Ophthalmic device and control method thereof

Abstract

To provide a new technique for performing plural times of inspection or measurement at an optimum working distance with simple structure and control.SOLUTION: An ophthalmologic apparatus comprises: an objective lens; a refractive power measurement optical system; an OCT optical system which has an optical scanner; an image formation unit which forms an image of an eye to be examined; a movement mechanism which relatively moves the objective lens, the refractive power measurement optical system and the OCT optical system in the optical axis direction of the objective lens; an operation unit; a control unit which controls the movement mechanism; and a fixation projection system which projects a fixation target to the eye to be examined. The control unit controls the fixation projection system so as to project the first fixation target to the eye to be examined when performing refractive power measurement, and project the second fixation target having the narrower visual angle than that of the first fixation target to the eye to be examined so as to be superimposed on the first fixation target when performing OCT measurement at a position of a cornea apex and a position of a central fovea performed for calculating optic axial length.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an ophthalmic apparatus and a control method thereof. [Background technology]

[0002] There is known an ophthalmic apparatus capable of performing a plurality of tests or measurements on a subject's eye. The tests or measurements on the subject's eye include subjective tests and objective measurements. The subjective tests obtain results based on responses from the subject. The objective measurements obtain information on the subject's eye mainly by using physical techniques without referring to responses from the subject.

[0003] For example, Patent Document 1 discloses an ophthalmic device capable of subjective examination and objective measurement. As objective measurements, this ophthalmic device can perform refractive power measurement of the subject's eye, keratometry, and imaging or measurement using optical coherence tomography.

[0004] In a plurality of tests or measurements using such an ophthalmic device, the optimal working distance is different from each other. Therefore, when the working distance of the ophthalmic device is set to be optimal for one test or measurement, the range of another test or measurement is narrowed or the measurement accuracy is reduced. For example, when the working distance of the ophthalmic device is set to be optimal for refractive power measurement, the scan range in optical coherence tomography (hereinafter, OCT) measurement is narrowed. For example, when the working distance of the ophthalmic device is set to be optimal for OCT measurement, it is easily affected by instrument myopia. This requires a larger diameter of the objective lens. However, when the diameter of the objective lens is increased, it becomes difficult to project the measurement pattern used in keratometry, and the corneal shape cannot be measured with high accuracy.

[0005] There has been proposed an ophthalmic device capable of changing the working distance of the ophthalmic device according to the type of examination or measurement. For example, Patent Document 2 and Patent Document 3 disclose an ophthalmic device including a measurement unit in which a refractive power / corneal shape measurement unit and an intraocular pressure measurement unit are stacked in the vertical direction. In this ophthalmic device, the measurement unit is moved in the vertical direction and the intraocular pressure measurement unit is moved in the working distance direction relative to the refractive power / corneal shape measurement unit, thereby making it possible to set the optimal working distance for each of the refractive power / corneal shape measurement and the intraocular pressure measurement. For example, Patent Document 4 discloses an ophthalmic device in which an eye examination unit including a refractive power measurement unit and an intraocular pressure measurement unit is provided so as to be rotatable around a rotation axis relative to a base. In this ophthalmic device, the eye examination unit is rotated to perform measurements at optimal working distances for each of the refractive power measurement and the intraocular pressure measurement. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-136215 A [Patent Document 2] Patent No. 4349934 specification [Patent Document 3] Patent No. 4879632 specification [Patent Document 4] Patent No. 6016445 specification Summary of the Invention [Problem to be solved by the invention]

[0007] However, in conventional ophthalmic devices, multiple measurement units are stacked and a rotation mechanism for the optometry unit is required, which leads to an increase in the size of the device and a complicated control of the device.

[0008] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a new technique for performing multiple inspections or measurements at optimal working distances for each with a simple configuration and control. [Means for solving the problem]

[0009] A first aspect of some embodiments is an ophthalmic device including: an objective lens; a refractive power measurement optical system that projects light onto a test eye through the objective lens and detects return light from the test eye; an OCT optical system having an optical scanner, dividing light from a light source into measurement light and reference light, deflecting the measurement light by the optical scanner, projecting the measurement light deflected by the optical scanner onto the test eye through the objective lens, and detecting interference light between the return light from the test eye and the reference light; an image forming unit that forms an image of the test eye based on the detection result of the interference light; a moving mechanism that moves the objective lens, the refractive power measurement optical system, and the OCT optical system relatively in the optical axis direction of the objective lens with respect to the test eye; an operation unit; and a control unit that controls the moving mechanism so that a predetermined working distance is achieved with respect to the test eye when performing refractive power measurement using the refractive power measurement optical system, displays the image formed by the image forming unit on a display means when performing OCT measurement using the OCT optical system, and controls the moving mechanism based on the operation content on the operation unit.

[0010] In a second aspect of some embodiments, in the first aspect, the image forming unit forms a tomographic image of an area including an area corresponding to a cornea of ​​the subject's eye.

[0011] A third aspect of some embodiments is an ophthalmic device including: an objective lens; a refractive power measuring optical system that projects light onto a test eye through the objective lens and detects return light from the test eye; an OCT optical system having an optical scanner, dividing light from a light source into measurement light and reference light, deflecting the measurement light by the optical scanner, projecting the measurement light deflected by the optical scanner onto the test eye through the objective lens, and detecting interference light between the return light from the test eye and the reference light; an identification unit that identifies a position of a specific site of the test eye based on a detection result of the interference light; a moving mechanism that moves the objective lens, the refractive power measuring optical system, and the OCT optical system relatively in the optical axis direction of the objective lens with respect to the test eye; and a control unit that controls the moving mechanism so that a specific working distance is achieved with respect to the test eye when performing refractive power measurement using the refractive power measuring optical system, and controls the moving mechanism based on the position of the specific site identified by the identification unit when performing OCT measurement using the OCT optical system.

[0012] In a fourth aspect of some embodiments, in the third aspect, the predetermined site includes an area corresponding to the cornea.

[0013] A fifth aspect of some embodiments, in any of the first to fourth aspects, includes an alignment optical system that irradiates alignment light onto the test eye from a direction different from the optical axis direction of the objective lens and detects the returned light, and the control unit controls the moving mechanism based on the detection results obtained by the alignment optical system when performing the refractive power measurement.

[0014] A sixth aspect of some embodiments, in any of the first to fifth aspects, includes an anterior segment observation system including a relay lens that relays light from an anterior segment of the test eye and an image sensor that receives light that has passed through the relay lens, and the control unit moves the relay lens to a first lens position on the optical axis of the anterior segment observation system when performing the refractive power measurement, and moves the relay lens to a second lens position on the optical axis of the anterior segment observation system when performing the OCT measurement.

[0015] A seventh aspect of some embodiments, in any of the first to sixth aspects, includes a fixation projection system that projects a fixation target onto the test eye, and the control unit controls the fixation projection system to project a first fixation target onto the test eye when performing the refractive power measurement, and to project a second fixation target having a narrower visual angle than the first fixation target onto the test eye when performing the OCT measurement.

[0016] In an eighth aspect of some embodiments, in the seventh aspect, the second fixation target is a dot target or a cross target.

[0017] A ninth aspect of some embodiments is a control method for an ophthalmic device including an objective lens, a refractive power measuring optical system that projects light onto a test eye through the objective lens and detects return light from the test eye, an OCT optical system having an optical scanner, splitting light from a light source into measurement light and reference light, deflecting the measurement light by the optical scanner, projecting the measurement light deflected by the optical scanner onto the test eye through the objective lens, and detecting interference light between the return light from the test eye and the reference light, a moving mechanism that moves the objective lens, the refractive power measuring optical system, and the OCT optical system relatively to the test eye in the optical axis direction of the objective lens, an operation unit, and a control unit that controls at least the moving mechanism. The control method for an ophthalmic apparatus includes a first control step of controlling the moving mechanism so as to achieve a predetermined working distance with respect to the test eye, a first measurement step of controlling the refractive power measurement optical system to perform a refractive power measurement after the working distance is changed in the first control step, an image formation step of forming an image of the test eye based on a detection result of the interference light, a second control step of displaying the image formed in the image formation step on a display means and controlling the moving mechanism based on the operation content on the operation unit, and a second measurement step of controlling the OCT optical system to perform an OCT measurement after the working distance is changed in the second control step.

[0018] A tenth aspect of some embodiments is a control method for an ophthalmic device including an objective lens, a refractive power measuring optical system that projects light onto a test eye through the objective lens and detects return light from the test eye, an OCT optical system having an optical scanner, splitting light from a light source into measurement light and reference light, deflecting the measurement light by the optical scanner, projecting the measurement light deflected by the optical scanner onto the test eye through the objective lens, and detecting interference light between the return light from the test eye and the reference light, a moving mechanism that moves the objective lens, the refractive power measuring optical system, and the OCT optical system relatively in the optical axis direction of the objective lens with respect to the test eye, and a control unit that controls at least the moving mechanism. The control method for an ophthalmic apparatus includes a first control step of controlling the moving mechanism so as to achieve a predetermined working distance with respect to the test eye, a first measurement step of controlling the refractive power measurement optical system to perform a refractive power measurement after the working distance is changed in the first control step, an identification step of identifying a position of a predetermined portion of the test eye based on a detection result of the interference light, a second control step of controlling the moving mechanism based on the position of the predetermined portion identified in the identification step, and a second measurement step of controlling the OCT optical system to perform an OCT measurement after the working distance is changed in the second control step.

[0019] In an eleventh aspect of some embodiments, in the ninth or tenth aspect, the ophthalmic apparatus includes an alignment optical system that irradiates the test eye with alignment light from a direction different from an optical axis direction of the objective lens and detects the return light. The first control step includes a step of controlling the moving mechanism based on a detection result obtained by the alignment optical system.

[0020] In a twelfth aspect of some embodiments, in any one of the ninth to eleventh aspects, the ophthalmic apparatus includes an anterior-segment observation system including a relay lens that relays light from an anterior segment of the subject's eye, and an image sensor that receives light that has passed through the relay lens. A control method for the ophthalmic apparatus includes a first lens moving step of moving the relay lens to a first lens position on an optical axis of the anterior-segment observation system when performing the refractive power measurement, and a second lens moving step of moving the relay lens to a second lens position on the optical axis of the anterior-segment observation system when performing the OCT measurement.

[0021] In a thirteenth aspect of some embodiments, in any one of the ninth to twelfth aspects, the ophthalmologic apparatus includes a fixation projection system that projects a fixation target onto the subject's eye. The first measurement step includes a first projection step of controlling the fixation projection system to project a first fixation target onto the subject's eye. The second measurement step includes a second projection step of controlling the fixation projection system to project a second fixation target having a narrower visual angle than the first fixation target onto the subject's eye. Effect of the Invention

[0022] According to the present invention, it is possible to provide a new technique for performing a plurality of inspections or measurements at optimal working distances for each with a simple configuration and control. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. [Diagram 2] 1 is a schematic diagram illustrating an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. [Diagram 3] 1 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to an embodiment. [Figure 4] 1 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to an embodiment. [Diagram 5] 2 is a schematic diagram illustrating an example of the configuration of a processing system of an ophthalmic apparatus according to an embodiment. FIG. [Figure 6A]1 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to an embodiment. [Figure 6B] 1 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to an embodiment. [Figure 7] 5 is a schematic diagram showing a flow of an example of an operation of the ophthalmologic apparatus according to the embodiment. FIG. [Figure 8] 10 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to a modified example of the embodiment. FIG. [Figure 9] 10 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to a modified example of the embodiment. FIG. [Figure 10] 10 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to a modified example of the embodiment. FIG. [Figure 11] 10 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to a modified example of the embodiment. FIG. [Figure 12] 5 is a schematic diagram showing a flow of an example of an operation of the ophthalmologic apparatus according to the embodiment. FIG. [Figure 13] 10 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to a modified example of the embodiment. FIG. [Figure 14] 10 is a schematic diagram for explaining an optical system of an ophthalmic apparatus according to a modified example of the embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] An ophthalmic device and a control method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the contents of documents cited in this specification and any publicly known techniques can be incorporated in the following embodiments.

[0025] The ophthalmic apparatus according to the embodiment is capable of performing a plurality of examinations or measurements while sharing an objective lens. In the ophthalmic apparatus capable of performing a plurality of examinations or measurements, the objective lens is shared among a plurality of optical systems corresponding to the types of examinations or measurements, thereby making it possible to reduce the size and cost of the apparatus.

[0026] The ophthalmic apparatus according to the embodiment can perform refractive power measurement (REF measurement) and scan measurement. In the scan measurement, measurement results are obtained by deflecting light for measurement, projecting the deflected light onto the subject's eye, and detecting return light from the subject's eye. The scan measurement includes measurement or photography using optical coherence tomography. In the following, a case will be described in which the ophthalmic apparatus according to the embodiment performs OCT on the anterior segment and fundus as the scan measurement. In some embodiments, measurement or photography using a scanning laser ophthalmoscope (SLO) optical system is performed as the scan measurement.

[0027] In the following embodiments, the case where a swept-source type OCT technique is used will be described in detail, but the configuration according to the embodiment can also be applied to ophthalmic apparatuses that use other types of OCT (e.g., spectral domain type, time domain type).

[0028] In some embodiments, the ophthalmic device further includes subjective testing optics for performing subjective testing, or an objective measurement system for performing other objective measurements.

[0029] Subjective tests are measurement techniques that obtain information from the subject's responses. Subjective tests include subjective refraction measurements such as distance tests, near tests, contrast tests, and glare tests, as well as visual field tests.

[0030] Objective measurement is a measurement technique that obtains information about the subject's eye mainly by using physical techniques without referring to responses from the subject. Objective measurement includes measurement for obtaining characteristics of the subject's eye and photography for obtaining an image of the subject's eye. Other objective measurements include intraocular pressure measurement, fundus photography, etc.

[0031] Hereinafter, the fundus conjugate position is a position that is approximately optically conjugate with the fundus of the subject eye after the alignment is complete, and refers to a position that is optically conjugate with the fundus of the subject eye or its vicinity. Similarly, the pupil conjugate position is a position that is approximately optically conjugate with the pupil of the subject eye after the alignment is complete, and refers to a position that is optically conjugate with the pupil of the subject eye or its vicinity.

