Ophthalmologic apparatus, method for controlling ophthalmologic apparatus, program, and recording medium

Abstract

To improve the stability of a sight line during scanning of an anterior eye part using visible light.SOLUTION: An ophthalmologic apparatus 1 includes: a scanning unit 2; a fixation optical system 3; and a control unit 7. The scanning unit executes scanning of an anterior eye part of a subject eye E using visible light and collects images. The fixation optical system projects fixation light onto the subject eye. The control unit executes scan control that causes the scanning unit 2 to execute scanning and also executes fixation control that causes the fixation optical system 3 to modulate the fixation light in parallel with the scan control.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an ophthalmic device, a method for controlling the ophthalmic device, a program, and a recording medium.

Background Art

[0002] In the field of ophthalmology, image diagnosis plays an important role. In ophthalmic image diagnosis, various types of ophthalmic devices (ophthalmic imaging devices) such as a slit lamp microscope, a fundus camera, a scanning laser ophthalmoscope (SLO), and an optical coherence tomography (OCT) are used. The ophthalmic devices having an imaging function are not limited to these ophthalmic imaging devices, and imaging functions are also installed in ophthalmic examination devices and ophthalmic measurement devices such as a refractometer, a keratometer, a tonometer, a specular microscope, a wavefront analyzer, and a microperimeter.

[0003] Many ophthalmic devices have a fixation function for suppressing eye movement during imaging, examination, or preparation operations (alignment, focusing, etc.). For example, Patent Document 1 discloses an ophthalmic device that scans an eye to be examined using a shine-proof optical system, and is configured to scan the eye to be examined while projecting fixation light onto the eye to be examined along a projection optical axis different from the optical axis of the shine-proof optical system. The ophthalmic device of Patent Document 1 is particularly used for scanning the anterior segment of the eye.

[0004] In anterior segment scanning, illumination light including visible light is often used. On the other hand, visible light is also used for the fixation light that needs to be visually recognized by the subject. When scanning with visible illumination light and projecting fixation light are performed simultaneously, the fixation light may become invisible (or difficult to see) due to the visible illumination light, and the line of sight of the eye to be examined may become unstable. In particular, when the visible illumination light is projected onto the pupil, the subject feels strong glare, so that the visibility of the fixation light is extremely reduced.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One object of the present disclosure is to improve the stability of the line of sight during a anterior eye segment scan using visible light.

Means for Solving the Problems

[0007] One exemplary aspect of the embodiment is an ophthalmic device including a scan unit, a fixation optical system, and a control unit. The scan unit is configured to perform a scan of the anterior eye segment of the eye to be examined using visible light and collect an image. The fixation optical system is configured to project fixation light onto the eye to be examined. The control unit is configured to execute scan control for causing the scan unit to perform a scan of the anterior eye segment, and to execute fixation control for modulating the fixation light in the fixation optical system in parallel with the scan control.

[0008] Another exemplary aspect of the embodiment is a method for controlling an ophthalmic device for photographing the anterior eye segment of the eye to be examined. The ophthalmic device of this aspect includes a scan unit that performs a scan of the anterior eye segment using visible light and collects an image, a fixation optical system that projects fixation light onto the eye to be examined, and a processor. The method of this aspect causes the processor of the ophthalmic device to execute scan control for causing the scan unit to perform a scan of the anterior eye segment, and to execute fixation control for modulating the fixation light in the fixation optical system in parallel with the scan control.

[0009] Yet another exemplary aspect of the embodiment is a program for causing a computer to execute the method according to the exemplary aspect.

[0010] Still another exemplary aspect of the embodiment is a computer-readable non-transitory recording medium on which the program according to the exemplary aspect is recorded.

Advantages of the Invention

[0011] According to an embodiment, it is possible to improve the stability of the line of sight during a front-eye scan using visible light.

Brief Description of the Drawings

[0012]

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Modes for Carrying Out the Invention

[0013] Non-limiting embodiments according to the present disclosure will be described.

[0014] Any known technology can be combined with the embodiments. For example, any matter described in the documents cited in the present disclosure can be combined with any aspect of the embodiments. Further, at least one of any known document related to the technical field of the present disclosure, any known technology in a technical field similar to the technical field of the present disclosure, and any known technology in a technical field different from the technical field of the present disclosure can be combined with any aspect of the embodiments.

[0015] For example, the matters disclosed in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-49320) can be incorporated into the present disclosure by reference. More generally, any technical matter (matters disclosed in patent applications, papers, etc.) disclosed by the applicant of the present application regarding the technology related to the present disclosure can be incorporated into the present disclosure by reference.

[0016] Any two or more of the various non-limiting aspects according to the embodiments can be at least partially combined.

[0017] At least some of the functions of any aspect described in this disclosure are implemented using circuitry or processing circuitry. The circuitry or processing circuitry includes a general-purpose processor, a dedicated processor, an integrated circuit, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (e.g., SPLD (Simple Programmable Logic Device), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array), conventional circuitry, and any combination thereof, configured and / or programmed to perform at least some of the disclosed functions. A processor is considered to be a processing circuitry or circuitry that includes transistors and / or other circuitry. In this disclosure, terms such as circuitry, unit, means, or the like refer to hardware that performs at least some of the disclosed functions, or hardware programmed to perform at least some of the disclosed functions. The hardware may be the hardware disclosed herein, or it may be known hardware programmed and / or configured to perform at least some of the described functions. When the hardware is a processor that can be considered a type of circuitry, the terms circuitry, unit, means, or the like refer to a combination of hardware and software, and this software is used to configure the hardware and / or the processor.

[0018] <Summary of Embodiments> One object of the embodiments according to the present disclosure is to improve the stability of the line of sight of the eye to be examined while applying a scan using visible light to the anterior segment of the eye. More specifically, in the embodiments according to the present disclosure, when performing a scan with visible illumination light and projecting fixation light simultaneously, by improving or eliminating a decrease in the visibility of the fixation light that occurs when the pupil is being scanned, etc., it is possible to achieve the effect of improving the stability of the line of sight.

[0019] Note that the effects of the embodiments according to the present disclosure are not limited to improving the stability of the line of sight during anterior segment scanning. Some non-limiting aspects of the embodiments will be described below, but those skilled in the art will be able to understand that each aspect exhibits effects corresponding to its features (configuration, operation, action, use, etc.).

[0020] A first aspect of the embodiment is an ophthalmic device configured to modulate visible illumination light during anterior segment scanning. More specifically, the ophthalmic device of this aspect includes a scan unit, a fixation optical system, and a control unit. The scan unit is configured to perform a scan of the anterior segment of the eye to be examined using visible light and collect an image. The fixation optical system is configured to project fixation light onto the eye to be examined. The control unit is configured to execute control of the ophthalmic device. In particular, the control unit is configured to execute scan control for causing the scan unit to perform an anterior segment scan, and to execute fixation control for modulating the fixation light in the fixation optical system in parallel with the scan control.

[0021] The ophthalmic device according to the first aspect can perform an anterior segment scan with visible illumination light and project fixation light onto the eye to be examined simultaneously, and at that time, can modulate the fixation light while performing the anterior segment scan. By modulating the fixation light, it is possible to change the visibility state of the fixation light by the subject. Therefore, in this aspect, it is possible to utilize the modulation of the fixation light to improve or eliminate a decrease in the visibility of the fixation light during anterior segment scanning. Thus, according to this aspect, it is possible to improve the stability of the line of sight during anterior segment scanning using visible light.

[0022] The parameter (optical property) modulated by the ophthalmic device according to the first aspect may be any parameter that can change the visual recognition state of the fixation light by the subject, and may be arbitrarily selected from various types of parameters. Also, the type of parameter to be modulated may be one or two or more.

