102. Once it is confirmed that all imaging in the desired scan mode has been completed correctly, the system transitions to a report screen in step S109 to check the acquired images, analysis results, etc. On the report screen, the examiner will refer to the acquired images, analysis results, etc., and make a diagnosis.

[0068] As explained above, in the device of the first embodiment, even an examiner with low proficiency can easily and instantly confirm that the appropriate scan position has been set, i.e., that the designated areas of interest during diagnosis, such as the macula and papilla, have been correctly captured when setting the image acquisition position. At the same time, the time required for this confirmation can be shortened, thereby reducing the burden on the patient. Of course, it goes without saying that a switch could be provided to turn off this function when an examiner with sufficient proficiency uses the device.

[0069] <Example of transformation 1> Example 1 showed an example of an ophthalmic imaging device capable of reliably acquiring tomographic images containing the fovea, a designated area of ​​interest. However, this modified example shows an embodiment that is effective when to reliably confirm the area of ​​interest without moving the measurement range, as a tomographic image containing the area of ​​interest is not necessarily required, and in SLO preview.

[0070] In this modified ophthalmic imaging device, in addition to moving the entire scan range, it is possible to move the scan position indicated by the horizontal solid arrow 610 and the vertical dotted arrow 620 within the rectangles indicating the scan ranges 601 and 602, as shown in Figures 13(a), (b), (c), and (d). For example, Figure 13(b) shows the case where only the horizontal scan position is changed compared to Figure 13(a), Figure 13(c) shows the case where only the vertical scan position is changed compared to Figure 13(a), and Figure 13(d) shows the case where both the horizontal and vertical scan positions are changed compared to Figure 13(a). A GUI that enables such operations could, for example, allow dragging the solid arrow 610 and the dotted arrow 620, which are the first indicators that show the tomographic image acquisition position within the rectangle representing the scan range of 601 and 602, either directly or near the arrows themselves, to move only the solid arrow 610 and the dotted arrow 620. Dragging other parts of the rectangle representing the scan range of 601 and 602 would move the entire scan range. With such a GUI, during the preview stage before actual measurement, it becomes possible to align the position of the first indicator with the area of ​​interest without moving the scan range, and to reliably confirm only the tomographic image of the area of ​​interest.

[0071] <Transformation Example 2> In Example 1, when the analysis unit confirms the presence of the fovea in the tomographic image of the scan line corresponding to the position of the first indicator, the solid arrow 610 and / or the dotted line 620, the control unit 103 displays a second indicator indicating the presence of the fovea in the tomographic image on the periphery and / or outside of the tomographic image acquired at the position of the first indicator 610 and / or 620. However, the form in which the second indicator is displayed is not limited to this. At this time, the first indicators, arrows 610 and 620, may also be used as the second indicator by changing their display form, for example, by changing the display color or making them thicker, or both may be performed simultaneously in parallel. Since the examiner is paying close attention to the arrows 610, etc., which are the means of operation, when performing the operation, it becomes easier to distinguish and is even more effective. Furthermore, other forms of notification, such as a chime, may also be used in combination.

[0072] <Example 2> In Example 1, the configuration, operation, and effects of the optical coherence tomography apparatus according to the present invention were explained using the fovea in the macula as the object to be detected in the tomographic image and the detection timing as the preview state before measurement. However, the objects to which the effects of the present invention are applied are not limited to this. In Example 2, the object to be detected in the tomographic image is a candidate lesion, and an example is shown in which the present invention is applied to a confirmation screen that displays a tomographic image at which the timing for detecting the candidate lesion, which is the object to be detected, has been measured.

[0073] Figure 14 shows an example of a confirmation screen for checking the quality of images acquired in Macula3D scan mode, displayed in step S107 of the examination flow. Here, the confirmation screen described refers to a screen that displays the acquired OCT tomography and SLO images, and includes a button 750 that accepts instructions to save the acquired OCT tomography image, and a button 751 that accepts instructions to reacquire a new OCT tomography image. Since the confirmation screen is used in a process after acquiring tomography image data captured by an ophthalmic imaging device, the ophthalmic image processing device used in this embodiment may be not only an OCT device with tomography image data acquisition function and subsequent data processing function, but also an ophthalmic image processing device attached to an OCT device, or an ophthalmic image processing device that receives already acquired data from, for example, a data server and performs only data processing.