[0032] Hereinafter, the working distance is defined as the distance from the subject's eye to the tip of the ophthalmic device. The tip of the ophthalmic device may include, for example, the object-side lens surface of the objective lens, or a part of the device body (housing) such as a keratoconduit. In some embodiments, the working distance is the distance on the optical axis of the objective lens.

[0033] <Optical system configuration> 1 and 2 show an example of the configuration of an optical system of an ophthalmic apparatus according to an embodiment. The ophthalmic apparatus 1000 according to the embodiment includes an optical system for observing an eye E, an optical system for inspecting the eye E, and a dichroic mirror for wavelength separation of the optical paths of these optical systems. An anterior eye observation system 5 is provided as an optical system for observing the eye E. An OCT optical system and a refraction measurement optical system (refractive power measurement optical system) are provided as optical systems for inspecting the eye E.

[0034] The ophthalmic apparatus 1000 includes a Z alignment system 1, an XY alignment system 2, a keratometry system 3, a fixation projection system 4, an anterior eye observation system 5, a reflex measurement projection system 6, a reflex measurement light receiving system 7, and an OCT optical system 8. In the following, for example, it is assumed that the anterior eye observation system 5 uses light of 940 nm to 1000 nm, the reflex measurement optical systems (reflex measurement projection system 6, reflex measurement light receiving system 7) use light of 830 nm to 880 nm, the fixation projection system 4 uses light of 400 nm to 700 nm, and the OCT optical system 8 uses light of 1000 nm to 1100 nm.

[0035] (Anterior segment observation system 5) The anterior eye observation system 5 captures a moving image of the anterior eye of the subject's eye E. In the optical system passing through the anterior eye observation system 5, the imaging surface of the imaging element 59 is disposed at a pupil conjugate position. The anterior eye illumination light source 50 irradiates the anterior eye of the subject's eye E with illumination light (e.g., infrared light). The light reflected by the anterior eye of the subject's eye E passes through the objective lens 51, transmits the dichroic mirror 52, passes through a hole formed in the aperture (telecentric aperture) 53, transmits the half mirror 23, passes through the relay lenses 55 and 56, and transmits the dichroic mirror 76. The dichroic mirror 52 combines (separates) the optical path of the reflex measurement optical system and the optical path of the anterior eye observation system 5. The dichroic mirror 52 is disposed such that the optical path combining surface that combines these optical paths is inclined with respect to the optical axis of the objective lens 51. In the embodiment, the relay lens 56 is movable along the optical axis of the anterior eye observation system 5 (or the optical axis of the relay lens 56). The light transmitted through the dichroic mirror 76 is imaged on the imaging surface of an imaging element 59 (area sensor) by an imaging lens 58. The imaging element 59 performs imaging and signal output at a predetermined rate. The output (video signal) of the imaging element 59 is input to a processing unit 9 described later. The processing unit 9 displays an anterior eye image E' based on this video signal on a display screen 10a of a display unit 10 described later. The anterior eye image E' is, for example, an infrared moving image.

[0036] (Z alignment system 1) The Z alignment system 1 is used for alignment of the optical axis direction (front-back direction, Z direction, working distance direction) of the objective lens 51 (optical system such as the anterior eye observation system 5) before reflex measurement. Note that the alignment of the optical axis direction of the objective lens 51 before OCT measurement is performed based on the detection result of interference light obtained by the OCT optical system 8, as described later.

[0037] The Z alignment system 1 projects light (infrared light) for alignment in the optical axis direction of the objective lens 51 onto the subject's eye E. The light output from the Z alignment light source 11 is projected onto the cornea Cr of the subject's eye E at a predetermined position on the optical axis of the objective lens 51, reflected by the cornea Cr, and imaged onto the sensor surface of the line sensor 13 by the imaging lens 12. When the position of the corneal apex changes in the optical axis direction of the anterior segment observation system 5 (the optical axis direction of the objective lens 51), the projection position of the light on the sensor surface of the line sensor 13 changes. Before the reflex measurement, the processing unit 9 determines the position of the corneal apex of the subject's eye E based on the projection position of the light on the sensor surface of the line sensor 13, and performs Z alignment by controlling a mechanism that moves the optical system based on this.

[0038] (XY alignment system 2) The XY alignment system 2 irradiates the subject's eye E with light (infrared light) for alignment in directions (left-right direction (X direction) and up-down direction (Y direction)) perpendicular to the optical axis of the anterior-eye observation system 5. The XY alignment system 2 includes an XY alignment light source 21 and a collimator lens 22 provided on an optical path branched off from the optical path of the anterior-eye observation system 5 by a half mirror 23. The light output from the XY alignment light source 21 passes through the collimator lens 22, is reflected by the half mirror 23, and is projected onto the subject's eye E through the anterior-eye observation system 5. The light reflected by the cornea Cr of the subject's eye E is guided to the image sensor 59 through the anterior-eye observation system 5.

[0039] The image (bright spot image) Br based on this reflected light is included in the anterior eye image E'. The processing unit 9 displays the anterior eye image E' including the bright spot image Br and the alignment mark AL on the display screen of the display unit. When performing manual XY alignment, the user moves the optical system so as to guide the bright spot image Br into the alignment mark AL. When performing automatic alignment, the processing unit 9 controls a mechanism for moving the optical system so that the displacement of the bright spot image Br relative to the alignment mark AL is canceled.

[0040] (Kerato measurement system 3) The kerato measurement system 3 projects a ring-shaped light beam (infrared light) onto the cornea Cr of the subject's eye E to measure the shape of the cornea Cr. The kerato plate 31 is disposed between the objective lens 51 and the subject's eye E. The kerato plate 31 is provided on the rear side (objective lens 51 side) of the kerato plate 31 with a kerato ring light source 32. The kerato plate 31 is formed with a kerato pattern (transmitting portion) that transmits light from the kerato ring light source 32 along a circumference centered on the optical axis of the objective lens 51. The kerato pattern may be formed in an arc shape (part of the circumference) centered on the optical axis of the objective lens 51. By illuminating the kerato plate 31 with light from the kerato ring light source 32, a ring-shaped light beam (arc-shaped or circumferential measurement pattern) is projected onto the cornea Cr of the subject's eye E. The reflected light (keratinization image) from the cornea Cr of the subject's eye E is detected together with the anterior eye image E' by the imaging element 59. The processing unit 9 performs a known calculation based on this keratinization image to calculate corneal shape parameters that represent the shape of the cornea Cr.

[0041] (Reflective measurement projection system 6, Reflective measurement receiving system 7) The refraction measurement optical system includes a refraction measurement projection system 6 and a refraction measurement light receiving system 7 used for refractive power measurement. The refraction measurement projection system 6 projects a light beam (e.g., a ring-shaped light beam) (infrared light) for refractive power measurement onto the fundus Ef. The refraction measurement light receiving system 7 receives the return light of this light beam from the subject's eye E. The refraction measurement projection system 6 is provided on an optical path branched by an aperture prism 65 provided on the optical path of the refraction measurement light receiving system 7. The hole formed in the aperture prism 65 is positioned at the pupil conjugate position. In the optical system passing through the refraction measurement light receiving system 7, the imaging surface of the image sensor 59 is positioned at the fundus conjugate position.

[0042] In some embodiments, the reflex measurement light source 61 is a superluminescent diode (SLD) light source, which is a high-brightness light source. The reflex measurement light source 61 is movable in the optical axis direction. The reflex measurement light source 61 is disposed at a fundus conjugate position. The light output from the reflex measurement light source 61 passes through a relay lens 62 and enters a conical surface of a conical prism 63. The light that enters the conical surface is deflected and exits from the bottom surface of the conical prism 63. The light that exits from the bottom surface of the conical prism 63 passes through a light-transmitting portion formed in a ring shape in the ring aperture 64. The light (ring-shaped light beam) that passes through the light-transmitting portion of the ring aperture 64 is reflected by a reflecting surface formed around the hole of the hole prism 65, passes through the rotary prism 66, and is reflected by the dichroic mirror 67. The light reflected by the dichroic mirror 67 is reflected by the dichroic mirror 52, passes through the objective lens 51, and is projected onto the subject's eye E. The rotary prism 66 is used to average the light intensity distribution of the ring-shaped light beam on the blood vessels or diseased area of ​​the fundus Ef, or to reduce speckle noise caused by the light source.

[0043] The return light of the ring-shaped light beam projected on the fundus Ef passes through the objective lens 51 and is reflected by the dichroic mirror 52 and the dichroic mirror 67. The return light reflected by the dichroic mirror 67 passes through the rotary prism 66, passes through the hole of the aperture prism 65, passes through the relay lens 71, is reflected by the reflecting mirror 72, and passes through the relay lens 73 and the focusing lens 74. The focusing lens 74 is movable along the optical axis of the reflector measurement light receiving system 7. The light passing through the focusing lens 74 is reflected by the reflecting mirror 75, is reflected by the dichroic mirror 76, and is imaged on the imaging surface of the imaging element 59 by the imaging lens 58. The processing unit 9 calculates the refractive power value of the subject's eye E by performing a known calculation based on the output from the imaging element 59. For example, the refractive power value includes a spherical power, a cylindrical power and an astigmatism axis angle, or an equivalent spherical power.

[0044] (Fixation projection system 4) The OCT optical system 8 described below is provided on an optical path separated by wavelength from the optical path of the reflex measurement optical system by the dichroic mirror 67. The fixation projection system 4 is provided on an optical path branched off from the optical path of the OCT optical system 8 by the dichroic mirror 83.

[0045] The fixation projection system 4 presents a fixation target to the subject's eye E. A fixation unit 40 is disposed in the optical path of the fixation projection system 4. The fixation unit 40 is movable along the optical path of the fixation projection system 4 under the control of a processing unit 9, which will be described later. The fixation unit 40 includes a liquid crystal panel 41. A relay lens 42 is disposed between the dichroic mirror 83 and the fixation unit 40.

[0046] The liquid crystal panel 41, controlled by the processing unit 9, displays a pattern representing a fixation target. By changing the display position of the pattern on the screen of the liquid crystal panel 41, the fixation position of the subject's eye E can be changed. The fixation positions of the subject's eye E include a position for acquiring an image centered on the macular portion of the fundus Ef, a position for acquiring an image centered on the optic disc, and a position for acquiring an image centered on the center of the fundus between the macular portion and the optic disc. The display position of the pattern representing the fixation target can be changed arbitrarily.

[0047] Light from the liquid crystal panel 41 passes through the relay lens 42, transmits through the dichroic mirror 83, passes through the relay lens 82, is reflected by the reflecting mirror 81, transmits through the dichroic mirror 67, and is reflected by the dichroic mirror 52. The light reflected by the dichroic mirror 52 passes through the objective lens 51 and is projected onto the fundus Ef. In some embodiments, each of the liquid crystal panel 41 and the relay lens 42 is independently movable in the optical axis direction.

[0048] (OCT optical system 8) The OCT optical system 8 is an optical system for performing OCT measurement. Based on the result of a refraction measurement performed before the OCT measurement, the position of the focusing lens 87 is adjusted so that the end face of the optical fiber f1 is conjugate with the imaging site (fundus Ef or anterior segment) and the optical system.

[0049] The OCT optical system 8 is provided on an optical path that is wavelength-separated from the optical path of the reflex measurement optical system by a dichroic mirror 67. The optical path of the fixation projection system 4 is coupled to the optical path of the OCT optical system 8 by a dichroic mirror 83. This allows the optical axes of the OCT optical system 8 and the fixation projection system 4 to be coaxially coupled.

[0050] The OCT optical system 8 includes an OCT unit 100. As shown in Fig. 2, in the OCT unit 100, an OCT light source 101 includes a wavelength sweep type (wavelength scanning type) light source capable of sweeping (scanning) the wavelength of emitted light, similar to a general swept-source type OCT device. The wavelength sweep type light source includes a laser light source including a resonator. The OCT light source 101 changes the output wavelength over time in the near-infrared wavelength band that is not visible to the human eye.

[0051] 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 a function of splitting light from a wavelength-variable light source (wavelength-swept light source) into measurement light and reference light, a function of superimposing return light of the measurement light from the subject's eye E and the reference light that has passed through a reference light path to generate interference light, and a function of 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 a processing unit 9.

[0052] The OCT light source 101 includes, for example, a near-infrared tunable laser that changes the wavelength of the emitted light (wavelength range of 1000 nm to 1100 nm) at high speed. The light L0 output from the OCT light source 101 is guided to a polarization controller 103 by an optical fiber 102, where its polarization state is adjusted. The light L0 whose polarization state has been adjusted is guided to a fiber coupler 105 by an optical fiber 104, where it is split into a measurement light LS and a reference light LR.

[0053] The reference light LR is guided by an optical fiber 110 to a collimator 111 where it is converted into a parallel beam, and is 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.

[0054] 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 light beam to a focused light 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 a polarization controller 118 where its polarization state is adjusted, is guided by the optical fiber 119 to an attenuator 120 where the amount of light is adjusted, and is guided by the optical fiber 121 to a fiber coupler 122.

[0055] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided through the optical fiber f1 and converted into a parallel beam by the collimator lens unit 89, passes through the optical scanner 88, the focusing lens 87, the relay lens 85, and the reflecting mirror 84, and is reflected by the dichroic mirror 83.

[0056] The optical scanner 88 deflects the measurement light LS one-dimensionally or two-dimensionally. The optical scanner 88 includes, for example, a first galvanometer mirror and a second galvanometer mirror. The first galvanometer mirror deflects the measurement light LS so as to scan the imaging site (fundus Ef or anterior segment) in a horizontal direction perpendicular to the optical axis of the OCT optical system 8. The second galvanometer mirror deflects the measurement light LS deflected by the first galvanometer mirror so as to scan the imaging site in a vertical direction perpendicular to the optical axis of the OCT optical system 8. Examples of the scanning mode of the measurement light LS by such an optical scanner 88 include horizontal scan, vertical scan, cross scan, radial scan, circular scan, concentric circle scan, and spiral scan.

[0057] The measurement light LS reflected by the dichroic mirror 83 passes through the relay lens 82, is reflected by the reflecting mirror 81, passes through the dichroic mirror 67, is reflected by the dichroic mirror 52, is refracted by the objective lens 51, 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 in the opposite direction along the same path as the outward path and is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

[0058] 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.