[0023] The second aspect of the embodiment is the ophthalmic device of the first aspect, wherein the control unit is configured to change the light amount of the fixation light in fixation control. That is, the parameter of the fixation light modulated by the ophthalmic device of this aspect includes at least "light amount". As described above, the parameter of the fixation target modulated in this aspect may be only the light amount, or may include the light amount and another parameter.

[0024] The ophthalmic device according to the second aspect can change the visual recognition state of the fixation light by the subject by modulating the light amount of the fixation light during the anterior eye segment scan. Therefore, this aspect can utilize the modulation of the intensity of the fixation light to improve or eliminate the decrease in the visibility of the fixation light during the anterior eye segment scan. Thus, according to this aspect, it is possible to improve the stability of the line of sight during the anterior eye segment scan using visible light.

[0025] The third aspect of the embodiment is the ophthalmic device of the second aspect, wherein the control unit executes scan control for causing the scan unit to perform an anterior eye segment scan in the following manner, and executes fixation control for modulating the fixation light in the fixation optical system in the following manner.

[0026] In the scan control, the control unit causes the scan unit to perform a scan of a non-pupil region that does not include the pupil of the anterior eye segment of the eye to be examined and a scan of a pupil region that includes the pupil. That is, the target range of the anterior eye segment scan of this aspect is the range of the anterior eye segment that includes both a part or the whole of the anterior eye segment region corresponding to the part other than the pupil and a part or the whole of the region corresponding to the pupil.

[0027] Also, in fixation control, during the execution of the scan of the non-pupil region among the anterior eye segment scans executed by scan control, the control unit generates fixation light having a first light quantity in the fixation optical system, and during the execution of the scan of the pupil region, generates fixation light having a second light quantity greater than the first light quantity in the fixation optical system.

[0028] According to the ophthalmic apparatus according to the third aspect, the light quantity of the fixation light when scanning the pupil can be made larger than the light quantity of the fixation light when scanning a site other than the pupil.

[0029] When the visible light for the anterior eye segment scan is not projected onto the pupil, since the visible light is blocked by the iris and does not reach the retina, the subject does not feel strong glare. On the other hand, when the visible light is projected onto the pupil, since the visible light passes through the pupil and reaches the retina, the subject feels strong glare. Therefore, the visibility of the fixation light is relatively high when the visible light is not projected onto the pupil, and the visibility of the fixation light is relatively low when the visible light is projected onto the pupil. This aspect can enhance the visibility of the fixation light by increasing the light quantity of the fixation light when the visible light is projected onto the pupil.

[0030] It is also conceivable to project fixation light with a large light quantity onto the eye to be examined even when the visible light is not projected onto the pupil. However, if this is done, the subject has to continuously visually recognize the fixation light with a large light quantity even when the visibility of the fixation light is good, which increases the burden on the subject. Also, pupillary constriction (miosis) will occur. Therefore, as in this aspect, it can be said that it is desirable to switch the light quantity of the fixation light between the scan of the non-pupil region and the scan of the pupil region, more specifically, to use fixation light with a relatively small light quantity during the scan of the non-pupil region and use fixation light with a relatively large light quantity during the scan of the pupil region.

[0031] A fourth aspect of the embodiment is an ophthalmic apparatus according to the third aspect, which is configured to execute the following control when performing an anterior eye segment scan from the inner canthus side toward the outer canthus side or when performing an anterior eye segment scan from the outer canthus side toward the inner canthus side.

[0032] In the field of ophthalmology, the inner canthus side is often referred to as the nasal side, and the outer canthus side is often referred to as the temporal side. In this aspect, one of the temporal side and the nasal side is referred to as the "first side", and the other is referred to as the "second side". In this aspect, the anterior eye segment of the eye to be examined is scanned from the first side toward the second side.

[0033] In the scan control for causing the scan unit to execute an anterior eye segment scan, the control unit of the fourth aspect causes the scan unit to execute, as a series of scans, the scan of the first non-pupil region located on the first side, the scan of the pupil region, and the scan of the second non-pupil region located on the second side. That is, the anterior eye segment scan of this aspect executes the scan of the first non-pupil region, the scan of the pupil region, and the scan of the second non-pupil region in this order.

[0034] Also, in the fixation control for modulating the fixation light in the fixation optical system, the control unit of this aspect switches the light amount of the fixation light from the first light amount to the second light amount in correspondence with the transition from the scan of the first non-pupil region to the scan of the pupil region. Further, the control unit of this aspect switches the light amount of the fixation light from the second light amount to the first light amount in correspondence with the transition from the scan of the pupil region to the scan of the second non-pupil region.

[0035] Thus, the control unit of this aspect, in parallel with the scan control for the anterior eye segment scan executed in the order of the scan of the first non-pupil region, the scan of the pupil region, and the scan of the second non-pupil region, increases the light amount of the fixation light corresponding to the switch from the scan of the first non-pupil region to the scan of the pupil region (switch from the first light amount to the second light amount) and decreases the light amount of the fixation light corresponding to the switch from the scan of the pupil region to the scan of the second non-pupil region (switch from the second light amount to the first light amount).

[0036] According to the ophthalmic apparatus according to the fourth aspect, when performing an anterior eye segment scan from the inner canthus side toward the outer canthus side, or when performing an anterior eye segment scan from the outer canthus side toward the inner canthus side, the visibility of the fixation light can be enhanced by increasing the amount of the fixation light when visible light is projected onto the pupil.

[0037] In the fourth aspect, the amount of the fixation light is switched from the second light amount to the first light amount in response to the switching from the scan of the pupil region to the scan of the second non-pupil region, but the embodiment is not limited thereto. For example, considering the influence of the afterimage (positive afterimage) of the visible illumination light when scanning the pupil region and the influence of miosis, it may not be necessary to switch the amount of the fixation light corresponding to the switching from the scan of the pupil region to the scan of the second non-pupil region. Alternatively, in response to the switching from the scan of the pupil region to the scan of the second non-pupil region, the amount of the fixation light may be switched from the second light amount to the third light amount. The third light amount may be, for example, a light amount greater than the first light amount and smaller than the second light amount, or a light amount greater than the second light amount.

[0038] The fifth aspect of the embodiment is an ophthalmic apparatus according to any one of the first to fourth aspects, wherein the control unit is configured to change any one of the wavelength of the fixation light (the color of the fixation light, the color of the fixation target), the intensity modulation frequency of the fixation light, the emission size of the fixation light (the size of the fixation target), and the emission shape of the fixation light (the shape of the fixation target) in the fixation control for modulating the fixation light in the fixation optical system.

[0039] This aspect provides some examples of the parameters of the fixation light modulated by the ophthalmic apparatus according to the first aspect, and provides an example different from the example (light amount) of the second aspect.

[0040] The ophthalmic apparatus according to the fifth aspect can change the visual recognition state of the fixation light by the subject by modulating one or more parameters among the wavelength, intensity modulation frequency, emission size, and emission shape of the fixation light during the anterior eye segment scan. Therefore, in this aspect, in order to improve or eliminate the decrease in the visibility of the fixation light during the anterior eye segment scan, it is possible to utilize the modulation of any of the wavelength, intensity modulation frequency, emission size, and emission shape of the fixation light. Thus, according to this aspect, it is possible to improve the stability of the line of sight during the anterior eye segment scan using visible light.

[0041] The sixth aspect of the embodiment is a generalization of the third aspect. This aspect is an ophthalmic apparatus according to any one of the first to fifth aspects, and the control unit is configured to execute scan control for causing the scan unit to perform an anterior eye segment scan in the following manner, and to execute fixation control for modulating the fixation light in the fixation optical system in the following manner.