[0074] On the left side of the screen, from top to bottom, are the SLO image 700 taken at the time of acquisition and the projection image 710 generated from the acquired 3D OCT image. On the SLO image 700, the acquisition area is shown by rectangles 701 and 702, and three arrows 703, 704, and 705, which are the first indicators, are displayed at the center of the rectangle and the horizontal scan taken at the time of acquisition. On the projection image 710, arrows 713, 714, and 715, which are the first indicators, are displayed, indicating the horizontal scan positions corresponding to arrows 703, 704, and 705, respectively. On the right side of the screen, three horizontal tomographic images 720, 730, and 740, acquired from the acquired 3D OCT image at the scan positions of the first indicator arrows 713, 714, and 715, are displayed, respectively.

[0075] Here, the arrows 713, 714, and 715, which are the first indicators showing the tomographic image acquisition positions on the projection image 710, are each movable vertically (however, movement across arrows is not possible). For example, they can be manipulated by dragging the arrows themselves or their immediate vicinity with the mouse. This operation is also linked to the positions of arrows 703, 704, and 705 on the SLO image 700, moving them to the corresponding positions on the fundus. Furthermore, the three displayed tomographic images 720, 730, and 740 are also updated to the tomographic images at the positions indicated by arrows 713, 714, and 715. Through this operation, the examiner can observe the main scanning cross-sectional image at any position from the measured 3D tomographic image. The operation on the central arrows may also be performed by using the mouse wheel on the projection image 710 or 720. This would further improve usability.

[0076] In the GUI configured as described above, when the tomographic image 720 is updated, the analysis unit of the control unit 103 performs analysis of the updated tomographic image and attempts to extract candidate lesion areas within the tomographic image. This lesion detection method may use deep learning techniques, which have been the subject of recent research. However, in this embodiment, a method is adopted in which the boundaries of the retina of the eye under examination are detected, and candidate lesions are extracted from the distortion of the shape of the boundaries of predetermined layers and changes in film thickness. That is, the analysis unit first performs noise reduction and edge enhancement processing on the tomographic image to be processed. For noise reduction processing, for example, a median filter or a Gaussian filter is applied, and for edge enhancement processing, a Sobel filter or a Hessian filter is applied to enhance the linear structure in the tomographic image, i.e., the structure of the retinal layers. Next, boundary lines are detected from this edge-enhanced tomographic image. In this embodiment, the boundary between ILM and NFL, RPE, is first determined, and then, for example, the ISOS, and the boundary between NFL and GCL are detected. In addition, other boundaries may be detected, such as the boundary between the outer plexiform layer (OPL) and the outer granular layer (ONL), the boundary between the inner plexiform layer (IPL) and the inner granular layer (INL), the boundary between the INL and OPL, the boundary between the GCL and IPL, and the boundary between the choroid and the sclera. The boundary detection method involves detecting multiple boundary candidates in each A-scan where the edge intensity is strong, and then connecting the points as lines based on the continuity between the boundary candidates in adjacent A-scans. When connecting the points as lines, outliers are removed by evaluating the smoothness of the lines, and then the boundary is determined based on the distance and positional relationship with the upper and lower boundary lines. If no boundary is detected as a result of removing outliers in each A-scan, it may be determined by interpolation from the surrounding boundary lines. Alternatively, boundary candidate lines may be searched horizontally using edges from the surrounding boundary lines, and the boundary may be determined again based on the boundary candidate lines searched from the surrounding boundary lines.

[0077] Next, a process is performed to smooth the shape of the detected boundary lines. For example, the shape of the boundary lines may be smoothed using image features and shape features, such as with Snakes. Alternatively, the coordinate values ​​of the boundary line shape may be treated as time-series data from a signal, and the shape may be smoothed using a Savitzky-Golay filter, or smoothing processes such as a simple moving average, weighted moving average, or exponential moving average. Alternatively, instead of detecting boundary lines for all A scans, detection may be performed discretely (for example, at 5A scan intervals), and the boundary line positions of A scans where detection was not performed may be determined by interpolation from the detected boundary lines.