[0059] The detector 125 is, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that detect a pair of interference lights LC, respectively, and outputs a difference between a pair of detection results obtained by these photodetectors. The detector 125 sends this output (detection signal) to a DAQ (Data Acquisition System) 130.

[0060] The DAQ130 is supplied with a clock KC from the OCT light source 101. The clock KC is generated in the OCT light source 101 in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength-variable light source. For example, the OCT light source 101 optically delays one of two branched lights obtained by branching the light L0 of each output wavelength, and generates the clock KC based on the result of detecting the combined light. The DAQ130 samples the detection signal input from the detector 125 based on the clock KC. The DAQ130 sends the sampling result of the detection signal from the detector 125 to the arithmetic processing unit 220 of the processing unit 9. The arithmetic processing unit 220 forms a reflection intensity profile in each A line by performing a Fourier transform or the like on the spectral distribution based on the sampling data for each series of wavelength scans (for each A line). Furthermore, the arithmetic processing unit 220 forms image data by imaging the reflection intensity profile of each A line.

[0061] In this example, a corner cube 114 is provided to change the length of the optical path (reference optical path, reference arm) of the reference light LR, but it is also possible to change the difference between the measurement optical path length and the reference optical path length using optical components other than these.

[0062] The processing unit 9 calculates a refractive power value from a measurement result obtained using the refraction measurement optical system, and based on the calculated refractive power value, moves each of the refraction measurement light source 61 and the focusing lens 74 in the optical axis direction to a position where the fundus Ef, the refraction measurement light source 61, and the image sensor 59 are conjugate with each other. In some embodiments, the processing unit 9 moves the focusing lens 87 of the OCT optical system 8 in the optical axis direction in conjunction with the movement of the focusing lens 74. In some embodiments, the processing unit 9 moves the liquid crystal panel 41 (fixation unit 40) in the optical axis direction in conjunction with the movement of the refraction measurement light source 61 and the focusing lens 74.

[0063] The ophthalmic apparatus 1000 according to the embodiment is capable of changing the working distance between the refraction measurement (refractive power measurement) using the refraction measurement optical system and the OCT measurement using the OCT optical system 8, while sharing an objective lens at least in the refraction measurement optical system and the OCT optical system 8. This makes it possible to obtain highly accurate refraction measurement results and highly accurate OCT measurement results with a simple configuration, while ensuring the scan range of the OCT optical system 8.

[0064] [Working distance when performing reflectance measurement] In the ophthalmic apparatus 1000 according to the embodiment, the working distance (first working distance) is set so as not to be affected by instrumental myopia when performing reflex measurement. When the ophthalmic apparatus 1000 includes a keratometry system 3, this working distance is preferably a working distance that allows acquisition of keratometry results useful for corneal topography analysis.

[0065] Fig. 3 is an explanatory diagram of the working distance when performing a reflex measurement according to the embodiment. Fig. 3 is an enlarged view of a part of the optical system in Fig. 1. In Fig. 3, the same parts as in Fig. 1 are given the same reference numerals, and the description will be omitted as appropriate.

[0066] The keratometry system 3 is a telecentric optical system that can obtain a keratometry ring image whose height does not change even if the working distance changes. When light is projected onto the cornea Cr by the keratometry system 3, the cornea acts as a convex mirror, and an image appears that is mainly reflected by the front surface of the cornea Cr.

[0067] The radius of curvature of the cornea Cr of the subject's eye E is R, the height of the keratinizing image relative to the optical axis of the objective lens 51 is h, and the projection angle of the ring-shaped light beam relative to the optical axis is α. In order to position a ring pattern (measurement pattern) at the incident position of the ring-shaped light beam from the keratinizing light source 32, the following equation is established when the angle that the line connecting the center of curvature of the cornea Cr and the incident position makes with the optical axis is β.

[0068] h = R × sin(β) (1) β=α / 2 (2)

[0069] The radius of the kerato pattern formed on the kerato plate 31 is H, the distance from the kerato plate 31 to the subject's eye E (corneal apex) is the working distance WDref, and the distance between the incident position of the ring-shaped light beam and the corneal apex Δd(=R-√(R 2 -h 2 )), the following equation holds:

[0070] H=(WDref+(R-√(R 2 -h 2 ))) × tan(α) + h (3)

[0071] As described above, in the ophthalmic apparatus 1000 according to the embodiment, when performing a reflex measurement, the working distance WDref is set to the working distance WDref shown in the following formula (4). Formula (4) can be obtained by substituting formulas (1) and (2) into formula (3).

[0072] WDref = ((Hh) / tan(2 × sin -1 (h / R))-(R-√(R 2 -h 2 ))) ···(4)

[0073] In some embodiments, known data such as a model eye is used for the radius of curvature R. The effective diameter D of the objective lens 51 can be determined from the radius H of the keratin ring pattern.

[0074] For example, to measure the corneal shape of an area of ​​φ3 on the cornea Cr that is useful for corneal topography, h=1.5 millimeters.

[0075] As described above, when performing refraction measurement, by setting the working distance WDref shown in formula (4), it is possible to lengthen the working distance and reduce the influence of instrument myopia while preventing an increase in the size of the keratoplasty plate 31. This makes it possible to provide an ophthalmic device that can obtain highly accurate refraction measurement results or keratoplasty measurement results with a simple configuration.

[0076] [Working distance when performing OCT measurements] When performing OCT measurement, the working distance can be set manually or automatically. In the case of automatic setting, in the ophthalmic apparatus 1000 according to the embodiment, the working distance (second working distance) is set so that at least a scan range useful for analysis using standard data can be scanned when performing OCT measurement. The standard data is statistically derived from a large number of normal eye measurement data and information on the subject of the measurement data, and is called normal eye data (normative data), etc. The working distance set when performing OCT measurement may be a working distance that can scan the scan range (or a range wider than the scan range) when the measurement data used to derive the above-mentioned standard data is acquired.

[0077] Fig. 4 is an explanatory diagram of the working distance when performing OCT measurement according to the embodiment. Fig. 4 is an enlarged view of a part of the optical system in Fig. 1. In Fig. 4, the same parts as in Fig. 1 are given the same reference numerals, and the description will be omitted as appropriate.

[0078] In order to obtain data of a desired scan range without exhaustively, the optical scanner 88 deflects the measurement light LS in each of the X direction and the Y direction. If the scan range of the fundus Ef is a range of RA×RA, the optical scanner 88 needs to deflect at least RA×√2 (=SA) in each direction.

[0079] Here, the optical scanner 88 is disposed so as to be approximately optically conjugate with the pupil of the subject's eye E. The working distance is WDoct, the distance from the anterior surface of the cornea to the pupil is La, the distance from the pupil to the fundus is Le, and the distance from the keratoplastinum 31 (the surface on the subject's eye E side) to the main surface of the objective lens 51 is Lk. Due to the similarity relationship between a triangle with the pupil as the apex and the radius of the objective lens 51 as the base, and a triangle with the pupil as the apex and the base of the scan range SA / 2 at the fundus Ef, the scan range SA satisfies the following formula.

[0080] SA=Le×D / (WDoct+La+Lk) ···(5)

[0081] From the above, in the ophthalmic apparatus 1000 according to the embodiment, when performing OCT measurement, the working distance WDoct is set to be as shown in the following formula (6).

[0082] WDoct=(Le×D) / SA-(La+Lk) ···(6)

[0083] For example, the effective diameter D of the objective lens 51 is determined from the keratin ring pattern radius H as the diameter of the scan range (scan diameter) required for scanning the scan range SA in the objective lens 51. In some embodiments, known data such as standard eye data or a model eye is used for the distances Le and La. In some embodiments, the distance Lk is known data in the ophthalmic apparatus 1000. In some embodiments, the distance Lk is approximately zero.

[0084] This makes it possible to compare the results obtained from OCT measurements with existing standard data and to utilize the existing standard data to assist in making useful judgments about the OCT measurement results.

[0085] For example, to scan the scan range required for analysis using standard data, the scan range SA is (6×√2) millimeters, (9×√2) millimeters, or (12×√2) millimeters.

[0086] In some embodiments, the ophthalmic apparatus 1000 can set a working distance corresponding to a scan range selected from a plurality of scan ranges and perform OCT measurement at the set working distance. The working distance corresponding to the scan range may be calculated each time according to formula (6) or may be obtained in advance.

[0087] As described above, when performing OCT measurement, by setting the working distance WDoct shown in formula (6), it is possible to obtain scan results that are useful for analysis using standard data. As a result, it is possible to provide an ophthalmic device with a simple configuration that can utilize existing standard data to assist in useful judgment of OCT measurement results.

[0088] As described above, the ophthalmic apparatus 1000 moves the optical system in the Z direction relative to the subject's eye E so that the working distance is WDref when performing reflex measurement, and moves the optical system in the Z direction relative to the subject's eye E so that the working distance is WDref when performing OCT measurement. At this time, in the ophthalmic apparatus 1000, it is desirable to control the fixation projection system 4 and the anterior eye observation system 5 in conjunction with switching between reflex measurement and OCT measurement.

[0089] In the fixation projection system 4, when performing reflex measurement, a target for reflex measurement (e.g., a landscape chart) is projected onto the subject's eye E, and when performing OCT measurement, a target having a narrower visual angle than the target for reflex measurement (e.g., a dot target or a cross target) is projected onto the subject's eye E. In the anterior eye observation system 5, when performing reflex measurement, a relay lens 56 is moved to a position on the optical axis for reflex measurement (first lens position), and when performing OCT measurement, the relay lens 56 is moved to a position on the optical axis for OCT measurement (second lens position).

[0090] <Processing system configuration> The following describes the configuration of the processing system of the ophthalmic apparatus 1000. An example of the functional configuration of the processing system of the ophthalmic apparatus 1000 is shown in Fig. 5. Fig. 5 shows an example of a functional block diagram of the processing system of the ophthalmic apparatus 1000.

[0091] The processing unit 9 controls each unit of the ophthalmologic apparatus 1000. The processing unit 9 can also execute various types of arithmetic processing. The processing unit 9 includes a processor. The functions of the processor are realized by a circuit such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), or 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 processing unit 9 realizes the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or a storage device.

[0092] The processing unit 9 includes a control unit 210 and an arithmetic processing unit 220. The ophthalmic apparatus 1000 also includes a moving mechanism 200, a display unit 270, an operation unit 280, and a communication unit 290.

[0093] The moving mechanism 200 is a mechanism for moving the head unit, which houses optical systems such as the Z alignment system 1, the XY alignment system 2, the keratometry system 3, the fixation projection system 4, the anterior eye observation system 5, the reflex measurement projection system 6, the reflex measurement light receiving system 7, and the OCT optical system 8, in the forward / backward and left / right directions. For example, the moving mechanism 200 is provided with an actuator that generates a driving force for moving the head unit, and a transmission mechanism that transmits this driving force. The actuator is, for example, a pulse motor. The transmission mechanism is, for example, a combination of gears or a rack and pinion. The control unit 210 (main control unit 211) controls the moving mechanism 200 by sending a control signal to the actuator.

[0094] (Control unit 210) The control unit 210 includes a processor and controls each unit of the ophthalmic apparatus. The control unit 210 includes a main control unit 211 and a storage unit 212. The storage unit 212 stores in advance computer programs for controlling the ophthalmic apparatus. The computer programs include a light source control program, a detector control program, an optical scanner control program, an optical system control program, an arithmetic processing program, and a user interface program. The main control unit 211 operates according to such computer programs, and the control unit 210 executes control processing.

[0095] The main control unit 211 performs various controls of the ophthalmic apparatus as a measurement control unit. The control of the Z alignment system 1 includes the control of the Z alignment light source 11 and the control of the line sensor 13. The control of the Z alignment light source 11 includes turning on and off the light source, adjusting the amount of light, and adjusting the aperture. The control of the line sensor 13 includes adjusting the exposure, gain, and detection rate of the detection element. This causes the Z alignment light source 11 to be switched on and off, and the amount of light to be changed. The main control unit 211 captures a signal detected by the line sensor 13, and specifies the projection position of light on the line sensor 13 based on the captured signal. When performing reflex measurement, the main control unit 211 uses the projection position specified by the Z alignment system 1 to determine the position of the corneal apex of the subject's eye E, and controls the moving mechanism 200 based on this to move the head unit in the forward and backward directions (Z alignment). Furthermore, when performing OCT measurement, the main controller 211 manually or automatically moves the head unit in the forward and backward directions using the movement mechanism 200 based on the detection result of the interference light obtained by the OCT optical system 8 (described later).

[0096] The control of the XY alignment system 2 includes the control of the XY alignment light source 21. The control of the XY alignment light source 21 includes turning on and off the light source, adjusting the amount of light, and adjusting the aperture. This causes the XY alignment light source 21 to be switched on and off, or the amount of light to be changed. The main control unit 211 captures a signal detected by the imaging element 59, and specifies the position of a bright spot image based on the return light from the XY alignment light source 21 based on the captured signal. The main control unit 211 controls the moving mechanism 200 to move the head unit in the left / right and up / down directions so that the displacement of the position of the bright spot image Br relative to a predetermined target position (for example, the center position of the alignment mark AL) is canceled (XY alignment).

[0097] The control of the keratometry system 3 includes control of the keratometry light source 32. The control of the keratometry light source 32 includes turning on and off the light source, adjusting the light amount, and adjusting the aperture. As a result, the keratometry light source 32 is switched between on and off, and the light amount is changed. The main controller 211 causes the calculation processor 220 to execute a known calculation on the keratometry image detected by the imaging element 59. As a result, the corneal shape parameters of the subject's eye E are obtained.

[0098] The control of the fixation projection system 4 includes the control of the liquid crystal panel 41 and the movement control of the fixation unit 40. The control of the liquid crystal panel 41 includes the turning on and off of the display of the fixation target, the switching of the fixation target according to the type of examination or measurement, the switching of the display position of the fixation target, etc.

[0099] Fig. 6A is an explanatory diagram of a fixation target according to a first presentation example of the embodiment. Fig. 6A is a schematic diagram of the fixation target according to the first presentation example.