[0042] In the scan control, the control unit causes the scan unit to perform a scan of a non-pupil region that does not include the pupil of the anterior eye segment of the eye to be examined and a scan of a pupil region that includes the pupil. The scan control in this example is the same as the scan control in the second aspect.

[0043] Also, in the fixation control, the control unit causes the fixation optical system to generate fixation light having mutually different characteristics during the execution of the scan of the non-pupil region and during the execution of the scan of the pupil region. In other words, the control unit in this example causes the fixation optical system to generate fixation light having a first characteristic during the execution of the scan of the non-pupil region in the fixation control, and causes the fixation optical system to generate fixation light having a second characteristic different from the first characteristic during the execution of the scan of the pupil region. The fixation control in this example is a generalization of the fixation control in the second aspect.

[0044] According to the ophthalmic apparatus according to the sixth aspect, it is possible to apply fixation light having characteristics different from those of the fixation light applied to the eye to be examined during the execution of the scan of the non-pupil region during the execution of the scan of the pupil region so as to enhance the visibility of the fixation light.

[0045] The seventh aspect of the embodiment is the ophthalmic apparatus of the sixth aspect, further including a scan range determination unit. The scan range determination unit is configured to determine a scan range of the non-pupil region and a scan range of the pupil region.

[0046] It can be said that the scan range determination unit is configured to determine the range of the scan applied to the anterior eye part by scan control and to determine the switching timing of the characteristics of the fixation light in fixation control.

[0047] In the region of the anterior eye part, since the pupil region and the non-pupil region are in a complementary set relationship with each other, determining both the scan range of the non-pupil region and the scan range of the pupil region is synonymous with determining the scan range of the non-pupil region, and is also synonymous with determining the scan range of the pupil region.

[0048] Also, determining the scan range of the non-pupil region and / or the scan range of the pupil region is synonymous with determining the boundary between the non-pupil region and the pupil region, and is also synonymous with determining the boundary between the scan range of the non-pupil region and the scan range of the pupil region.

[0049] The range of the scan can be expressed by any parameter that defines it. Examples of such parameters are as follows: the position of the scan optical system provided in the scan unit (for example, the position parameter detected by a position detector such as an encoder); the control state of the scan mechanism that moves the scan optical system (for example, the control information provided to the actuator of the scan mechanism in scan control (such as the number of control pulses)); the operating state of the scan mechanism (for example, the rotational position of the motor or gear of the scan mechanism).

[0050] In this aspect, at least a part of the determination of the scan range can be automatically determined. Also, the automatically determined scan range may be manually changed, or the manually determined scan range may be automatically changed.

[0051] When the ophthalmic device according to the seventh aspect executes an anterior segment scan including a scan of the non-pupil region and a scan of the pupil region, it is possible to determine the scan range of the non-pupil region and the scan range of the pupil region. Therefore, according to this aspect, it is possible to determine the scan range according to each individual eye to be examined. Further, according to this aspect, it is also possible to determine the scan range according to the state of the eye to be examined (such as pupil diameter, disease, etc.).

[0052] The eighth aspect of the embodiment provides an example of the scan range determination unit of the seventh aspect. This aspect is an ophthalmic device according to the seventh aspect, and the scan range determination unit is configured to determine the scan range of the non-pupil region and the scan range of the pupil region based on the pupil size of the eye to be examined.

[0053] The pupil size may be any parameter indicating the size of the pupil of the eye to be examined. For example, the value of the pupil size may be any of the following values: the value of the diameter, radius, circumference, or area obtained by approximating the contour (outer peripheral edge) of the pupil as a circle; the value of the major axis, minor axis, average diameter, circumference, or area obtained by approximating the contour of the pupil as an ellipse; the value of the length of the contour of the pupil, the maximum diameter value, the minimum diameter value, the average diameter value; the value of the area of the pupil. The measurement of the pupil size may be performed as a preparation step for the examination (anterior segment scan) of the eye to be examined, or may be performed in advance.

[0054] According to the ophthalmic device according to the eighth aspect, it is possible to determine a suitable scan range according to the state (pupil size) of each individual eye to be examined.

[0055] The ninth aspect of the embodiment provides an example of the scan range determination unit of the eighth aspect. This aspect is an ophthalmic device according to the eighth aspect, and the scan range determination unit is configured to determine the scan range of the non-pupil region and the scan range of the pupil region based on the pupil size of the eye to be examined and the start position and end position of the scan applied to the anterior segment of the eye to be examined by the scan unit.

[0056] The start position and end position of the scan may be set in advance or may be set based on the eye to be examined. The start position and end position of the scan may include any of the following information set before the examination or in the examination preparation process: the length of the scan (the moving distance of the visible illumination light, the distance between the start position and the end position); a position set based on a predetermined part of the eye or its periphery (for example, a position at a predetermined distance away from the pupil toward the ear side and / or the nose side, or a position at a predetermined distance away from the inner or outer corner of the eye in the direction of the pupil).

[0057] In some examples, the center of the scan (the midpoint of the line segment connecting the start position and the end position) may be arranged at a predetermined feature point of the anterior segment of the eye (for example, the pupil center, the corneal apex, etc.). In that case, the start position and end position of the scan are synonymous with the length of the scan.

[0058] According to the ophthalmic apparatus according to the ninth aspect, it is possible to determine a more suitable scan range according to the state (pupil size) of each eye to be examined and the scan conditions.

[0059] The tenth aspect of the embodiment provides an example for assisting the scan range determination of the eighth aspect. This aspect is an ophthalmic apparatus according to the eighth or ninth aspect, and further includes an observation system. The observation system is configured to capture a moving image of the anterior segment of the eye to be examined and generate an observation image. The observation image is a time-series image (moving image). The scan range determination unit of this aspect is configured to obtain the pupil size of the eye to be examined by analyzing the observation image generated by the observation system. The scan range determination unit of this aspect determines the scan range of the non-pupil region and the scan range of the pupil region based on this pupil size (as well as the start position and end position of the scan).

[0060] The content of the process executed to obtain the pupil size from the observation image may be arbitrary. The process includes, for example, a process of applying segmentation to a frame of the observation image (anterior segment image) to detect an image region corresponding to the pupil, and a process of obtaining the size of this image region (described above).

[0061] According to the ophthalmic device according to the tenth aspect, it is possible to grasp the state (pupil size) of the eye to be examined from an image and determine a suitable scan range according to the eye to be examined.

[0062] The eleventh aspect of the embodiment provides an example of the tenth aspect, and obtains the pupil size from the observation image used for alignment (alignment) of the scanning unit with respect to the eye to be examined or the observation image obtained after the alignment. The observation image obtained after the alignment may be, for example, the observation image used for the preparatory operation (for example, focusing) executed after the alignment, or the image used for the operation (tracking) of causing the scanning unit to follow the movement of the eye to be examined.

[0063] This aspect is an ophthalmic device according to the tenth aspect, and the scanning unit includes an illumination system and an imaging system. The illumination system is configured to project visible light (visible illumination light) onto the anterior eye of the eye to be examined. The imaging system is configured to image the anterior eye onto which the visible illumination light is projected.

[0064] Further, the ophthalmic device of this aspect further includes a moving mechanism and an alignment unit. The moving mechanism is configured to move the illumination system and the imaging system. The moving mechanism may be configured to move the entire scanning unit, or may be configured to move only a part of the scanning unit (including the illumination system and the imaging system). In the latter case, the moving mechanism may be arranged or designed as an element of the scanning unit, or may be arranged or designed as an element separate from the scanning unit.