[0078] As described above, the thickness of a predetermined layer is calculated based on the detection results of the layer boundaries. The thickness of the predetermined layer may be, for example, the thickness of the NFL, or the thickness of a combined layer of NFL, GCL, and IPL. Alternatively, it may be the total thickness of all layers, including all layers from NFL (or ILM) to BM (or RPE). Since the calculated result is a value for one point per 1A scan, the thickness can be calculated for all A scans, and the film thickness distribution with respect to the main scanning direction of the tomographic image can be obtained.

[0079] Next, the analysis unit compares the positional relationship between the analyzed layer and the macula with the standard value at the corresponding position on the normative data. Sections where the calculated layer thickness is less than the 1st percentile of the confidence interval of the normative data are judged as abnormal sections, sections where it is less than the 5th percentile are boundary sections, and the remainder are judged as normal sections. Furthermore, sections where the locally coefficient of variation of the layer thickness distribution or the boundary of a predetermined layer exceeds a predetermined value may also be judged as sections with disturbances in the layer structure. In this embodiment, sections indicated by A on the tomographic image 720 shown in Figure 15, where the thickness distribution or the locally coefficient of variation of the boundary of a predetermined layer exceeds a predetermined value, and sections indicated by B, where the thickness distribution or the locally coefficient of variation of the boundary of a predetermined layer exceeds a predetermined value, are identified as candidate lesions.

[0080] As described above, if the analysis unit determines that there is no section identified as a lesion candidate in the tomographic image displayed in the display area 720 selected and displayed by arrow 713, the control unit 103 displays the display frame in which the tomographic image 720 is displayed in the normal display frame color (first color), such as black, as a normal indicator. However, if it determines that there is a section identified as a lesion candidate, it displays the display frame of the display area 720 in red (a different color from the first color) as a second indicator, as shown in Figure 15 (in this figure, it is displayed in gray for identification purposes). The above operations are performed each time the arrow 713 is moved and the tomographic image displayed in the display area 720 is updated. Furthermore, this display switching may be performed not only on the tomographic image displayed in the display area 720 when the tomographic image acquisition position is selected by arrow 713, but also on the tomographic images 730 and 740 acquired when the tomographic image acquisition position is selected by arrows 714 and 715.

[0081] The playback button 716 located below the projection image 710 is used to continuously move the position of the arrow 713 from the upper end position 711 to the lower end position 712, and to continuously update and display the tomographic image at the position corresponding to the arrow 713. This button is used to quickly review the entire obtained 3D volume OCT image. When the Play button is pressed, the display changes to a Stop button, and when the Stop button is pressed, playback can be stopped. When the horizontal arrow 713, i.e., the first indicator indicating the acquisition position (scan position) of the tomographic image 720, is continuously moved downwards, it may automatically stop after reaching the bottom, or it may loop playback by continuously displaying from the top. In addition, after displaying the projection image and tomographic image on the confirmation screen, playback may be set to start automatically, or the display time of tomographic images containing lesion candidates may be set to be longer during automatic playback. Furthermore, when automatic playback is used in this way, it is desirable to detect and determine the presence of lesion candidates for all tomographic images prior to display.

[0082] Furthermore, when the examiner clicks the "View all 760" button in the upper right corner of the screen, as shown in Figures 14 and 15, the system can switch from displaying three tomographic images at the positions of the first indicator arrows 713, 714, and 715 to displaying a list of all acquired tomographic images (2730-2734, 2740-2744) on the right side of the screen, as shown in Figure 16. In this case, the display frame of the tomographic image containing the lesion candidate is still indicated by the second indicator, which is red, and the tomographic images specified by arrows 713, 714, and 715 may be displayed larger on the projection image compared to the other tomographic images (for example, about 10% larger). In addition, as shown in Figure 16, it may be possible to display a list of OCT tomographic images acquired at a predetermined range of tomographic image acquisition positions, including the OCT tomographic image containing the lesion candidate displayed by the second indicator and its adjacent position. Alternatively, the system may be configured to automatically select and display the tomographic image showing the second indicator, or, after switching, the system may be configured to automatically select and display the OCT tomographic image showing the second indicator by default. Furthermore, if all OCT tomographic images cannot be displayed on the screen, a scroll bar may be displayed, and the user may select which tomographic images to display by operating the scroll bar.