[0100] The main controller 211 displays the fixation target FT1 shown in FIG. 6A on the liquid crystal panel 41 when performing reflex measurement, and displays the fixation target FT2 or FT3 shown in FIG. 6A on the liquid crystal panel 41 when performing OCT measurement. The fixation target FT1 is a landscape chart. The fixation target FT2 is a bright spot (dot target) with a smaller visual angle than the fixation target FT1. The fixation target FT3 is a cross target with a smaller visual angle than the fixation target FT1. In the first presentation example, the main controller 211 switches between the fixation target FT1 and the fixation target FT2 depending on the examination mode (measurement mode). The main controller 211 can also switch between the fixation target FT1 and the fixation target FT3 depending on the examination mode.

[0101] The inspection modes according to this embodiment include, for example, a reflex measurement mode, an OCT measurement mode, and a mode in which reflex measurement is performed and then automatically shifted to OCT measurement.

[0102] In this way, by changing the fixation target displayed on the liquid crystal panel 41 according to the examination mode, in reflex measurement, the fixation target can be presented so as not to cause the test eye to adjust its vision, and in OCT measurement, the fixation target can be presented so as to position the desired part of the test eye at a specified measurement position according to the measurement part, etc.

[0103] Fig. 6B is an explanatory diagram of a fixation target according to the second presentation example of the embodiment. Fig. 6B is a schematic diagram of the fixation target according to the second presentation example.

[0104] The main controller 211 displays the fixation target FT4 shown in FIG. 6B on the liquid crystal panel 41 when performing the reflex measurement, and displays the fixation target BP1 shown in FIG. 6B on the liquid crystal panel 41 so as to be superimposed on the fixation target FT4 when performing the OCT measurement. The fixation target FT4 is a landscape chart similar to the fixation target FT1 shown in FIG. 6A. The fixation target BP1 is a bright spot (dot target) with a smaller visual angle than the fixation target FT4. In the second presentation example, the main controller 211 displays the fixation target BP1 on the fixation target FT4 according to the examination mode (measurement mode). The main controller 211 can blink the fixation target BP1 or move the display position of the fixation target BP1. In some embodiments, the main controller 211 increases the luminance of a part of the fixation target FT4 or periodically increases and decreases the luminance of a part of the fixation target FT4 when performing the OCT measurement. In some embodiments, the fixation target FT3 shown in FIG. 6A is presented instead of the fixation target BP1.

[0105] In the second presentation example, as in the first presentation example, in the reflex measurement, a fixation target can be presented so as not to allow the test eye to adjust its vision, and in the OCT measurement, a fixation target can be presented so as to position a desired part of the test eye at a specified measurement position depending on the measurement part, etc.

[0106] 5, for example, the fixation projection system 4 is provided with a moving mechanism that moves the liquid crystal panel 41 (or the fixation unit 40) in the optical axis direction. This moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism, and a transmission mechanism that transmits the driving force, similar to the moving mechanism 200. The main controller 211 controls the moving mechanism by sending a control signal to the actuator, and moves at least the liquid crystal panel 41 in the optical axis direction. Thereby, the position of the liquid crystal panel 41 is adjusted so that the liquid crystal panel 41 and the fundus Ef are optically conjugate with each other.

[0107] The control of the anterior eye observation system 5 includes the control of the anterior eye illumination light source 50, the control of the lens moving mechanism 56D that moves the relay lens 56, and the control of the image sensor 59. The control of the anterior eye illumination light source 50 includes the turning on and off of the light source, the light amount adjustment, and the aperture adjustment. As a result, the anterior eye illumination light source 50 is switched between on and off, and the light amount is changed. The lens moving mechanism 56D is provided with an actuator that generates a driving force for moving the moving mechanism, and a transmission mechanism that transmits the driving force, similar to the moving mechanism 200. The main control unit 211 controls the lens moving mechanism 56D by sending a control signal to the actuator according to the examination mode (measurement mode), and moves the relay lens 56 in the optical axis direction. For example, the memory unit 212 stores information corresponding to the position on the optical axis of the relay lens 56 in association with the examination mode. The main control unit 211 refers to the information stored in the memory unit 212 and moves the relay lens 56 to a position on the optical axis corresponding to the examination mode. As a result, even if the working distance is changed according to the examination mode, it becomes possible to form an image of the signal from the anterior eye segment on the imaging surface of the image sensor 59, and it becomes possible to observe a focused image of the anterior eye segment even during reflex measurement and OCT measurement. The control of the image sensor 59 includes exposure adjustment, gain adjustment, detection rate adjustment, etc. of the image sensor 59. The main controller 211 takes in the signal detected by the image sensor 59, and causes the calculation processor 220 to execute processing such as forming an image based on the taken in signal.

[0108] The control of the reflex measurement projection system 6 includes control of the reflex measurement light source 61 and control of the rotary prism 66. The control of the reflex measurement light source 61 includes turning on and off the light source, adjusting the light amount, and the like. Thereby, the reflex measurement light source 61 is switched between on and off, and the light amount is changed. For example, the reflex measurement projection system 6 includes a moving mechanism that moves the reflex measurement light source 61 in the optical axis direction. This moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism, and a transmission mechanism that transmits this driving force, similar to the moving mechanism 200. The main control unit 211 controls the moving mechanism by sending a control signal to the actuator, and moves the reflex measurement light source 61 in the optical axis direction. The control of the rotary prism 66 includes rotation control of the rotary prism 66. For example, a rotation mechanism that rotates the rotary prism 66 is provided, and the main control unit 211 rotates the rotary prism 66 by controlling this rotation mechanism.

[0109] The control of the reflex measurement light receiving system 7 includes the control of the focusing lens 74. The control of the focusing lens 74 includes the movement control of the focusing lens 74 in the optical axis direction. For example, the reflex measurement light receiving system 7 includes a moving mechanism that moves the focusing lens 74 in the optical axis direction. This moving mechanism is provided with an actuator that generates a driving force for moving the moving mechanism and a transmission mechanism that transmits the driving force, similar to the moving mechanism 200. The main control unit 211 controls the moving mechanism by sending a control signal to the actuator, and moves the focusing lens 74 in the optical axis direction. The main control unit 211 can move the reflex measurement light source 61 and the focusing lens 74 in the optical axis direction, for example, according to the refractive power of the subject's eye E, so that the reflex measurement light source 61, the fundus Ef, and the image sensor 59 are optically conjugate with each other.

[0110] Control of the OCT optical system 8 includes control of the OCT light source 101, control of the optical scanner 88, control of the focusing lens 87, control of the corner cube 114, control of the detector 125, control of the DAQ 130, etc. Control of the OCT light source 101 includes turning the light source on and off, adjusting the light amount, adjusting the aperture, etc. Control of the optical scanner 88 includes control of the scanning position, scanning range or scanning speed by the first galvanometer mirror, and control of the scanning position, scanning range or scanning speed by the second galvanometer mirror, etc.

[0111] The control of the focusing lens 87 includes movement control of the focusing lens 87 in the optical axis direction, movement control of the focusing lens 87 to a focusing reference position corresponding to the imaging site, and movement control within a movement range (focusing range) corresponding to the imaging site. For example, the OCT optical system 8 includes a movement mechanism that moves the focusing lens 87 in the optical axis direction. This movement mechanism is provided with an actuator that generates a driving force for moving the movement mechanism and a transmission mechanism that transmits the driving force, similar to the movement mechanism 200. The main control unit 211 controls the movement mechanism by sending a control signal to the actuator, and moves the focusing lens 87 in the optical axis direction. In some embodiments, the ophthalmic device is provided with a holding member that holds the focusing lenses 74 and 87, and a driving unit that drives the holding member. The main control unit 211 controls the movement of the focusing lenses 74 and 87 by controlling the driving unit. For example, the main control unit 211 may move the focusing lens 87 in conjunction with the movement of the focusing lens 74, and then move only the focusing lens 87 based on the intensity of the interference signal.

[0112] The control of the corner cube 114 includes, for example, movement control of the corner cube 114 along the optical path. For example, the OCT optical system 8 includes a movement mechanism that moves the corner cube 114 in a direction along the optical path. This movement mechanism is provided with an actuator that generates a driving force for moving the movement mechanism and a transmission mechanism that transmits the driving force, similar to the movement mechanism 200. The main control unit 211 controls the movement mechanism by sending a control signal to the actuator, and moves the corner cube 114 in a direction along the optical path. The control of the detector 125 includes exposure adjustment, gain adjustment, detection rate adjustment, and the like of the detection element. The main control unit 211 samples the signal detected by the detector 125 using the DAQ 130, and causes the calculation processing unit 220 (image forming unit 222) to execute processing such as forming an image based on the sampled signal.

[0113] Furthermore, the main control unit 211 performs processing for writing data to the storage unit 212 and processing for reading data from the storage unit 212 .

[0114] (Storage unit 212) The storage unit 212 stores various types of data. Examples of the data stored in the storage unit 212 include objective measurement results, image data of a tomographic image, image data of a fundus image, control information referred to by the main controller 211 (for example, lens position information of the relay lens 56), and information on the subject's eye. The information on the subject's eye includes information on the subject, such as a patient ID and name, and information on the subject's eye, such as identification information of the left eye / right eye. The storage unit 212 also stores various programs and data for operating the ophthalmologic apparatus.

[0115] (Calculation processing unit 220) The arithmetic processing unit 220 includes an eye refractive power calculation unit 221 , an image formation unit 222 , and a data processing unit 223 .

[0116] The ocular refractive power calculation unit 221 analyzes a ring image (pattern image) obtained by receiving, by the imaging element 59, the return light of a ring-shaped light beam (ring-shaped measurement pattern) projected onto the fundus Ef by the reflex measurement projection system 6. For example, the ocular refractive power calculation unit 221 obtains the center of gravity of the ring image from the luminance distribution in the image in which the obtained ring image is depicted, obtains the luminance distribution along a plurality of scanning directions extending radially from the center of gravity, and identifies the ring image from the luminance distribution. Next, the ocular refractive power calculation unit 221 obtains an ellipse approximation of the identified ring image, and obtains the spherical power, the cylindrical power, and the cylindrical axis angle by substituting the major axis and minor axis of the ellipse into a known formula. Alternatively, the ocular refractive power calculation unit 221 can obtain parameters of the ocular refractive power based on the deformation and displacement of the ring image relative to the reference pattern.

[0117] Moreover, the eye refractive power calculation unit 221 calculates the corneal refractive power, the degree of corneal astigmatism, and the corneal astigmatism axis angle based on the keratinizing image acquired by the anterior eye observation system 5. For example, the eye refractive power calculation unit 221 calculates the corneal radii of curvature of the principal meridian and the principal meridian of the anterior cornea by analyzing the keratinizing image, and calculates the above parameters based on the corneal radii of curvature.

[0118] The image forming unit 222 forms image data of a tomographic image of the fundus oculi Ef based on the signal detected by the detector 115. That is, the image forming unit 222 forms image data of the subject's eye E based on the detection result of the interference light LC by the interference optical system. This processing includes filtering, FFT (Fast Fourier Transform), and other processing, as in conventional spectral domain type OCT. The image data acquired in this manner is a data set including a group of image data formed by imaging the reflection intensity profiles in multiple A-lines (paths of each measurement light LS in the subject's eye E).

[0119] To improve image quality, multiple data sets collected by repeating the same pattern scan multiple times can be superimposed (averaged).

[0120] The data processing unit 223 performs various data processing (image processing) and analysis processing on the tomographic image formed by the image forming unit 222. For example, the data processing unit 223 executes correction processing such as brightness correction and dispersion correction of the image. In addition, the data processing unit 223 performs various image processing and analysis processing on the image (anterior eye image, etc.) obtained using the anterior eye observation system 5.

[0121] An example of the analysis process is a process of specifying the position (position in the Z direction, depth position) of a predetermined part of the subject's eye E. That is, the data processing unit 223, as an analysis unit, is capable of specifying the position of a predetermined part of the subject's eye E based on the detection result of the interference light LC obtained by the OCT optical system 8. The predetermined part includes a part including an area corresponding to the cornea, a part including an area corresponding to the retina, and the like.

[0122] For example, the data processing unit 223 identifies the position of a specific part in the Z direction based on the detection intensity of the interference light LC (the intensity of the detection signal (interference signal) corresponding to the detection result). For example, the data processing unit 223 identifies the part corresponding to the position where the detection intensity of the interference light LC is maximum as the position of the part corresponding to the cornea. Also, for example, the data processing unit 223 identifies the part corresponding to the position where the detection intensity of the interference light LC is second highest after the cornea as the position of the part corresponding to the retinal pigment epithelium layer, and identifies the position of the part corresponding to the retina based on the identified position.

[0123] Alternatively, the data processing unit 223 specifies the position of the predetermined part in the Z direction based on the tomographic image formed by the image forming unit 222 based on the detection result of the interference light LC. For example, the data processing unit 223 specifies a layer structure in the tomographic image formed by the image forming unit 222, and specifies the position of the part corresponding to the cornea based on the shape of the specified layer structure. Also, for example, the data processing unit 223 performs segmentation processing on the tomographic image formed by the image forming unit 222, and specifies the position of the part corresponding to the retina (retinal pigment epithelium layer, etc.) by analyzing the obtained tomographic image of the retina.

[0124] The data processing unit 223 can perform known image processing such as an interpolation process for interpolating pixels between tomographic images to form volume data (voxel data) of the subject's eye E. When an image based on the volume data is to be displayed, the data processing unit 223 performs a rendering process on the volume data to form a pseudo three-dimensional image as viewed from a specific line of sight.

[0125] (Display section 270, operation section 280) The display unit 270 serves as a user interface unit and displays information under the control of the control unit 210. The display unit 270 includes the display unit 10 shown in FIG.

[0126] The operation unit 280 is used as a user interface unit to operate the ophthalmic apparatus. The operation unit 280 includes various hardware keys (joystick, button, switch, etc.) provided in the ophthalmic apparatus. The operation unit 280 may also include various software keys (buttons, icons, menus, etc.) displayed on the touch panel type display screen 10a.

[0127] At least a part of the display unit 270 and the operation unit 280 may be integrally configured. A typical example of such an integral configuration is a touch panel type display screen 10a.