[0065] The alignment unit performs processes for aligning the illumination system and the imaging system with respect to the eye to be examined. Specifically, the alignment unit executes a process of analyzing an observation image generated by the observation system to determine the relative positions of the illumination system and the imaging system with respect to the eye to be examined, and a process of controlling the movement mechanism based on this relative position. Various alignment methods are known. At least a part of the processes executed by the alignment unit may be known methods. Typically, the alignment unit detects feature points (e.g., the pupil center) of the anterior eye segment, and adjusts the positions of the illumination system and the imaging system using this feature point as a reference or target.

[0066] In this aspect, an observation image generated by the observation system during or after the execution of alignment is provided to the scan range determination unit. The scan range determination unit of this aspect analyzes an observation image generated by the observation system during or after the execution of alignment to obtain the pupil size of the eye to be examined, and determines the scan range of the non-pupil region and the scan range of the pupil region based on this pupil size (as well as the start position and end position of the scan).

[0067] The ophthalmic apparatus according to the eleventh aspect can calculate (estimate, measure) the pupil size and determine the scan range using the observation image used in the operation performed before the anterior eye segment scan. Therefore, in this aspect, it is not necessary to provide a dedicated observation system for calculating the pupil size. Thus, according to this aspect, it is possible to determine a suitable scan range according to the eye to be examined while simplifying the device configuration.

[0068] Furthermore, in this aspect, the observation image used in the operation (e.g., alignment, focusing, tracking) performed before the anterior eye segment scan can be directly used for calculating the pupil size. Therefore, in this aspect, it is not necessary to perform imaging (acquisition of an observation image) only for the purpose of calculating the pupil size. Thus, according to this aspect, in addition to simplifying the device configuration, it is possible to simplify the inspection process of the eye to be examined and shorten the time, while determining a suitable scan range according to the eye to be examined.

[0069] The twelfth aspect of the embodiment provides an example of the configuration of the optical system of the ophthalmic device. More specifically, this aspect provides an example of the positional relationship between the scanning unit and the fixation optical system.

[0070] This aspect is an ophthalmic device according to any one of the first to eleventh aspects, wherein the scanning unit includes an illumination system and an imaging system. The illumination system is configured to project visible light (visible illumination light) onto the anterior eye part of the eye to be examined. The imaging system is configured to image the anterior eye part onto which the visible illumination light is projected.

[0071] Also, the fixation optical system of this aspect is configured to project fixation light onto the eye to be examined from a direction different from both the projection direction of the visible light onto the anterior eye part by the illumination system and the imaging direction of the anterior eye part by the imaging system. In other words, in this aspect, the optical axis of the fixation optical system is arranged in a direction different from the direction of the optical axis of the illumination system and the direction of the optical axis of the imaging system.

[0072] The positional relationship between the scanning unit and the fixation optical system is not limited to that of this aspect. For example, as in another aspect described later, the fixation optical system may be configured to project fixation light onto the eye to be examined from a direction the same as either the projection direction of the visible light onto the anterior eye part by the illumination system or the imaging direction of the anterior eye part by the imaging system. In other words, in the other aspect, the optical axis of the fixation optical system may be arranged in a direction the same as at least one of the direction of the optical axis of the illumination system and the direction of the optical axis of the imaging system.

[0073] The thirteenth aspect of the embodiment provides an example of a scanning method executable by the ophthalmic device. This aspect is the ophthalmic device of the twelfth aspect, wherein the illumination system and the imaging system of the scanning unit are configured as a shine-proof optical system that satisfies the shine-proof conditions. Further, the scanning unit of this aspect further includes a scanning mechanism. The scanning mechanism is configured to integrally move the illumination system and the imaging system without moving the fixation optical system.

[0074] The anti-shineproof condition is a condition related to an optical system (lighting system) that projects illumination light onto an object and an optical system (imaging system) that captures the object, and defines that the illumination system and the imaging system are configured such that the object plane, the lens principal plane, and the film plane (imaging plane) intersect on the same straight line. Since the object plane is not arranged parallel to the lens principal plane in the optical system that satisfies the anti-shineproof condition, according to a camera (anti-shineproof camera) using this optical system, it is possible to perform imaging while focusing simultaneously over a wide depth range from a nearby object to a distant object.

[0075] In the anterior eye imaging of this embodiment, for example, it is possible to perform imaging while focusing over a wide depth range from the anterior surface of the cornea to the posterior surface of the lens. Therefore, according to this embodiment, it is possible to express the entire main observation target of the anterior eye with high definition in a state where the line of sight of the eye to be examined is stabilized.

[0076] In the present disclosure, a mechanism that moves the illumination system and the imaging system for anterior eye scanning may be referred to as a scanning mechanism, and a mechanism that moves the illumination system and the imaging system for alignment may be referred to as a moving mechanism. The scanning mechanism is configured to move the illumination system and the imaging system while the fixation optical system does not move. On the other hand, the moving mechanism may be configured to move the illumination system and the imaging system while the fixation optical system does not move, or may be configured to move the fixation optical system in addition to the illumination system and the imaging system. Both the scanning mechanism and the moving mechanism are for moving the illumination system and the imaging system. At least a part of the scanning mechanism and at least a part of the moving mechanism may be common elements, or the scanning mechanism and the moving mechanism may be completely separate elements.

[0077] In one example, the scanning unit and the fixation optical system are mounted on the same unit. Further, the moving mechanism for alignment is disposed outside of this unit and is configured to move the entire unit. Furthermore, the scanning mechanism for anterior eye segment scanning is disposed inside the unit, and the fixation optical system is configured to move the illumination system and the imaging system without moving itself. In this example, the moving mechanism and the scanning mechanism are separate elements from each other.

[0078] In another example, the moving mechanism and the scanning mechanism are the same element (referred to as a moving part). The moving part moves the unit on which the scanning unit is mounted. In this example, the fixation optical system is disposed at a location other than this unit, and is disposed or connected, for example, to another unit, a base part (base), or an element for holding the subject's face (forehead rest, chin rest, members supporting them, etc.).

[0079] The 14th aspect of the embodiment provides another example different from the 12th aspect regarding the configuration of the optical system of the ophthalmic apparatus. More specifically, this aspect provides another example different from the 12th aspect regarding the positional relationship between the scanning unit and the fixation optical system.

[0080] This aspect is an ophthalmic apparatus according to any one of the 1st to 11th aspects, wherein the scanning unit includes an illumination system and an imaging system. The illumination system is configured to project visible light (visible illumination light) onto the anterior eye segment of the eye to be examined. The imaging system is configured to image the anterior eye segment onto which the visible illumination light has been projected.

[0081] Further, the ophthalmic apparatus of this aspect further includes an optical path coupling element. The optical path coupling element is configured to couple the optical path of the fixation optical system to the optical path of the illumination system or the optical path of the imaging system. The type of optical element that can be used as the optical path coupling element may be determined, for example, based on the relationship between the wavelength of the visible illumination light and the wavelength of the fixation light, and may be a half mirror or a dichroic mirror. Also, when considering the relationship between the polarization characteristics of the visible illumination light and the polarization characteristics of the fixation light, a polarization beam splitter may be used as the optical path coupling element.

[0082] The 15th aspect of the embodiment provides an example different from the 13th aspect regarding the scanning method executable by the ophthalmic device. This aspect is the ophthalmic device of the 14th aspect, wherein the illumination system and the imaging system of the scanning unit are configured as a shine-proof optical system that satisfies the shine-proof conditions. Further, the scanning unit of this aspect further includes a scanning mechanism. The scanning mechanism is configured to integrally move the illumination system and the imaging system without moving the fixation optical system.