[0083] Then, when the examiner clicks the Return button 761 in the upper right corner of the screen in Figure 16, they return to the original screen.

[0084] <Transformation Example 3> In the above-described Example 2, instead of the ★ mark used in Example 1 as a second indicator of the presence of a lesion candidate, a display frame of a different color from the normal display frame was used. However, the modified example shown in Figure 17 is also effective as a second indicator. In this modified example, the second indicator changes the color of the display frame only for the projection sections A', A'' and B', B'' of parts A and B, which are the parts where the lesion candidate exists, relative to the horizontal long side corresponding to the direction of the spread of the layers of the tomography image displayed in the OCT tomography image 720. In other words, it is an example of displaying the part of the display area frame that shows the location of the lesion candidate and the other parts in different colors to make them distinguishable. Furthermore, for different lesion candidates extracted using different criteria, the parts of the display frame corresponding to the parts where the lesion candidate exists may be displayed in different display colors. Similarly, a predetermined area and a lesion candidate may be displayed in different colors. Furthermore, parts A and B, which are the parts where the lesion candidate exists, may be surrounded and displayed with the second indicator as shown in Figure 17.

[0085] As described above, the second indicator not only indicates the presence of a predetermined candidate lesion, but also provides the examiner with information indicating the location of the candidate lesion without any unnecessary processing of the OCT tomography image 510. Although the above explanation uses an example of indicating the location of a candidate lesion, it may also indicate the location of a predetermined area. Since the OCT tomography image 510 is the image itself that was acquired and is suitable for diagnosis, its diagnostic value is guaranteed, and because the retina of the eye under examination is usually displayed as a thin membrane that extends in the layer direction, even just indicating a horizontal section is a sufficient indicator to draw the examiner's attention.

[0086] <Other examples of transformation> Furthermore, as shown in Figure 17, the location of the OCT tomographic image containing the lesion candidate within the display area frame (display frame) for displaying the projection image 710 may be indicated by a second indicator, a thick red line 717, or the extent of the lesion candidate's presence may be directly indicated on the projection image 710 along the boundary line of the lesion candidate using second display indicators, existence range markers 718A and 718B.

[0087] The above example illustrates how to display a second indicator showing the location of a potential lesion on the confirmation screen. However, the method is not limited to this example; it is also possible to display the second indicator on the aforementioned imaging screen or on the report screen showing the results of the analysis of the captured tomographic images.

[0088] Furthermore, in this embodiment, SLO preview images and projection images were used as examples of frontal fundus images for explanation, but it is clear that similar effects can be obtained by using infrared observation images from a two-dimensional sensor or by using EnFace images, etc.

[0089] <Other examples> Although the above-described embodiment was explained using SD-OCT, the present invention can be similarly applied to SS-OCT, or it may be applied to the screen for optical coherence tomography angiography (OCTA). In that case, the same area is repeatedly scanned, and components that change within a minute time (differences, changes in signal intensity, etc.) between the multiple tomographic images acquired, so-called motion contrast, are extracted. Motion contrast is a small signal for static structures, but a large signal for dynamic structures such as blood flow within blood vessels. Optical coherence tomography angiography is a new, non-invasive examination technique that replaces fluorescein angiography, allowing for three-dimensional observation of retinal and choroidal blood vessels by extracting and imaging this motion contrast.

[0090] The present invention has been described above using an ophthalmic device to which the present invention is applied as an example. However, the present invention can also be realized by supplying an ophthalmic image processing program that realizes one or more of the functions of the above embodiments to a system or device via a network or storage medium, and the computer of that system or device reads and executes the program. The computer has one or more processors or circuits and may include a plurality of separate computers or a network of a plurality of separate processors or circuits for the computer to read and execute executable instructions. The processor or circuit may include a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), or a field-programmable gateway (FPGA). The processor or circuit may also include a digital signal processor (DSP), a dataflow processor (DFP), or a neural processing unit (NPU). Furthermore, it can also be realized by a circuit that realizes one or more functions (for example, an ASIC). [Explanation of symbols]