[0128] (Communication unit 290) The communication unit 290 has a function for communicating with an external device (not shown). The communication unit 290 has a communication interface according to a connection form with the external device. An example of the external device is a spectacle lens measuring device for measuring optical characteristics of a lens. The spectacle lens measuring device measures the diopter of the spectacle lens worn by the subject, and inputs the measurement data to the ophthalmic device 1000. The external device may be any ophthalmic device, 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 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, or the like. The communication unit 290 may be provided in the processing unit 9, for example.

[0129] The refraction measurement projection system 6 and the refraction measurement light receiving system 7 are an example of a "refractive power measurement optical system" according to the embodiment. The OCT optical system 8 is an example of an "inspection optical system" according to the embodiment. The working distance WDref is an example of a "first working distance" according to the embodiment. The working distance WDoct is an example of a "second working distance" according to the embodiment. The Z alignment system 1 is an example of an "alignment optical system that irradiates alignment light to the test eye from a direction different from the optical axis direction of the objective lens" according to the embodiment. The data processing unit 223 is an example of an "analysis unit" according to the embodiment.

[0130] <Example of operation> The operation of the ophthalmologic apparatus 1000 according to the embodiment will be described.

[0131] Fig. 7 shows an example of the operation of the ophthalmic apparatus 1000. Fig. 7 shows a flow diagram of an example of the operation of the ophthalmic apparatus 1000 when performing OCT measurement after reflex measurement. The storage unit 212 stores a computer program for realizing the processing shown in Fig. 7. The main control unit 211 operates according to this computer program to execute the processing shown in Fig. 7.

[0132] (S1: Lens movement) When the examiner performs a predetermined operation on the operation unit 280 with the subject's face fixed on a face receiving unit (not shown), the main controller 211 controls the lens moving mechanism 56D to move the relay lens 56 to a lens position for reflex measurement on the optical axis of the anterior eye observation system 5. In some embodiments, the main controller 211 refers to control information stored in advance in the storage unit 212 and controls the lens moving mechanism 56D based on lens position information stored in association with the reflex measurement mode set before step S1.

[0133] (S2: Alignment) Next, main controller 211 executes alignment. In step S2, Z alignment is performed using Z alignment system 1.

[0134] Specifically, the main controller 211 turns on the Z alignment light source 11 and the XY alignment light source 21. The main controller 211 also turns on the anterior eye illumination light source 50. The processor 9 acquires an imaging signal of an anterior eye image on the imaging surface of the imaging element 59, and displays the anterior eye image on the display unit 270. After that, the optical system shown in FIG. 1 is moved to an examination position of the subject's eye E. The examination position is a position where the examination of the subject's eye E can be performed with sufficient accuracy. The subject's eye E is placed at the examination position through the above-mentioned alignment (alignment by the Z alignment system 1, the XY alignment system 2, and the anterior eye observation system 5). The movement of the optical system is executed by the controller 210 according to an operation or instruction by the user or an instruction by the controller 210. That is, the optical system is moved to the examination position of the subject's eye E, and preparations are made for objective measurement. In addition, this alignment is performed at any time until the refraction measurement (refractive power measurement) is completed.

[0135] Furthermore, the main control unit 211 moves the reflector measurement light source 61, the focusing lens 74, and the liquid crystal panel 41 to the origin position (for example, a position corresponding to 0D) along their respective optical axes.

[0136] (S3: Kerato measurement) Next, the main controller 211 causes the liquid crystal panel 41 to display a fixation target FT1 (landscape chart) shown in FIG. 6A.

[0137] After that, the main controller 211 turns on the keratometer ring light source 32. When light is output from the keratometer ring light source 32, a ring-shaped light beam for corneal shape measurement is projected onto the cornea Cr of the subject's eye E. The eye refractive power calculator 221 performs arithmetic processing on the image acquired by the image sensor 59 to calculate the corneal curvature radius, and calculates the corneal refractive power, the corneal astigmatism degree, and the corneal astigmatism axis angle from the calculated corneal curvature radius. In the controller 210, the calculated corneal refractive power and the like are stored in the memory 212. In response to an instruction from the main controller 211 or an operation or instruction from the user to the operation unit 280, the operation of the ophthalmic device 1000 proceeds to step S4. Note that the keratometer measurement may be performed simultaneously or continuously when a ring image is acquired in the next reflective measurement. Also, the keratometer ring light source 32 may be kept on during all measurements.

[0138] (S4: Refractive power measurement) Next, the main controller 211 executes the refractive power measurement.

[0139] In the reflex measurement, the main controller 211 projects a ring-shaped measurement pattern light beam for the reflex measurement onto the subject's eye E as described above. A ring image based on the return light of the measurement pattern light beam from the subject's eye E is formed on the imaging surface of the imaging element 59. The main controller 211 determines whether or not a ring image based on the return light from the fundus Ef detected by the imaging element 59 has been acquired. For example, the main controller 211 detects the position (pixel) of the edge of the image based on the return light detected by the imaging element 59, and determines whether or not the width of the image (difference between the outer diameter and the inner diameter) is equal to or greater than a predetermined value. Alternatively, the main controller 211 may determine whether or not a ring image has been acquired by determining whether or not a ring can be formed based on points (images) that are equal to or greater than a predetermined height (ring diameter).

[0140] When it is determined that the ring image has been acquired, the eye refractive power calculation unit 221 analyzes the ring image based on the return light of the measurement pattern light beam projected on the eye E by a known method, and obtains a provisional spherical power S and provisional cylindrical power C. Based on the obtained provisional spherical power S and cylindrical power C, the main control unit 211 moves the reflex measurement light source 61, the focusing lens 74, and the liquid crystal panel 41 to a position of equivalent spherical power (S+C / 2) (a position corresponding to a provisional far point). After this, the ring image is acquired again, analyzed, and a provisional spherical power S and provisional cylindrical power C are obtained, and the ring image is moved from the position moved in the first measurement to perform fine adjustment. The main control unit 211 further moves the liquid crystal panel 41 from that position to a cloudy position, and then controls the reflex measurement projection system 6 and the reflex measurement light receiving system 7 to acquire a ring image again as the main measurement. The main controller 211 causes the ocular refractive power calculator 221 to calculate the spherical power, the cylindrical power, and the cylindrical axis angle from the analysis result of the obtained ring image and the amount of movement of the focusing lens 74 in the same manner as described above.

[0141] Further, the eye refractive power calculation unit 221 calculates a position corresponding to the far point of the subject's eye E (a position corresponding to the far point obtained by this measurement) from the calculated spherical power and cylindrical power. The main control unit 211 moves the liquid crystal panel 41 to the position corresponding to the calculated far point. In the control unit 210, the position of the focusing lens 74 and the calculated spherical power, etc. are stored in the storage unit 212. In response to an instruction from the main control unit 211 or an operation or instruction from the user to the operation unit 280, the operation of the ophthalmic apparatus 1000 proceeds to step S5.

[0142] When it is determined that the ring image cannot be acquired, the main controller 211, taking into consideration the possibility that the patient has a severe refractive error, moves the reflex measurement light source 61 and the focusing lens 74 to the negative power side (e.g., -10D) and the positive power side (e.g., +10D) in a preset step. The main controller 211 controls the reflex measurement light receiving system 7 to detect the ring image at each position. When it is still determined that the ring image cannot be acquired, the main controller 211 executes a predetermined measurement error process. At this time, the operation of the ophthalmic device 1000 may proceed to step S5. In the controller 210, information indicating that the reflex measurement result was not obtained is stored in the memory unit 212.

[0143] That is, Z alignment (first control step) is performed in step S2, and reflex measurement (first measurement step) is performed in step S4. In the reflex measurement in step S4, a fixation target for reflex measurement is projected (first projection step). Furthermore, before the reflex measurement in step S4, a relay lens is moved to a position for reflex measurement (first lens movement step).

[0144] (S5: OCT measurement?) Next, the main controller 211 determines whether or not to perform OCT measurement. For example, the main controller 211 determines whether or not to perform OCT measurement by determining whether or not a predetermined operation has been performed on the operation unit 280. In some embodiments, the main controller 211 determines whether or not to perform OCT measurement based on the inspection mode set before step S1.

[0145] When it is determined that the OCT measurement is to be performed (S5: Y), the operation of the ophthalmic apparatus 1000 proceeds to step S6. When it is determined that the OCT measurement is not to be performed (S5: N), the operation of the ophthalmic apparatus 1000 ends (END).

[0146] (S6: Lens movement) When it is determined in step S5 that the OCT measurement is to be performed (S5: Y), the main controller 211 controls the lens moving mechanism 56D to move the relay lens 56 to a lens position for OCT measurement on the optical axis of the anterior eye observation system 5. In some embodiments, the main controller 211 refers to control information stored in advance in the storage unit 212 and controls the lens moving mechanism 56D based on lens position information stored in association with the examination mode set before step S1.

[0147] (S7: Fixation target switching) 6A on the liquid crystal panel 41. As a result, the fixation target FT2 or FT3 is presented to the subject's eye E.

[0148] (S8: OCT focusing lens movement) Next, the main controller 211 moves the focusing lens 87 to a position corresponding to the refractive power measurement result obtained in step S4. In some embodiments, the focusing lens 87 of the OCT optical system 8 is moved in the optical axis direction in conjunction with the movement of the reflex measurement light source 61 and the focusing lens 74. In some embodiments, the storage unit 212 stores control information associated with lens position information of the focusing lens 87 for moving the focal position of the measurement light LS to a predetermined site (cornea or retina) of the subject's eye in accordance with the refractive power measurement result. The main controller 211 moves the focusing lens 87 by referring to the control information stored in the storage unit 212, thereby moving the focal position of the measurement light LS to a predetermined site of the subject's eye E.

[0149] (S9: OCT provisional measurement) Next, the main controller 211 controls the OCT optical system 8 to execute the OCT provisional measurement.

[0150] Specifically, the main controller 211 turns on the OCT light source 101 and controls the optical scanner 88 to scan a predetermined portion (e.g., the cornea) of the subject's eye E with the measurement light LS. For example, a detection signal obtained by scanning with the measurement light LS is sent to the image forming unit 222. The image forming unit 222 forms a tomographic image (OCT image) of the subject's eye E from the obtained detection signal.

[0151] (S10: Shows OCT image) Next, the main controller 211 causes the display unit 270 to display the tomographic image of the subject's eye E formed in step S9 as an OCT image.

[0152] (S11: Accept alignment operation) Thereafter, the main controller 211 accepts an alignment operation for moving the optical system relatively to the subject's eye E. While referring to the OCT image displayed in step S10, the user performs a predetermined alignment operation on the operation unit 280 so that the position of a predetermined part of the subject's eye E (for example, the cornea) falls within a predetermined range. The main controller 211 controls the movement mechanism 200 based on the user's operation on the operation unit 280, thereby moving the optical system relatively to the subject's eye E. Thus, Z alignment is performed.

[0153] In some embodiments, step S9 and step S10 are repeatedly executed, whereby the display unit 270 displays live a tomographic image of a predetermined portion of the subject's eye E obtained by the OCT provisional measurement.

[0154] In some embodiments, in step S11, the main controller 211 turns on the XY alignment light source 21. The main controller 211 also turns on the anterior eye illumination light source 50. The processing unit 9 acquires an imaging signal of an anterior eye image on the imaging surface of the imaging element 59, and causes the display unit 270 to display the anterior eye image. The main controller 211 controls the moving mechanism 200 based on the user's operation on the operation unit 280, thereby moving the optical system in the XY directions relative to the subject's eye E. This executes XY alignment.

[0155] (S12: Alignment complete?) Next, the main controller 211 determines whether the alignment is complete. For example, the main controller 211 determines whether the alignment is complete by determining whether a predetermined operation has been performed on the operation unit 280. In some embodiments, the predetermined operation is an alignment completion operation or an operation for starting the execution of the main OCT measurement.

[0156] When it is determined that the alignment is complete (S12: Y), the operation of the ophthalmic apparatus 1000 proceeds to step S13. When it is determined that the alignment is not complete (S12: N), the operation of the ophthalmic apparatus 1000 proceeds to step S10. In some embodiments, when it is determined that the alignment is not complete (S12: N), the operation of the ophthalmic apparatus 1000 proceeds to step S9.

[0157] (S13: OCT measurement) When it is determined in step S12 that the alignment is completed (S12: Y), the main controller 211 controls the OCT optical system 8 to execute the main OCT measurement.

[0158] Specifically, the main controller 211 turns on the OCT light source 101 and controls the optical scanner 88 to scan a predetermined portion of the subject's eye E with the measurement light LS. For example, a detection signal obtained by scanning with the measurement light LS is sent to the image forming unit 222. The image forming unit 222 forms a tomographic image of the predetermined portion of the subject's eye E from the obtained detection signal. This completes the operation of the ophthalmic apparatus 1000 (END).

[0159] That is, an OCT image is formed in step S9 (image formation step), Z alignment (second control step) is performed in steps S10 to S12, and OCT measurement (second measurement step) is performed in step S13. A fixation target for OCT measurement is projected in step S7 (second projection step). Moreover, a relay lens is moved to a position for OCT measurement in step S6 (second lens movement step).

[0160] As described above, the objective lens 51 is shared between the reflex measurement optical system and the OCT optical system 8, and the working distance is switched between reflex measurement and OCT measurement, so that an ophthalmic device capable of obtaining highly accurate reflex measurement results and highly accurate OCT measurement results with a simple configuration can be provided.

[0161] At this time, Z alignment is performed using the Z alignment system 1 before the REF measurement, and Z alignment is performed manually while referring to the OCT image before the OCT measurement. This makes it possible to perform measurements at the optimal working distance for the REF measurement and the OCT measurement with a very simple configuration.

[0162] In particular, since the working distance is set to the value shown in formula (4) when performing the reflex measurement, it is possible to lengthen the working distance to reduce the effect of instrumental myopia, while preventing the size of the keratopanel 31 from becoming large. This makes it possible to provide an ophthalmic device that can obtain highly accurate reflex or keratopanel measurement results with a simple configuration.

[0163] In addition, when the working distance is automatically set during OCT measurement, the working distance is set to the value shown in formula (6), so that scan results useful for analysis using standard data can be obtained. This makes it possible to provide an ophthalmic device with a simple configuration that can assist in useful judgments on OCT measurement results by utilizing existing standard data. At this time, it is also possible to perform a scan at the positions of the corneal apex and fovea and calculate the axial length.