[0083] Furthermore, in this aspect, the dimension of the optical path coupling element in the moving direction of the illumination system and the imaging system by the scanning mechanism is designed to be larger than the moving distance of the illumination system and the imaging system. That is, in this aspect, the anterior eye segment scan is performed by moving the illumination system and the imaging system by a predetermined moving distance in a predetermined moving direction by the scanning mechanism. And the dimension of the optical path coupling element in the moving direction is designed to be larger than the moving distance. Thereby, even if the illumination system and the imaging system are moved for the anterior eye segment scan, the fixation light can be projected onto the eye to be examined from the same direction via the optical path coupling element.

[0084] According to this aspect, it is possible to highly precisely represent the entire main observation target of the anterior eye segment in a state where the line of sight of the eye to be examined is stabilized.

[0085] The 16th aspect of the embodiment is capable of executing an operation (tracking) of causing the scanning unit to follow the movement of the eye to be examined. This aspect is the ophthalmic device of any one of the 1st to 15th aspects, wherein the scanning unit includes an illumination system and an imaging system. The illumination system is configured to project visible light (visible illumination light) onto the anterior eye segment of the eye to be examined. The imaging system is configured to image the anterior eye segment onto which the visible light is projected.

[0086] The ophthalmic apparatus of this aspect further includes a moving mechanism that moves the illumination system and the imaging system. Typically, the moving mechanism of this aspect is the same element as the moving mechanism for the alignment described above, and may be an element disposed inside or outside the scanning unit according to the arrangement relationship between the illumination system, the imaging system, and the fixation optical system.

[0087] The ophthalmic apparatus of this aspect further includes an observation system and an image analysis unit. The observation system is configured to capture a moving image of the anterior segment of the eye to be examined and generate an observation image. Typically, the observation system of this aspect is the same element as the observation system for the alignment described above. The image analysis unit is configured to obtain the time-series change of the relative position of the illumination system and the imaging system with respect to the eye to be examined by analyzing the observation image generated by the observation system. Thus, the ophthalmic apparatus of this aspect can monitor the change in the relative position between the eye to be examined and the illumination system and the imaging system by combining the observation system and the image analysis unit.

[0088] The control unit of this aspect is configured to execute the scanning control for causing the scanning unit to perform an anterior segment scan and the fixation control for modulating the fixation light on the fixation optical system in parallel, and further execute the tracking control in parallel. The tracking control sequentially controls the moving mechanism based on the time-series change of the relative position of the illumination system and the imaging system with respect to the eye to be examined obtained by the image analysis unit. In this tracking control, the illumination system and the imaging system are moved so as to cancel the relative position. Thereby, the illumination system and the imaging system can be made to follow the movement of the eye to be examined.

[0089] According to the ophthalmic apparatus according to the 16th aspect, it is possible to perform an anterior segment scan and modulation of the fixation light while automatically and real-time adjusting the positions of the illumination system and the imaging system in accordance with the movement of the eye to be examined. Therefore, even when the eye to be examined is displaced during the execution of the anterior segment scan, it is possible to collect a suitable image group by the anterior segment scan.

[0090] Any two or more matters related to the first to the sixteenth aspects can be at least partially combined. Also, any matter described in the present disclosure can be at least partially combined with the first to the sixteenth aspects. The ophthalmic device of the aspect obtained by such combination exhibits the operational effects based on each combined matter and also exhibits the synergistic operational effects of two or more combined matters.

[0091] The seventeenth aspect of the embodiment provides an invention of a method corresponding to the ophthalmic device of the first aspect. The method of this aspect is a method for controlling an ophthalmic device for photographing the anterior segment of an eye to be examined. The ophthalmic device controlled by the method of this aspect includes a scan unit, a fixation optical system, and a processor. The scan unit executes a scan of the anterior segment of the eye to be examined using visible light and collects an image. The fixation optical system projects fixation light onto the eye to be examined. The method of this aspect causes the processor to execute scan control and, in parallel with this scan control, execute fixation control. In the scan control, the processor causes the scan unit to execute a scan. In the fixation control, the processor causes the fixation optical system to modulate the fixation light.

[0092] According to the method according to the seventeenth aspect, the ophthalmic device can simultaneously perform a scan of the anterior segment with visible illumination light and projection of fixation light onto the eye to be examined, and at that time, it is possible to change the visual recognition state of the fixation light by the subject by modulating the fixation light while performing the scan of the anterior segment. Therefore, in this aspect, modulation of the fixation light can be used to improve or eliminate the decrease in visibility of the fixation light during the scan of the anterior segment. Thus, according to this aspect, it is possible to improve the stability of the line of sight during the scan of the anterior segment using visible light.

[0093] Any matter regarding the 1st to 16th aspects can be at least partially combined with the 17th aspect. Also, any matter described in this disclosure can be at least partially combined with the 17th aspect. The method of the aspect obtained by such combination exhibits the effects based on each combined matter and also exhibits the synergistic effects of two or more combined matters.

[0094] The 18th aspect of the embodiment is a program for causing a computer to execute the method of the 17th aspect. The computer of the 18th aspect includes the processor of the 17th aspect.

[0095] According to the program according to the 18th aspect, similar to the method of the 17th aspect, it becomes possible to improve the stability of the line of sight during the anterior eye segment scan using visible light.

[0096] Any matter regarding the 1st to 16th aspects can be at least partially combined with the 18th aspect. Also, any matter described in this disclosure can be at least partially combined with the 18th aspect. The program of the aspect obtained by such combination exhibits the effects based on each combined matter and also exhibits the synergistic effects of two or more combined matters.

[0097] The 19th aspect of the embodiment is a computer-readable non-transitory recording medium on which the program of the 18th aspect is recorded.

[0098] According to the recording medium according to the 19th aspect, similar to the program of the 18th aspect, it becomes possible to improve the stability of the line of sight during the anterior eye segment scan using visible light.

[0099] Any matter regarding Aspects 1 to 16 can be at least partially combined with Aspect 19. Also, any matter described in the present disclosure can be at least partially combined with Aspect 19. The recording medium of the aspect obtained by such combination exhibits the effects based on each combined matter and also exhibits the synergistic effects of two or more combined matters.

[0100] In the present disclosure, various non-limiting aspects including Aspects 1 to 19 are described. In the present disclosure, exemplary aspects of an ophthalmic device, an exemplary aspect of a method for controlling an ophthalmic device, an exemplary aspect of a program, and an exemplary aspect of a recording medium are mainly described. However, the category of aspects of the embodiments is not limited to these. For example, those skilled in the art will be able to understand that the embodiments according to the present disclosure can provide various aspects of medical methods, various aspects of imaging methods, various aspects of data processing methods, and the like.

[0101] <Ophthalmic device> Regarding the ophthalmic device according to the embodiment, some non-limiting exemplary aspects will be described. The ophthalmic device according to the embodiment may include any type of anterior eye scanner. In the present disclosure, some examples of a slit lamp microscope configured to enable anterior eye scanning will be described in detail, but the method of anterior eye scanning and the applicable configurations are not limited to these examples.

[0102] FIG. 1 shows a configuration example of an ophthalmic device according to one aspect. The ophthalmic device 1 of this aspect is used for anterior eye imaging of the eye E to be examined, and includes a scan unit 2, a fixation optical system 3, a movement mechanism 6, a control unit 7, a data processing unit 8, a communication unit 9, and a user interface (UI) 10. The cornea of the eye E to be examined is indicated by the reference symbol Co, the iris by the reference symbol Ir, and the lens by the reference symbol Cr.