[0091] 100 Head section 102 Base section 103 Control Unit 104 Storage section 105 Input section 106 Display section 510, 511, 512, 520 OCT preview tomographic images 521, 522 display area 540, 541 Second indicator 601, 602 Rectangle indicating scan range 603 Internal fixation light position 610, 611, 612, 620 First indicator Fault images 720, 730, 740

Claims

1. an image acquiring means for acquiring an OCT tomographic image and a front image of the fundus of the subject's eye; a display control means for displaying the acquired OCT tomographic image, the fundus front image, and a first index on the fundus front image, the first index indicating a position of the OCT tomographic image; An ophthalmologic image processing device comprising: The display control means An ophthalmologic image processing device characterized by controlling the display of a second indicator in at least one of the peripheral portion of the OCT tomographic image, on the image of the frontal fundus image, and the peripheral portion of the frontal fundus image when a specified area or suspected lesion is present in the OCT tomographic image.

2. 2 . The ophthalmologic image processing apparatus according to claim 1 , wherein the display control means displays the second index in a frame of a display area that displays the OCT tomographic image or the frontal fundus image.

3. 3. The ophthalmologic image processing apparatus according to claim 2, wherein the display control means displays the second indicator so as to indicate a position in the frontal fundus image where the predetermined region or a lesion candidate exists.

4. 2 . The ophthalmologic image processing apparatus according to claim 1 , wherein the display control means displays the second indicator along a boundary line of a lesion candidate on the frontal fundus image.

5. The ophthalmologic image processing device according to claim 2 or 3, characterized in that the display control means displays, as the second indicator, a portion of the frame of the display area displaying the OCT tomographic image that indicates the location of the specified area or lesion candidate and other portions in a distinguishable manner.

6. The ophthalmologic image processing apparatus according to claim 5 , wherein the distinguishable indication is displayed in different colors.

7. The ophthalmologic image processing device according to any one of claims 1 to 6, characterized in that the display control means controls the display of the second indicator in different colors for a specified area and a lesion candidate.

8. 8. The ophthalmologic image processing apparatus according to claim 1, wherein the display control means controls the second index so as to be switchable between display and non-display.

9. An ophthalmologic image processing device as described in any one of claims 1 to 8, characterized in that the image acquisition means sequentially acquires the frontal fundus image and the OCT tomographic image, and the display control means sequentially displays the acquired frontal fundus image and the OCT tomographic image.

10. An ophthalmologic image processing device as described in claim 9, characterized in that it has a fundus tracking means for maintaining the relative position between the first index and a newly acquired fundus image using the amount of movement of the fundus image based on the sequentially acquired frontal fundus images.

11. The display control means 11. The ophthalmologic image processing apparatus according to claim 1, further comprising a display unit capable of displaying the acquired OCT tomographic images together with the second index in a list.

12. The ophthalmologic image processing apparatus according to claim 11 , wherein the plurality of OCT tomographic images include OCT tomographic images acquired at adjacent positions on a fundus.

13. The display control means An ophthalmologic image processing device as described in any one of claims 1 to 12, characterized in that the acquired OCT tomographic image, the frontal fundus image, and the second indicator are displayed, and a button that can accept an instruction to save the acquired OCT tomographic image and an instruction to re-acquire a new OCT tomographic image is displayed.

14. An ophthalmic image processing device as described in any one of claims 1 to 13, characterized in that the specified area is at least one of the fovea, the macula, and the optic disc.

15. An ophthalmic image processing device as described in any one of claims 1 to 14, characterized in that the lesion candidate is obtained by analyzing the retinal boundary in the OCT tomographic image.

16. an image acquiring step of acquiring an OCT tomographic image and a front image of the fundus of the subject's eye; a display control step of displaying the acquired OCT tomographic image, the fundus front image, and a first index on the fundus front image, the first index indicating a position of the OCT tomographic image; An ophthalmological image processing program comprising: The display control step includes: An ophthalmologic image processing program characterized by having a step of displaying a second indicator in at least one of the peripheral portion of the OCT tomographic image, on the image of the frontal fundus image, and the peripheral portion of the frontal fundus image when a specified area or suspected lesion is present in the OCT tomographic image.

Images