[0164] In the embodiment, an OCT optical system has been described as an example of an examination optical system having an optical scanner, but the configuration of the ophthalmologic apparatus according to the embodiment is not limited thereto. The examination optical system according to some embodiments includes an SLO optical system. The SLO optical system is an optical system for scanning the fundus Ef with light by an optical scanner and detecting the return light by a light receiving device. In some embodiments, the SLO optical system obtains a front image of the fundus Ef by laser scanning using a confocal optical system. The SLO optical system includes an optical scanner, an SLO projection system that deflects light from an SLO light source by the optical scanner and projects the deflected light onto the subject's eye E, and an SLO light receiving system that receives the return light.

[0165] Even in this case, it is possible to obtain scan results that are useful for analysis using standard data. As a result, it is possible to provide an ophthalmic apparatus with a simple configuration that can assist in making useful decisions about SLO measurement results by utilizing existing standard data.

[0166] [Variations] The configuration of the ophthalmic apparatus 1000 according to the embodiment is not limited to the configuration described in the above embodiment. Hereinafter, the configuration of an ophthalmic apparatus according to a modification of the embodiment will be described, focusing on the differences from the embodiment.

[0167] [First Modification] In the above embodiment, a fixation target suitable for the examination, etc. was presented to the subject eye E by switching the fixation target displayed on the liquid crystal panel 41, but the configuration of the ophthalmic apparatus of the embodiment is not limited to this.

[0168] Fig. 8 shows an example of the configuration of a fixation projection system 4 according to a first modified example of the embodiment. In Fig. 8, the same parts as in Fig. 1 are given the same reference numerals, and the description will be omitted as appropriate.

[0169] The fixation unit 40 provided in the fixation projection system 4 is provided with an illumination light source 45a, a visual target chart 46a, and a fixation light source 47a instead of the liquid crystal panel 41. The fixation light source 47a, the visual target chart 46a, and the relay lens 42 are arranged in this order from the illumination light source 45a toward the dichroic mirror 83. The visual target chart 46a is arranged between the illumination light source 45a and the subject's eye E, and is a transmissive visual target chart on which a landscape chart such as fixation targets FT1 and FT4 is displayed. In some embodiments, the visual target chart 46a is a transmissive film on which a landscape chart is printed. In some embodiments, the fixation light source 47a is a point light source having a predetermined light emission size.

[0170] The main controller 211 turns on the illumination light source 45a when performing reflex measurement, and projects a landscape chart (first fixation target) onto the subject's eye E by illuminating the target chart 46a with light from the illumination light source 45a. The main controller 211 also turns on the fixation light source 47a when performing OCT measurement, and projects a bright spot (dot target) (second fixation target) onto the subject's eye E. In some embodiments, the main controller 211 turns off the fixation light source 47a when performing reflex measurement, and turns off the illumination light source 45a when performing OCT measurement. Thereby, a landscape chart is presented to the subject's eye E when performing reflex measurement, and a bright spot is presented to the subject's eye E when performing OCT measurement.

[0171] In some embodiments, the fixation light source 47a is blinked when performing OCT measurement. In some embodiments, a plurality of fixation light sources 47a are provided, and the main controller 211 selectively turns on the plurality of fixation light sources 47a to change or move the projection position of the bright spot. In some embodiments, the main controller 211 turns on some or all of the plurality of fixation light sources 47a to change the size of the bright spot.

[0172] [Second Modification] Fig. 9 shows an example of the configuration of a fixation projection system 4 according to a second modified example of the embodiment. In Fig. 9, the same parts as those in Fig. 1 or 8 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0173] The fixation unit 40 provided in the fixation projection system 4 is provided with an illumination light source 45a, a half mirror 48b, a visual target chart 46a, a fixation light source 47a, and a relay lens 49b instead of the liquid crystal panel 41. The half mirror 48b combines the optical path of the light from the illumination light source 45a and the optical path of the light from the fixation light source 47a. The half mirror 48b, the visual target chart 46a, and the relay lens 42 are arranged in this order from the illumination light source 45a toward the dichroic mirror 83. The relay lens 49b, the half mirror 48b, the visual target chart 46a, and the relay lens 42 are arranged in this order from the fixation light source 47a toward the dichroic mirror 83. The visual target chart 46a is arranged in the optical path combined by the half mirror 48b, and is a transmissive visual target chart on which a landscape chart such as fixation targets FT1 and FT4 is displayed. The visual target chart 46a is arranged at the focal position of the relay lens 49b.

[0174] The light from the illumination light source 45a passes through the half mirror 48b, passes through the optotype chart 46a, passes through the relay lens 42, and is guided to the dichroic mirror 83. The light from the fixation light source 47a passes through the relay lens 49b, is reflected by the half mirror 48b, passes through the optotype chart 46a, passes through the relay lens 42, and is guided to the dichroic mirror 83.

[0175] When performing reflex measurement, the main controller 211 turns on the illumination light source 45a and illuminates the target chart 46a with light from the illumination light source 45a, thereby projecting a landscape chart (first fixation target) onto the subject's eye E. When performing OCT measurement, the main controller 211 turns on the fixation light source 47a to project a bright spot (dot target) (second fixation target) onto the subject's eye E. At this time, the light from the fixation light source 47a is condensed at a predetermined position on the target chart 46a, forming a bright spot.

[0176] In some embodiments, the main controller 211 turns off the fixation light source 47a when performing the reflex measurement, and turns off the illumination light source 45a when performing the OCT measurement. Thereby, a landscape chart is presented to the subject's eye E when performing the reflex measurement, and a bright point is presented to the subject's eye E when performing the OCT measurement.

[0177] As described above, by providing a transmissive target chart 46a displaying a landscape chart and controlling the illumination light source 45a and the fixation light source 47a according to the examination mode, in reflex measurement, a fixation target can be presented so as not to cause the subject's eye to adjust its vision, and in OCT measurement, a fixation target can be presented so as to position a desired part of the subject's eye at a predetermined measurement position according to the measurement part, etc.

[0178] [Third Modification] In the above embodiment or its variant, a case has been described in which a single target chart is used to project a fixation target during reflex measurement and OCT measurement, but the configuration of the ophthalmologic apparatus according to the embodiment is not limited to this.

[0179] Fig. 10 shows an example of the configuration of a fixation projection system 4 according to a third modified example of the embodiment. In Fig. 10, the same parts as in Fig. 1 are given the same reference numerals, and the description will be omitted as appropriate.

[0180] The fixation projection system 4 includes a first fixation projection system for projecting a landscape chart onto the subject's eye E, and a second fixation projection system for projecting a bright spot (dot target, cross target) having a smaller visual angle than the landscape chart onto the subject's eye E. The optical path of the first fixation projection system and the optical path of the second fixation projection system are connected by a half mirror 49c. The first fixation projection system includes an illumination light source 45c and a transmissive target chart 46c. The second fixation projection system includes an illumination light source 47c and a transmissive target chart 48c.

[0181] The optotype chart 46c is disposed between the illumination light source 45c and the subject's eye E, and is a transmissive optotype chart on which a landscape chart such as fixation targets FT1 and FT4 is displayed. In some embodiments, the optotype chart 46c is a transmissive film on which a landscape chart is printed. The optotype chart 48c is disposed between the illumination light source 47c and the subject's eye E, and is a transmissive optotype chart on which dot optotypes or cross optotypes such as fixation targets FT2 and FT3 are displayed. In some embodiments, the optotype chart 48c is a transmissive film on which a dot optotype or cross optotype is printed.

[0182] The main controller 211 controls the first fixation projection system and the second fixation projection system to project at least one of a landscape chart and a bright spot (dot target, cross target) onto the subject's eye E. Specifically, the main controller 211 turns on the illumination light source 45c when performing reflex measurement, and projects a landscape chart (first fixation target) onto the subject's eye E by illuminating the target chart 46c with light from the illumination light source 45c. Furthermore, the main controller 211 turns on the illumination light source 47c when performing OCT measurement, and projects a bright spot (dot target, cross target) or a cross target (second fixation target) onto the subject's eye E by illuminating the target chart 48c with light from the illumination light source 47c. In some embodiments, the main controller 211 turns off the illumination light source 47c when performing reflex measurement, and turns off the illumination light source 45c when performing OCT measurement. Thereby, a landscape chart is presented to the subject's eye E when performing the reflex measurement, and a bright point is presented to the subject's eye E when performing the OCT measurement. In some embodiments, the illumination light source 47c is blinked when performing the OCT measurement.

[0183] [Fourth Modification] Fig. 11 shows an example of the configuration of a fixation projection system 4 according to a fourth modified example of the embodiment. In Fig. 11, the same parts as those in Fig. 1 or 10 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0184] 10, the fixation projection system 4 includes a first fixation projection system for projecting a landscape chart onto the subject's eye E, and a second fixation projection system for projecting a bright spot or the like having a smaller visual angle than the landscape chart onto the subject's eye E. The optical path of the first fixation projection system and the optical path of the second fixation projection system are switched by a quick return mirror 49d. That is, the quick return mirror 49d selectively places the first fixation projection system and the second fixation projection system in the optical path of the fixation projection system.

[0185] The main controller 211 controls the quick-return mirror 49d so that the first fixation projection system is disposed in the optical path of the fixation projection system 4 when performing the reflex measurement, turns on the illumination light source 45c, and projects a landscape chart (first fixation target) onto the subject's eye E by illuminating the target chart 46c with the light from the illumination light source 45c. In addition, the main controller 211 controls the quick-return mirror 49d so that the second fixation projection system is disposed in the optical path of the fixation projection system 4 when performing the OCT measurement, turns on the illumination light source 47c, and projects a bright point (dot target, cross target) (second fixation target) onto the subject's eye E by illuminating the target chart 48c with the light from the illumination light source 47c.

[0186] In some embodiments, the main controller 211 turns off the illumination light source 47c when performing the reflex measurement, and turns off the illumination light source 45c when performing the OCT measurement. Thereby, a landscape chart is presented to the subject's eye E when performing the reflex measurement, and a bright point is presented to the subject's eye E when performing the OCT measurement. In some embodiments, the illumination light source 47c is blinked when performing the OCT measurement.

[0187] [Fifth Modification] Instead of the quick-return mirror 49d as the switching mechanism according to the fourth modified example, a moving mechanism for moving the first and second fixation projection systems may be provided. The moving mechanism selectively positions the first and second fixation projection systems in the optical path of the fixation projection system 4 by moving the first and second fixation projection systems.

[0188] For example, the main controller 211 controls the moving mechanism to selectively place the first fixation projection system and the second fixation projection system in the optical path of the fixation projection system 4. That is, the main controller 211 selectively places the illumination light source and the target chart for the reflex measurement and the illumination light source and the target chart for the OCT measurement in the optical path of the fixation projection system 4. When performing the reflex measurement, the main controller 211 controls the moving mechanism so that the first fixation projection system is placed in the optical path of the fixation projection system 4, turns on the illumination light source 45c, and projects a landscape chart (first fixation target) onto the subject's eye E by illuminating the target chart 46c with light from the illumination light source 45c. In addition, the main controller 211 controls the moving mechanism so that the second fixation projection system is placed in the optical path of the fixation projection system 4 when performing the OCT measurement, turns on the illumination light source 47c, and projects a bright point (dot target) or a cross target (second fixation target) onto the subject's eye E by illuminating the target chart 48c with light from the illumination light source 47c.

[0189] In some embodiments, the moving mechanism selectively positions the first fixation projection system and the second fixation projection system in the optical path of the fixation projection system 4 by moving the first fixation projection system and the second fixation projection system in a direction intersecting the optical path of the fixation projection system 4.

[0190] As described above, by providing a transmissive optotype chart 46c showing a landscape chart and a transmissive optotype chart 48c showing a dot optotype or a cross optotype, and controlling the illumination light sources 45a and 47c according to the examination mode, in reflex measurement, a fixation target can be presented so as not to cause the subject's eye to adjust its vision, and in OCT measurement, a fixation target can be presented so as to position a desired part of the subject's eye at a predetermined measurement position according to the measurement part, etc.

[0191] [Sixth Modification] In the above embodiment or its modified example, a case where Z alignment is performed manually before OCT measurement has been described, but the configuration according to the embodiment is not limited to this. Z alignment may be performed automatically before OCT measurement.

[0192] The sixth modified example of the embodiment will be described below, focusing on the differences from the embodiment. The ophthalmic apparatus according to the sixth modified example of the embodiment has a similar configuration to the ophthalmic apparatus 1000 according to the embodiment.

[0193] Fig. 12 shows an example of the operation of the ophthalmic apparatus according to the sixth modified example of the embodiment. Like Fig. 7, Fig. 12 shows a flow diagram of an example of the operation of the ophthalmic apparatus when OCT measurement is performed after reflex measurement. The storage unit 212 stores a computer program for realizing the processing shown in Fig. 12. The main control unit 211 operates according to this computer program to execute the processing shown in Fig. 12.

[0194] (S21: Lens movement) The main controller 211 controls the lens moving mechanism 56D to move the relay lens 56 to a lens position for reflex measurement on the optical axis of the anterior eye observation system 5, in the same manner as in step S1.

[0195] (S22: Alignment) Next, the main controller 211 executes alignment in the same manner as in step S2.

[0196] (S23: Kerato measurement) Next, the main controller 211 causes the liquid crystal panel 41 to display the fixation target FT1 (landscape chart) shown in FIG. 6A, and controls the keratometry system 3 to execute keratometry, similarly to step S3.

[0197] (S24: Refractive power measurement) Next, the main controller 211 executes the refractive power measurement in the same manner as in step S4.

[0198] (S25:OCT measurement?) Next, the main controller 211 determines whether or not to perform OCT measurement, similarly to step S5. When it is determined that OCT measurement is to be performed (S25: Y), the operation of the ophthalmic apparatus proceeds to step S26. When it is determined that OCT measurement is not to be performed (S25: N), the operation of the ophthalmic apparatus ends (END).

[0199] (S26: Lens movement) When it is determined in step S25 that OCT measurement is to be performed (S25:Y), the main control unit 211 controls the lens moving mechanism 56D to move the relay lens 56 to the lens position for OCT measurement on the optical axis of the anterior eye observation system 5, as in step S6.

[0200] (S27: Fixation target switching) Next, the main controller 211 causes the liquid crystal panel 41 to display the dot target or cross target shown in FIG. 6A, in the same manner as in step S7.