[0103] In accordance with the convention in the field of ophthalmology, the direction along the axis of the eye E to be examined is defined as the Z direction (Z axis), and the plane perpendicular to the Z direction is defined as the XY plane. The left - right direction (horizontal direction) for the subject is defined as the X direction (X axis), and the direction perpendicular to both the X direction and the Z direction (vertical direction, body - axis direction) is defined as the Y direction (Y axis).

[0104] Reference numeral 2a indicates the optical axis of the optical system included in the scanning unit 2 (referred to as the scanning optical axis). The scanning optical axis 2a is arranged parallel to the Z axis. Reference numeral 3a indicates the optical axis of the fixation optical system 3 (referred to as the fixation optical axis). The fixation optical axis 3a is arranged at an angle θ with respect to the Z axis (illumination optical axis 21a) in the Y direction. That is, the scanning unit 2 and the fixation optical system 3 are arranged in a positional relationship such that the scanning optical axis 2a and the fixation optical axis 3a form an angle θ in the Y direction. The inclination direction of the fixation optical axis 3a with respect to the scanning optical axis 2a may be upward or downward. Also, this inclination angle may be variable.

[0105] In another aspect, the scanning unit and the fixation optical system may be arranged such that the scanning optical axis and the fixation optical axis coincide. In that case, for example, an optical path coupling element (e.g., a half - mirror) co - axially couples the optical path of the scanning unit and the optical path of the fixation optical system.

[0106] The communication unit 9 performs data communication between the ophthalmic device 1 and other devices. That is, the communication unit 9 transmits data to other devices and receives data transmitted from other devices. The data communication method executed by the communication unit 9 is arbitrary. For example, the communication unit 9 includes one or more of various communication interfaces such as a communication interface compliant with the Internet, a communication interface compliant with a dedicated line, a communication interface compliant with a LAN, and a communication interface compliant with short - range communication. The data communication may be wired communication or wireless communication.

[0107] The data transmitted or received by the communication unit 9 may be encrypted data. The control unit 7 and / or the data processing unit 8 may include either or both of an encryption processing unit that encrypts the data transmitted by the communication unit 9 and a decryption processing unit that decrypts the data received by the communication unit 9.

[0108] The user interface 10 includes any user interface device such as a display device and an operation device. Users such as doctors, examinees, and assistants can operate the ophthalmic apparatus 1 and input information into the ophthalmic apparatus 1 by using the user interface 10. At least a part of the user interface 10 may be a peripheral device of the ophthalmic apparatus 1.

[0109] The display device displays various information under the control of the control unit 7. The display device may include a flat panel display such as a liquid crystal display (LCD). The operation device includes a device for operating the ophthalmic apparatus 1 and a device for inputting information. The operation device includes, for example, buttons, switches, levers, dials, handles, knobs, mice, keyboards, trackballs, operation panels, and the like. A device in which the display device and the operation device are integrated, such as a touch screen, may be used.

[0110] The scanning unit 2 is configured to apply a anterior eye scan using visible light (visible illumination light) to the eye to be examined 3 and collect a plurality of anterior eye images (anterior eye image group).

[0111] One example of the scanning unit 2 is shown in FIG. 2. FIG. 2 is a view of the scanning unit 2 as seen from above (top view). The scanning unit 2 in this example includes an illumination system 21, two imaging systems 22L and 22R, and a scanning mechanism 23. The illumination system 21 projects visible illumination light onto the anterior eye part of the eye E to be examined. The imaging system 22L images the anterior eye part onto which the visible illumination light has been projected. Similarly, the imaging system 22R images the anterior eye part onto which the visible illumination light has been projected. The scanning mechanism 23 of this example moves the unit 20 including the illumination system 21 and the imaging systems 22L and 22R. That is, the scanning mechanism 23 moves the illumination system 21 and the imaging systems 22L and 22R integrally without moving the fixation optical system 3.

[0112] The optical axis (illumination optical axis) 21a of the illumination system 21 is arranged parallel to the Z axis. The optical axis (imaging optical axis) 22La of the imaging system 22L is inclined by an angle θL in a first direction (+X direction or -X direction) defined by the X axis with respect to the illumination optical axis 21a. On the other hand, the optical axis (imaging optical axis) 22Ra of the imaging system 22R is inclined by an angle θR in a second direction (-X direction or +X direction) opposite to the first direction with respect to the illumination optical axis 21a. The angle θL and the angle θR may be equal to each other or different from each other.

[0113] The illumination optical axis 21a and the two imaging optical axes 22La and 22Ra are all arranged on the ZX plane. The scanning unit 2 is shown as a side view in FIG. 1 and as a top view in FIG. 2, respectively. The scanning optical axis 2a in FIG. 1 corresponds to the illumination optical axis 21a and the two imaging optical axes 22La and 22Ra in FIG. 2. The fixation optical axis 3a in FIG. 1 is arranged inclined by an angle θ in the Y direction with respect to each of the illumination optical axis 21a and the two imaging optical axes 22La and 22Ra.

[0114] Thus, the fixation optical system 3 projects fixation light onto the eye E to be examined from a direction different from both the projection direction of the visible illumination light onto the anterior eye part by the illumination system 21 and the imaging direction of the anterior eye part by the imaging systems 22L and 22R. As described above, in an example embodiment where the scan unit and the fixation optical system are arranged such that the scan optical axis and the fixation optical axis coincide, that is, in an example embodiment where the scan unit and the fixation optical system are configured as a coaxial optical system, the fixation optical system projects fixation light onto the eye E to be examined from the same direction as the projection direction and / or the imaging direction of the visible illumination light.

[0115] At least one of the combinations of the illumination system 21 and the imaging system 22L and the combination of the illumination system 21 and the imaging system 22R may be configured as a shine-proof optical system that satisfies the shine-proof condition.

[0116] One non-limiting example of the configuration described above is described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2023-49320) by the applicant of the present application. The scan unit 2 and the fixation optical system 3 of this embodiment may have the same configuration as the slit lamp microscope described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2023-49320).

[0117] When adopting the configuration of Patent Document 1 (Japanese Patent Application Laid-Open No. 2023-49320), the scan unit 2 has the following configuration in order to perform an anterior eye part scan of the eye E to be examined using slit light as visible illumination light.

[0118] The illumination system 21 includes an illumination light source that generates visible light, a slit forming unit that forms a slit opening for converting the generated visible light into slit light, an objective lens that projects the formed slit light onto the anterior eye part of the eye E to be examined, and the like.

[0119] The imaging system 22L includes an optical system including an objective lens, a zoom optical system, an imaging lens, etc., and an imaging element that detects the light guided by this optical system. The imaging element is an area sensor such as a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. The imaging system 22R has the same configuration as the imaging system 22L.

[0120] The illumination system 21 and the imaging system 22L form a shine-proof optical system. That is, the illumination system 21 and the imaging system 22L are configured such that the object plane including the illumination optical axis 21a, the principal plane of the optical system of the imaging system 22L, and the imaging plane of the imaging element intersect on the same straight line. The same applies to the combination of the illumination system 21 and the imaging system 22R.

[0121] The shape of the projected image of the slit light formed on the anterior eye part by the illumination system 21 is a narrow band shape with the Y direction as the longitudinal direction (slit length direction) and the X direction as the short direction (slit width direction). The scanning mechanism 23 moves the illumination system 21 and the imaging systems 22L and 22R integrally in the X direction. The scanning mechanism 23 includes an actuator such as a motor and a mechanism for moving the illumination system 21 and the imaging systems 22L and 22R by the driving force generated by this actuator.

[0122] The scanning unit 2 executes a scan of the anterior eye part using slit light by combining the projection of slit light by the illumination system 21, multiple imaging operations (time-series imaging, video imaging, iterative imaging) by the imaging systems 22L and 22R, and the integral movement of the illumination system 21 and the imaging systems 22L and 22R by the scanning mechanism 23. As a result, while moving the projection area (object plane) of the slit light in the X direction, multiple oblique imaging operations by the imaging systems 22L and 22R can be executed, and a series of anterior eye part images (anterior eye part image group) can be collected. Each anterior eye part image depicts a cross-section corresponding to the projection area of the slit light.

[0123] On the other hand, when adopting the configuration of Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-49320), the fixation optical system 3 projects fixation light onto the eye to be examined E (fundus) from a direction inclined by an angle θ in the Y direction (upward or downward) with respect to the scanning optical axis 2a, and includes a fixation light source, a diffusion plate, a pinhole member, a first lens, a cross reticle plate, and a second lens.

[0124] The fixation light source generates green light as visible light. The generated visible light is diffused by a diffuser plate and then projected onto a pinhole member. The visible light that passes through the aperture (pinhole) formed in the pinhole member is projected onto a cross reticle plate via a first lens. The visible light that passes through the cross-shaped light-transmitting portion formed in the cross reticle plate is guided to the eye E to be examined via a second lens. The subject can visually recognize the cross-shaped fixation light (fixation target).

[0125] By adopting the configuration of Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-49320), it is possible to perform an anterior eye scan with a deep depth of field while fixing the eye E to be examined. In this aspect, by improving the stability of the line of sight (in other words, improving the certainty of fixation) during such an anterior eye scan, the quality of the anterior eye image group obtained by the anterior eye scan is improved, and the labor and burden of re-photographing are reduced or eliminated.

[0126] Returning to the reference of FIG. 1. The moving mechanism 6 moves the scan unit 2 and the fixation optical system 3. The moving mechanism 6 may be capable of moving the scan unit 2 and the fixation optical system 3 three-dimensionally (that is, in the X direction, Y direction, and Z direction), and is used for alignment, tracking, etc.

[0127] The control unit 7 controls each part of the ophthalmic apparatus 1. For example, the control unit 7 controls elements of the illumination system 21 (such as an illumination light source, optical elements, mechanisms, etc.), elements of the imaging systems 22L and 22R (such as image sensors, optical elements, mechanisms, etc.), the moving mechanism 6, the data processing unit 8, the communication unit 9, the user interface 10, etc.

[0128] The control unit 7 includes a processor, a main storage device, an auxiliary storage device, etc. The auxiliary storage device stores computer programs such as various control programs. These computer programs may be stored in a computer or storage device accessible by the ophthalmic apparatus 1. The functions of the control unit 7 are realized by the cooperation of software such as control programs and hardware such as processors.

[0129] The data processing unit 8 executes various data processes. The data to be processed may be either data acquired by the ophthalmic device 1 or data input from the outside.

[0130] The data processing unit 8 includes a processor, a main storage device, an auxiliary storage device, etc. The auxiliary storage device stores computer programs such as various data processing programs. These computer programs may be stored in a computer or a storage device accessible by the ophthalmic device 1. The functions of the data processing unit 8 are realized by the cooperation of software such as data processing programs and hardware such as a processor.

[0131] One non-limiting example of the data processing unit 8 is shown in FIG. 3. This example can be adopted when the ophthalmic device 1 determines the scanning range for the anterior eye segment of the eye E to be examined. In other words, as described above, this example can be adopted when the ophthalmic device 1 determines the modulation timing of the fixation light projected onto the eye E to be examined.

[0132] The data processing unit 8 in FIG. 3 includes a scanning range determination unit 81. The scanning range determination unit 81 determines the scanning range of the pupil region and the scanning range of the non-pupil region. The pupil region is a region including at least a part of the pupil of the eye E to be examined.

[0133] The pupil region is a region of the anterior eye segment such that at least a part of the visible illumination light projected onto the anterior eye segment of the eye E to be examined is projected onto the fundus through the pupil. On the other hand, the non-pupil region is a region that does not include the pupil of the eye E to be examined, in other words, a region of the anterior eye segment that does not have a common part (intersection part) with the pupil. The non-pupil region is a region of the anterior eye segment such that all of the visible illumination light projected onto the anterior eye segment of the eye E to be examined is blocked by the iris or the like, and no visible illumination light is projected onto the fundus through the pupil.

[0134] Fig. 4 shows one non-limiting example of the scanning range determined by the scanning range determination unit 81. As described above, when the configuration of Patent Document 1 (Japanese Patent Application Laid-Open No. 2023-49320) is adopted, the shape of the projected image of the visible illumination light (slit light) formed on the anterior eye part by the illumination system 21 is a narrow band shape with the Y direction as the longitudinal direction and the X direction as the short transverse direction, and the scanning mechanism 23 moves the illumination system 21 and the imaging systems 22L and 22R integrally in the X direction to perform anterior eye part scanning.

[0135] Reference numeral 11 in Fig. 4 indicates the entire range (full scanning range) to which such anterior eye part scanning is applied. The full scanning range 11 is composed of a plurality of partial scanning ranges 11(k) (k = 1, 2, ···, K). In the anterior eye part scanning of this example, by performing imaging once in sequence for the K partial scanning ranges 11(k), K images corresponding to the plurality of partial scanning ranges 11(k) are collected respectively. That is, the K partial scanning ranges (k) correspond to the application locations of the K times of imaging performed in the anterior eye part scanning of this example.

[0136] In Fig. 4, the region Ep indicated by the slanted lines in the eye to be examined E is the pupil. Among the K partial scanning ranges 11(k), the region composed of the partial scanning ranges 11(k1) to 11(k2) having a common part with the pupil Ep corresponds to the scanning range of the pupil region. Also, the region composed of the partial scanning ranges 11(1) to 11(k1 - 1) having no common part with the pupil Ep, and the region composed of the similar partial scanning ranges 11(k2 + 1) to 11(K) correspond to the scanning ranges of the non-pupil regions. Here, the following relationship holds: 1 ≦ k1 < k2 ≦ K.

[0137] In the example of FIG. 4, the scan range of each non-pupil region is defined as a connected region, but a region obtained as the sum of two or more connected regions may be defined as the scan range of one non-pupil region. That is, in this example, the connected region composed of the partial scan ranges 11(1) to 11(k1-1) is set as the scan range of one non-pupil region, and the connected region composed of the partial scan ranges 11(k2+1) to 11(K) is set as the scan range of one non-pupil region. However, a non-connected region composed of the partial scan ranges 11(1) to 11(k1-1) and 11(k2+1) to 11(K) may be set as the scan range of one non-pupil region. The same applies to the scan range of the pupil region.

[0138] Some non-limiting examples of the process executed by the scan range determination unit 81 to set such a scan range of the pupil region and a scan range of the non-pupil region will be described below.

[0139] The scan range determination unit 81 may be configured to determine a scan range of the pupil region and a scan range of the non-pupil region based on the pupil size of the eye E to be examined.

[0140] The pupil size may be any of the pupil size parameters described above, or another parameter. In the field of ophthalmology, the diameter of the pupil (pupil diameter) is often used as a parameter representing the size of the pupil. The measurement of the pupil diameter typically includes a process of identifying an image region corresponding to the pupil (pupil contour) from the anterior eye image (segmentation), a process of applying a graphic approximation (circle approximation or ellipse approximation) to the identified image region, and a process of calculating the diameter of the obtained approximate circle or approximate ellipse.

[0141] Also, the conditions of the anterior eye scan are set in advance or at the time of examination. For example, the shape and size of the entire scan range and the arrangement of a plurality of partial scan ranges constituting the entire scan range are set in advance or at the time of examination.