[0201] (S28: OCT focusing lens movement) Next, the main controller 211 moves the focusing lens 87 to a position corresponding to the refractive power measurement result obtained in step S24, similar to step S8.

[0202] (S29:OCT provisional measurement) Next, the main controller 211 controls the OCT optical system 8 to execute the OCT provisional measurement, similarly to step S9.

[0203] (S30: Identify the part) Next, the main controller 211 causes the data processor 223 to determine the Z-direction position of a predetermined part of the test eye E (e.g., the cornea) based on the detection result of the interference light LC obtained in step S29. In some embodiments, the data processor 223 determines the Z-direction position of the predetermined part of the test eye E based on the detection intensity of the interference light LC. In some embodiments, the data processor 223 determines the Z-direction position of the predetermined part of the test eye E by analyzing a tomographic image formed based on the detection result of the interference light LC.

[0204] (S31: Within the specified range?) Next, the main controller 211 determines whether the position of the specific part identified in step S30 is within a specific range. For example, the main controller 211 determines whether the position of the specific part in the Z direction is within a specific range. The specific range may be a predetermined range within the A scan range, a predetermined range in the depth direction in the B scan, a focusing range including the focusing position of the measurement light LS, etc.

[0205] In step S31, when it is determined that the position of the identified predetermined part is within a predetermined range (step S31: Y), the operation of the ophthalmic apparatus proceeds to step S33. In step S31, when it is determined that the position of the identified predetermined part is not within the predetermined range (step S31: N), the operation of the ophthalmic apparatus proceeds to step S32.

[0206] (S32: Move the optical system) In step S31, when it is determined that the position of the identified predetermined part is not within the predetermined range (step S31: N), the main controller 211 controls the moving mechanism 200 to move the optical system with respect to the eye E to be examined.

[0207] In some embodiments, the main controller 211 controls the moving mechanism 200 by a predetermined step in a direction corresponding to the position of the predetermined part relative to the range. In some embodiments, the main controller 211 controls the moving mechanism 200 so as to cancel the displacement of the position of the predetermined part relative to a reference position within the predetermined range in step S31. In some embodiments, the main controller 211 controls the moving mechanism 200 so that the position of the predetermined part becomes the working distance WDoct shown in formula (6) within the predetermined range.

[0208] Operation of the ophthalmic apparatus then proceeds to step S30. In some embodiments, operation of the ophthalmic apparatus proceeds to step S29 after step S32.

[0209] In some embodiments, before step S31, an XY alignment is performed.

[0210] (S33: OCT measurement) In step S31, when it is determined that the position of the identified predetermined part is within a predetermined range (step S31: Y), the main controller 211 executes the main OCT measurement by controlling the OCT optical system 8, similarly to step S13. Then, the operation of the ophthalmologic apparatus is completed (END).

[0211] As described above, according to the sixth modified example, it is possible to obtain the same effects as those of the embodiment.

[0212] [Seventh Modification] In the above embodiment or its modified example, a case where an interference optical system with a long coherence length is applied has been mainly described, but the configuration according to the embodiment is not limited thereto. The above embodiment or its modified example can be applied to an ophthalmic apparatus including an interference optical system with a short coherence length.

[0213] The seventh modified example of the embodiment will be described below, focusing on the differences from the embodiment. The difference between the configuration of the ophthalmic apparatus according to the seventh modified example of the embodiment and the configuration of the ophthalmic apparatus 1000 according to the embodiment is the configuration of the interference optical system included in the OCT unit 100.

[0214] Fig. 13 shows a configuration example of an interference optical system included in an OCT unit 100 according to a seventh modified example of the embodiment. In Fig. 13, the same parts as those in Fig. 2 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0215] In the interference optical system according to the seventh modification, a cornea reference optical path and a fundus reference optical path are provided with respect to the reference optical path in the interference optical system according to the embodiment. Specifically, a beam splitter 301 and reference mirrors 302 and 303 are provided in the optical path of the reference light LR converted into a parallel beam by the collimator 111. The reference light LR converted into a parallel beam by the collimator 111 is split by the beam splitter 301 and guided to the reference mirror 302 arranged in the cornea reference optical path and the reference mirror 303 arranged in the fundus reference optical path, respectively. The reference mirror 302 arranged in the cornea reference optical path is fixed in an optical position relative to the collimator 111 and the beam splitter 301 so that the optical path length of the reference light is a predetermined optical path length. The reference mirror 303 arranged in the fundus reference optical path is movable along the reference optical path. In some embodiments, it is moved along the reference optical path based on the operation content of the user on the operation unit 280. In some embodiments, the reference mirror 303 is moved along the reference optical path under control of the master controller 211 .

[0216] The reference light LR guided to the reference mirror 302 by the beam splitter 301 is reflected by the reference mirror 302, passes through the beam splitter 301, is converted from a parallel beam to a convergent beam by the collimator 116, and enters the optical fiber 117. The reference light LR guided to the reference mirror 303 by the beam splitter 301 is reflected by the reference mirror 303, is reflected by the beam splitter 301, is converted from a parallel beam to a convergent beam by the collimator 116, and enters the optical fiber 117. The rest is the same as in FIG. 2.

[0217] For example, when performing Z alignment using an OCT image near the cornea, the user or the main control unit 211 performs Z alignment of the device optical system with respect to the test eye E so that the cornea is positioned at a predetermined position in the OCT image formed based on the detection results of the interference light between the reference light that has passed through the cornea reference optical path and the return light of the measurement light from the test eye E.

[0218] For example, when performing Z alignment using an OCT image near the fundus, the user or the main controller 211 performs Z alignment of the device optical system with respect to the test eye E so that the cornea is located at a predetermined position in the OCT image formed based on the detection result of the interference light between the reference light passing through the reference optical path for the cornea and the return light of the measurement light from the test eye E. Thereafter, the user or the main controller 211 moves the reference mirror 303 to perform Z alignment of the device optical system with respect to the test eye E so that the fundus is located at a predetermined position in the OCT image formed based on the detection result of the interference light between the reference light passing through the reference optical path for the fundus and the return light of the measurement light from the test eye E.

[0219] In some embodiments, the reference mirror 303 is moved by a user's operation on the operation unit 280. In some embodiments, the main controller 211 moves the reference mirror 303 based on the interference intensity from the fundus obtained by the OCT provisional measurement.

[0220] In some embodiments, at least one of the optical path length compensation member 112 and the dispersion compensation member 113 is disposed in the reference optical path between the collimator 111 and the beam splitter 301. In some embodiments, at least one of the optical path length compensation member 112 and the dispersion compensation member 113 is disposed in the reference optical path between the beam splitter 301 and the collimator 116. In some embodiments, at least one of the optical path length compensation member 112 and the dispersion compensation member 113 is disposed in the reference optical path between the beam splitter 301 and the reference mirror 302, or between the beam splitter 301 and the reference mirror 303.

[0221] As described above, according to the seventh modification, even if the coherence length is short, highly accurate Z alignment for OCT measurement can be performed using an OCT image of the cornea and an OCT image of the fundus.

[0222] [Eighth Modification] In the seventh variant, the above embodiment or its variant is mainly described as being applied to an ophthalmic apparatus including an interference optical system with a long coherence length, but the configuration of the ophthalmic apparatus according to the embodiment is not limited to this.

[0223] The eighth modified example of the embodiment will be described below, focusing on the differences from the embodiment. The difference between the configuration of the ophthalmic apparatus according to the eighth modified example of the embodiment and the configuration of the ophthalmic apparatus 1000 according to the embodiment is the configuration of the interference optical system included in the OCT unit 100.

[0224] Fig. 14 shows a configuration example of an interference optical system included in an OCT unit 100 according to an eighth modified example of the embodiment. In Fig. 14, the same parts as those in Fig. 2 are given the same reference numerals, and the description will be omitted as appropriate.

[0225] In the interference optical system according to the eighth modification, as in the seventh modification, a reference optical path for the cornea and a reference optical path for the fundus are provided with respect to the reference optical path in the interference optical system according to the embodiment. The reference light LR branched by the fiber coupler 105 is guided to the fiber coupler 310 by the optical fiber 110. The fiber coupler 310 branches the reference light into the reference optical path for the cornea and the reference light into the reference optical path for the fundus at a predetermined branching ratio (for example, 1:1).

[0226] The corneal reference light path is provided with an optical fiber 311. That is, the reference light branched by the fiber coupler 310 is guided to the fiber coupler 320 by the optical fiber 311.

[0227] The fundus reference light path includes an optical fiber 312, a collimator 313, a reflecting mirror 314, an optical path length correction member 112, a dispersion compensation member 113, a corner cube 114, a reference mirror 315, a collimator 316, and an optical fiber 317. That is, the reference light branched by the fiber coupler 310 is guided to the collimator 313 by the optical fiber 312 and converted into a parallel beam by the collimator 313. The reference light converted into a parallel beam is reflected by the reflecting mirror 314 and, as in FIG. 2, is guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. As in FIG. 2, the corner cube 114 is movable in the incident direction of the reference light. 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 light beam to a convergent light beam by the collimator 316, and enters the optical fiber 317. The reference light that has entered the optical fiber 117 is guided to the fiber coupler 320.

[0228] The fiber coupler 320 combines the reference light guided by the optical fiber 311 and the reference light guided by the optical fiber 317. The reference light combined by the fiber coupler 320 is guided to the polarization controller 118 by the optical fiber 117. The rest of the configuration is the same as in FIG.

[0229] For example, when performing Z alignment using an OCT image near the cornea, the user or the main control unit 211 performs Z alignment of the device optical system with respect to the test eye E so that the cornea is positioned at a predetermined position in the OCT image formed based on the detection results of the interference light between the reference light that has passed through the cornea reference optical path and the return light of the measurement light from the test eye E.

[0230] For example, when Z-alignment is performed using an OCT image near the fundus, the user or the main controller 211 performs Z-alignment of the device optical system with respect to the subject's eye E so that the cornea is located at a predetermined position in the OCT image formed based on the detection result of the interference light between the reference light passing through the reference optical path for the cornea and the return light of the measurement light from the subject's eye E. Thereafter, the user or the main controller 211 moves the corner cube 114 to perform Z-alignment of the device optical system with respect to the subject's eye E so that the fundus is located at a predetermined position in the OCT image formed based on the detection result of the interference light between the reference light passing through the reference optical path for the fundus and the return light of the measurement light from the subject's eye E.

[0231] In some embodiments, the corner cube 114 is moved by a user's operation of the operation unit 280. In some embodiments, the main controller 211 moves the corner cube 114 based on the interference intensity from the fundus obtained by the OCT provisional measurement.

[0232] As described above, according to the eighth variant, like the seventh variant, it becomes possible to perform highly accurate Z alignment for OCT measurement using an OCT image of the cornea and an OCT image of the fundus, even when the coherence length is short.

[0233] [Actions and Effects] The operation and effects of the ophthalmic apparatus and the control method thereof according to the embodiment will be described.

[0234] An ophthalmic device (1000) according to some embodiments includes an objective lens (51), a refractive power measurement optical system (a refractive power measurement projection system 6, a refractive power measurement light receiving system 7), an OCT optical system (8), an image forming unit (220), a moving mechanism (200), an operation unit (270), and a control unit (210, a main control unit 211). The refractive power measurement optical system projects light onto the subject's eye (E) via the objective lens, and detects return light from the subject's eye. The OCT optical system has an optical scanner (88), splits light (L0) from a light source (OCT light source 101) into measurement light (LS) and reference light (LR), deflects the measurement light by the optical scanner, projects the measurement light deflected by the optical scanner onto the subject's eye via the objective lens, and detects interference light (LC) between the return light from the subject's eye and the reference light. The image forming unit forms an image of the subject's eye based on the detection result of the interference light. The moving mechanism moves the objective lens, the refractive power measuring optical system, and the OCT optical system relative to the subject's eye in the optical axis direction of the objective lens. The control unit controls the moving mechanism to set a predetermined working distance (WDref) with respect to the subject's eye when performing refractive power measurement (REF measurement) using the refractive power measuring optical system, and displays an image formed by the image forming unit on the display means (display unit 270) when performing OCT measurement using the OCT optical system, and controls the moving mechanism based on the operation content on the operation unit.

[0235] According to this configuration, the objective lens is shared at least in the refractive power measurement optical system and the OCT optical system, while the working distance is changed for the refractive power measurement and the OCT measurement, so that highly accurate refractive power measurement results and highly accurate OCT measurement results can be obtained with a simple configuration.

[0236] In an ophthalmologic apparatus according to some embodiments, an image forming unit forms a tomographic image of an area including an area corresponding to the cornea of ​​a subject's eye.

[0237] According to this configuration, alignment can be performed based on the position of the cornea, which is easily visible, so that highly accurate OCT measurement results can be easily obtained with a simple configuration.

[0238] An ophthalmic device (1000) according to some embodiments includes an objective lens (51), a refractive power measurement optical system (a refractive power measurement projection system 6, a refractive power measurement light receiving system 7), an OCT optical system (8), a determination unit (a data processing unit 223), a moving mechanism (200), and a control unit (210, a main control unit 211). The refractive power measurement optical system projects light onto the subject's eye (E) via the objective lens, and detects return light from the subject's eye. The OCT optical system has an optical scanner (88), splits light (L0) from a light source (OCT light source 101) into a measurement light (LS) and a reference light (LR), deflects the measurement light by the optical scanner, projects the measurement light deflected by the optical scanner onto the subject's eye via the objective lens, and detects interference light (LC) between the return light from the subject's eye and the reference light. The determination unit determines the position of a predetermined part of the subject's eye based on the detection result of the interference light. The moving mechanism moves the objective lens, the refractive power measuring optical system, and the OCT optical system relative to the subject's eye in the optical axis direction of the objective lens. The control unit controls the moving mechanism to set a predetermined working distance (WDref) with respect to the subject's eye when performing refractive power measurement (REF measurement) using the refractive power measuring optical system, and controls the moving mechanism based on the position of the predetermined site identified by the identification unit when performing OCT measurement using the OCT optical system.

[0239] According to this configuration, the objective lens is shared at least in the refractive power measurement optical system and the OCT optical system, while the working distance is changed for the refractive power measurement and the OCT measurement, so that highly accurate refractive power measurement results and highly accurate OCT measurement results can be obtained with a simple configuration.

[0240] In some embodiments of the ophthalmic device, the predetermined portion includes an area corresponding to the cornea.

[0241] According to this configuration, alignment can be performed based on the position of the cornea, which is easy to identify, so that highly accurate OCT measurement results can be easily obtained with a simple configuration.

[0242] An ophthalmic apparatus according to some embodiments includes an alignment optical system (Z alignment system 1) that irradiates alignment light onto the test eye from a direction different from the optical axis direction of the objective lens and detects the returned light, and a control unit controls a moving mechanism based on the detection results obtained by the alignment optical system when performing refractive power measurement.

[0243] According to this configuration, it is possible to obtain highly accurate refractive power measurement results with a simple configuration.

[0244] An ophthalmologic apparatus according to some embodiments includes an anterior-segment observation system (5) including a relay lens (56) that relays light from an anterior segment of an eye to be examined, and an image sensor (59) that receives the light that has passed through the relay lens. The control unit moves the relay lens to a first lens position on the optical axis of the anterior-segment observation system when performing refractive power measurement, and moves the relay lens to a second lens position on the optical axis of the anterior-segment observation system when performing OCT measurement.

[0245] With this configuration, even if the working distance is changed depending on the type of examination, including refractive power measurement and OCT measurement, it is possible to form an image of the signal from the anterior segment on the imaging surface of the imaging element, thereby making it possible to observe a focused image of the anterior segment in each examination.

[0246] An ophthalmologic apparatus according to some embodiments includes a fixation projection system (4) that projects a fixation target onto the subject's eye. A control unit controls the fixation projection system so that a first fixation target (FT1) is projected onto the subject's eye when performing refractive power measurement, and a second fixation target (FT2, FT3) having a narrower visual angle than the first fixation target is projected onto the subject's eye when performing OCT measurement.

[0247] According to this configuration, a fixation target with a different visual angle is presented to the test eye depending on the type of examination, including refractive power measurement and OCT measurement. Therefore, in refractive power measurement, a fixation target can be presented so as not to cause the test eye to adjust its vision, and in OCT measurement, a fixation target can be presented so as to position a desired portion of the test eye in a specified test position.

[0248] In some embodiments of the ophthalmic apparatus, the second fixation target is a dot target (FT2) or a cross target (FT3).

[0249] According to this configuration, it is possible to reliably cause the subject's eye to gaze at the second fixation target with a simple configuration.

[0250] A control method for an ophthalmic device (1000) according to some embodiments is a control method for an ophthalmic device including an objective lens (51), a refractive power measurement optical system (a refractive power measurement projection system 6, a refractive power measurement light receiving system 7), an OCT optical system (8), an image forming unit (220), a moving mechanism (200), an operation unit (270), and a control unit (210, a main control unit 211). The refractive power measurement optical system projects light onto a test eye (E) via an objective lens and detects return light from the test eye. The OCT optical system has an optical scanner (88), splits light (L0) from a light source (OCT light source 101) into a measurement light (LS) and a reference light (LR), deflects the measurement light by the optical scanner, projects the measurement light deflected by the optical scanner onto the test eye via the objective lens, and detects interference light (LC) between the return light from the test eye and the reference light. The moving mechanism moves the objective lens, the refractive power measuring optical system, and the OCT optical system relatively to the subject's eye in the optical axis direction of the objective lens. The control unit controls at least the moving mechanism. The control method for the ophthalmic device includes a first control step of controlling the moving mechanism to set a predetermined working distance (WDref) to the subject's eye, a first measurement step of controlling the refractive power measuring optical system to perform refractive power measurement after the working distance is changed in the first control step, an image formation step of forming an image of the subject's eye based on the detection result of the interference light, a second control step of displaying the image formed in the image formation step on a display means (display unit 270) and controlling the moving mechanism based on the operation content on the operation unit, and a second measurement step of controlling the OCT optical system to perform OCT measurement after the working distance is changed in the second control step.

[0251] According to this configuration, the objective lens is shared at least in the refractive power measurement optical system and the OCT optical system, while the working distance is changed for the refractive power measurement and the OCT measurement, so that highly accurate refractive power measurement results and highly accurate OCT measurement results can be obtained with a simple configuration.

[0252] A control method for an ophthalmic device (1000) according to some embodiments is a control method for an ophthalmic device including an objective lens (51), a refractive power measurement optical system (a refractive power measurement projection system 6, a refractive power measurement light receiving system 7), an OCT optical system (8), a determination unit (a data processing unit 223), a moving mechanism (200), and a control unit (210, a main control unit 211). The refractive power measurement optical system projects light onto a test eye (E) via an objective lens, and detects return light from the test eye. The OCT optical system has an optical scanner (88), splits light (L0) from a light source (OCT light source 101) into a measurement light (LS) and a reference light (LR), deflects the measurement light by the optical scanner, projects the measurement light deflected by the optical scanner onto the test eye via the objective lens, and detects interference light (LC) between the return light from the test eye and the reference light. The moving mechanism moves the objective lens, the refractive power measuring optical system, and the OCT optical system relatively in the optical axis direction of the objective lens with respect to the subject's eye. The control unit controls at least the moving mechanism. The control method for the ophthalmic device includes a first control step of controlling the moving mechanism to set a predetermined working distance (WDref) with respect to the subject's eye, a first measurement step of controlling the refractive power measuring optical system to perform refractive power measurement after the working distance is changed in the first control step, a specifying step of specifying a position of a predetermined site of the subject's eye based on a detection result of the interference light, a second control step of controlling the moving mechanism based on the position of the predetermined site specified in the specifying step, and a second measurement step of controlling the OCT optical system to perform OCT measurement after the working distance is changed in the second control step.

[0253] According to this configuration, the objective lens is shared at least in the refractive power measurement optical system and the OCT optical system, while the working distance is changed for the refractive power measurement and the OCT measurement, so that highly accurate refractive power measurement results and highly accurate OCT measurement results can be obtained with a simple configuration.

[0254] In a method for controlling an ophthalmic apparatus according to some embodiments, the ophthalmic apparatus includes an alignment optical system (Z alignment system 1) that irradiates an alignment light to an eye to be examined from a direction different from an optical axis direction of an objective lens and detects the return light. A first control step includes a step of controlling a moving mechanism based on a detection result obtained by the alignment optical system.

[0255] According to this configuration, it is possible to obtain highly accurate refractive power measurement results with a simple configuration.

[0256] In a method for controlling an ophthalmic apparatus according to some embodiments, the ophthalmic apparatus includes an anterior-segment observation system (5) including a relay lens (56) that relays light from an anterior segment of a subject's eye, and an image sensor (59) that receives light that has passed through the relay lens. The method for controlling the ophthalmic apparatus includes a first lens moving step of moving the relay lens to a first lens position on the optical axis of the anterior-segment observation system when performing refractive power measurement, and a second lens moving step of moving the relay lens to a second lens position on the optical axis of the anterior-segment observation system when performing OCT measurement.

[0257] With this configuration, even if the working distance is changed depending on the type of examination, including refractive power measurement and OCT measurement, it is possible to form an image of the signal from the anterior segment on the imaging surface of the imaging element, thereby making it possible to observe a focused image of the anterior segment in each examination.

[0258] In a control method for an ophthalmic apparatus according to some embodiments, the ophthalmic apparatus includes a fixation projection system (4) that projects a fixation target onto the subject's eye. The first measurement step includes a first projection step of controlling the fixation projection system to project a first fixation target onto the subject's eye. The second measurement step includes a second projection step of controlling the fixation projection system to project a second fixation target having a narrower visual angle than the first fixation target onto the subject's eye.

[0259] According to this configuration, a fixation target with a different visual angle is presented to the test eye depending on the type of examination, including refractive power measurement and OCT measurement. Therefore, in refractive power measurement, a fixation target can be presented so as not to cause the test eye to adjust its vision, and in OCT measurement, a fixation target can be presented so as to position a desired portion of the test eye in a specified test position.

[0260] <Other> The embodiment described above is merely one example for carrying out the present invention. Anyone who wishes to carry out the present invention may make any modifications, omissions, additions, etc. within the scope of the gist of the present invention.

[0261] In the above embodiment or its modified example, the ophthalmic apparatus performs OCT on the cornea (anterior segment) or the fundus Ef, but the configuration of the ophthalmic apparatus according to the embodiment is not limited to this. For example, the present invention can be applied to an ophthalmic apparatus that performs OCT on any part of the subject's eye.

[0262] In the above embodiment or its modified example, the ophthalmic apparatus performs Z alignment automatically or manually so that the position of the cornea or retina falls within a predetermined range, but the configuration of the ophthalmic apparatus according to the embodiment is not limited to this. For example, it is possible to perform Z alignment automatically or manually so that any part of the subject's eye falls within a predetermined range. [Explanation of symbols]

[0263] 1 Z alignment system 2 XY alignment system 3 Kerato measurement system 4 Fixation projection system 5 Anterior segment observation system 6 Reflector measurement projection system 7 Reflector measurement light receiving system 8 OCT optical system 9 Processing section 51 Objective Lens 88 Optical Scanner 200 Moving mechanism 210 Control section 211 Main control unit 1000 ophthalmology equipment

Claims

1. An objective lens; a refractive power measuring optical system that projects light onto the subject's eye through the objective lens and detects return light from the subject's eye; an OCT optical system having an optical scanner, dividing light from a light source into measurement light and reference light, deflecting the measurement light by the optical scanner, projecting the measurement light deflected by the optical scanner onto the subject's eye via the objective lens, and detecting interference light between return light from the subject's eye and the reference light; a moving mechanism that moves the objective lens, the refractive power measuring optical system, and the OCT optical system relatively to the subject's eye in a direction of an optical axis of the objective lens; a control unit that controls the moving mechanism so that a predetermined working distance is set with respect to the test eye when performing refractive power measurement using the refractive power measurement optical system, and controls the moving mechanism to move the OCT optical system in the optical axis direction of the objective lens so that a working distance corresponding to a scan range selected from a plurality of scan ranges is set when performing OCT measurement using the OCT optical system; a fixation projection system that projects a fixation target onto the subject's eye; Including, the fixation projection system includes an illumination light source, a transmissive optotype chart, and a plurality of fixation light sources disposed between the illumination light source and the optotype chart, and is configured to project a first fixation target onto the subject's eye by illuminating the optotype chart with light from the illumination light source, and to project a second fixation target, the size of which can be changed, onto the subject's eye by turning on a part or all of the plurality of fixation light sources, and to present the second fixation target on the first fixation target; The control unit controls the fixation projection system to project the first fixation target onto the test eye when performing the refractive power measurement, and to superimpose the second fixation target, which has a narrower visual angle than the first fixation target, onto the test eye when performing the OCT measurement.

2. an alignment optical system that irradiates alignment light onto the subject's eye from a direction different from an optical axis direction of the objective lens and detects return light; The control unit controls the moving mechanism based on a detection result obtained by the alignment optical system when performing the refractive power measurement.

2. An ophthalmic apparatus according to claim 1.

3. an anterior segment observation system including a relay lens that relays light from an anterior segment of the subject's eye, and an image pickup element that receives the light that has passed through the relay lens; The control unit moves the relay lens to a first lens position on the optical axis of the anterior eye observation system when performing the refractive power measurement, and moves the relay lens to a second lens position on the optical axis of the anterior eye observation system when performing the OCT measurement.

3. An ophthalmic apparatus according to claim 1 or 2.

4. The second fixation target is a dot target or a cross target. The ophthalmic apparatus according to any one of claims 1 to 3.

5. An objective lens; a refractive power measuring optical system that projects light onto the subject's eye through the objective lens and detects return light from the subject's eye; an OCT optical system having an optical scanner, dividing light from a light source into measurement light and reference light, deflecting the measurement light by the optical scanner, projecting the measurement light deflected by the optical scanner onto the subject's eye via the objective lens, and detecting interference light between return light from the subject's eye and the reference light; a moving mechanism that moves the objective lens, the refractive power measuring optical system, and the OCT optical system relatively to the subject's eye in a direction of an optical axis of the objective lens; a fixation projection system that projects a fixation target onto the subject's eye; A control unit; a control method for an ophthalmologic apparatus including: the fixation projection system including an illumination light source, a transmissive optotype chart, and a plurality of fixation light sources disposed between the illumination light source and the optotype chart; the control method being configured to project a first fixation target onto the subject's eye by illuminating the optotype chart with light from the illumination light source; and to project a second fixation target, the size of which can be changed, onto the subject's eye by turning on a part or all of the plurality of fixation light sources, and to present the second fixation target on the first fixation target, a first control step of controlling the moving mechanism so that the moving mechanism is at a predetermined working distance with respect to the subject's eye; a first measurement step of controlling the refractive power measurement optical system to perform a refractive power measurement after the working distance is changed in the first control step; a second control step of controlling the moving mechanism to move the OCT optical system in the optical axis direction of the objective lens so that the working distance corresponds to a scanning range selected from a plurality of scanning ranges; a second measurement step of controlling the OCT optical system to perform OCT measurement after the working distance is changed in the second control step; Including, the first measurement step includes a first projection step of controlling the fixation projection system to project a first fixation target onto the subject's eye, A method for controlling an ophthalmic apparatus, wherein the second measurement step includes a second projection step of controlling the fixation projection system to project a second fixation target having a narrower visual angle than the first fixation target onto the subject's eye by superimposing the first fixation target.

6. the ophthalmic apparatus includes an alignment optical system that irradiates alignment light onto the subject's eye from a direction different from an optical axis direction of the objective lens and detects return light; The first control step includes a step of controlling the moving mechanism based on a detection result obtained by the alignment optical system. The method for controlling an ophthalmic apparatus according to claim 5 .

7. the ophthalmologic apparatus includes an anterior-segment observation system including a relay lens that relays light from an anterior segment of the subject's eye, and an image sensor that receives the light that has passed through the relay lens; a first lens moving step of moving the relay lens to a first lens position on the optical axis of the anterior eye observation system when performing the refractive power measurement; a second lens moving step of moving the relay lens to a second lens position on the optical axis of the anterior eye observation system when performing the OCT measurement; Includes 7. The method for controlling an ophthalmic apparatus according to claim 5 or 6.

Images