[0142] The scan range determination unit 81 can determine the scan range of the pupil region and the scan range of the non-pupil region based on the conditions of the anterior eye segment scan and the pupil diameter of the eye to be examined. For example, the scan range determination unit 81 assumes a state where the center of the entire scan range coincides with the pupil center (that is, by assuming a state where alignment in the XY direction is performed), and after performing alignment between the anterior eye segment and the entire scan range, it obtains the intersection state between the circular region (the region corresponding to the pupil) obtained from the pupil diameter and the entire scan range (a plurality of partial scan ranges), thereby determining the scan range of the pupil region and the scan range of the non-pupil region.

[0143] In another example, the scan range determination unit 81 may be configured to determine the scan range of the pupil region and the scan range of the non-pupil region based on the pupil size of the eye to be examined E and the start position and end position of the anterior eye segment scan applied to the eye to be examined E by the scan unit 2.

[0144] When applying this example to the exemplary scan range in FIG. 4, the start position and end position of the anterior eye segment scan are two coordinates on the X-axis. Specifically, they are a pair of the X coordinate indicating the partial scan range 11(1) and the X coordinate indicating the partial scan range 11(K). The scan range determination unit 81, for example, assumes a state where the X coordinate located at the midpoint of the two X coordinates coincides with the pupil center (that is, by assuming a state where alignment in the X direction is performed), specifies the section on the X-axis corresponding to the pupil diameter (the section on the X-axis centered on the X coordinate of the pupil center and having a length equal to the pupil diameter), and determines the scan range of the pupil region and the scan range of the non-pupil region by considering the intersection state with respect to the specified section.

[0145] In yet another example, the ophthalmic device 1 can obtain the pupil size using the observation image of the anterior eye segment of the eye to be examined E. As shown in FIG. 5, the ophthalmic device 1 in this example includes an observation system 4. The observation system 4 captures a moving image of the anterior eye segment of the eye to be examined E to generate an observation image. The observation system 4 is moved together with the scan unit 2 and the fixation optical system 3 by a moving mechanism 6.

[0146] The observation system 4 may be configured coaxially with the fixation optical system 3, similar to Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-49320). In that case, the observation system 6 includes an optical system and an imaging device (area sensor). The optical system includes, for example, an objective lens, a zoom optical system, an imaging lens, and the like. The observation system 4 may further include an observation illumination system that projects observation illumination light onto the anterior eye part of the eye E to be examined. The illumination system 21 of the scanning unit 2 may be used as the observation illumination system. The observation system 6 guides the return light of the observation illumination light projected onto the anterior eye part of the eye E to the imaging device by the optical system. The optical path of the observation system 4 and the optical path of the fixation optical system 3 are coupled by an optical path coupling element such that the optical axis (observation optical axis) of the observation system 4 and the fixation optical axis 3a intersect. The observation illumination light is typically infrared light (near-infrared light), but may also be visible light. As the optical path coupling element, for example, a dichroic mirror or a half mirror is used.

[0147] As shown in FIG. 6, the data processing unit 8 of the ophthalmic apparatus 1 in this example includes a scan range determination unit 81 and an alignment processing unit 82.

[0148] The alignment processing unit 82 analyzes the observation image generated by the observation system 4 to obtain the relative position of the scanning unit 2 (the illumination system 21 and the imaging systems 22L and 22R) with respect to the eye E to be examined. As described above, the relative position between the scanning unit 2 and the fixation optical system 3 is known, and since the fixation optical system 3 and the observation system 4 are arranged coaxially, obtaining the relative position of the scanning unit 2 with respect to the eye E to be examined is equivalent to obtaining the relative position of the fixation optical system 3 with respect to the eye E to be examined and the relative position of the observation system 4 with respect to the eye E to be examined.

[0149] The alignment processing unit 82 may be configured to analyze the observation image and detect the feature points of the anterior eye segment. For example, the alignment processing unit 82 applies segmentation to the observation image to identify the image region corresponding to the pupil, applies circular approximation or elliptical approximation to this image region, and obtains the center of the resulting approximated circle or approximated ellipse. The obtained center is used as the pupil center, which is an example of one of the feature points of the anterior eye segment. The alignment processing unit 82 obtains the deviation (relative position) of the detected feature point with respect to a preset allowable range of alignment error (referred to as an alignment mark, etc.). Obtaining this deviation is synonymous with obtaining the movement conditions (movement direction and movement amount) of the scan unit 2 for arranging the pupil center within this allowable range.

[0150] The control unit 7 controls the movement mechanism 6 based on the deviation or movement conditions obtained by the alignment processing unit 82. Thereby, the illumination system 21 of the scan unit 2 and the imaging systems 22L and 22R are arranged at positions suitable for anterior eye segment scanning of the eye to be examined E. In this example, the combination of the control unit 7 and the alignment processing unit 82 functions as the aforementioned alignment unit.

[0151] The alignment described above is the alignment in the XY direction (XY alignment). The method of XY alignment is not limited to the above, and for example, there are methods using alignment indicators, methods using Purkinje images, methods using stereo cameras, and the like. The ophthalmic device 1 may be configured to perform manual XY alignment instead of or in addition to such an automatic XY alignment method.

[0152] Also, the ophthalmic device 1 may be capable of performing alignment in the Z direction (Z alignment). The method of Z alignment may be arbitrary, and for example, there are methods using optical levers, methods using stereo cameras, and the like. The ophthalmic device 1 may be configured to perform manual Z alignment instead of or in addition to such an automatic Z alignment method.

[0153] Generally, in alignment, imaging is performed to detect the relative position of the device optical system with respect to the eye E to be examined. In this example, an observation image is acquired by the observation system 4. Further, in this example, the observation image generated by the observation system 4 during or after the execution of alignment is provided to the scan range determination unit 81. The provided observation image may be at least one frame.

[0154] The scan range determination unit 81 analyzes the observation image acquired during or after the execution of alignment to obtain the pupil size of the eye E to be examined. The method of this process may be the same as the method described above. Further, the scan range determination unit 81 determines the scan range of the pupil region and the scan range of the non-pupil region based on the pupil size thus obtained. Alternatively, the scan range determination unit 81 determines the scan range of the pupil region and the scan range of the non-pupil region based on the pupil size thus obtained and the start position and end position of the scan. The methods of these processes may be the same as the methods described above.

[0155] As described above, in this example, the scan range is determined using the observation image acquired during or after the execution of alignment. It may be arbitrary at which point the acquired observation image is provided for the determination of the scan range, but each has its merits. When the observation image acquired during the execution of alignment is used, there is a merit that it is not necessary to perform the operation of acquiring the observation image after the completion of alignment. On the other hand, when the observation image acquired after the execution of alignment is used, since the relative positional relationship between the eye E to be examined and the scan unit 2 is (substantially) a predetermined relationship (a state where the alignment is correct), there is a merit that the calculation becomes easy. Considering these, for example, by using the observation image acquired at the completion time of alignment, both merits can be enjoyed. Alternatively, the observation image acquired at the point when the alignment error is below a predetermined value may be used.

[0156] The ophthalmic apparatus 1 of this aspect may be capable of performing tracking that causes the optical system to follow the movement of the eye E to be examined. As shown in FIG. 7, the data processing unit 8 of this example includes an image analysis unit 83.

[0157] The control unit 7 provides the observation image generated by the observation system 4 to the image analysis unit 83 in real time. For example, the control unit 7 may sequentially send all the frames sequentially generated by the observation system 4 to the image analysis unit 83, or may sequentially send only the frames selected by the decimation process to the image analysis unit 83.

[0158] The image analysis unit 83 analyzes the observation image generated by the observation system 4 to obtain the time-series change in the relative position of the scan unit 2 (the illumination system 21 and the imaging systems 22L and 22R) with respect to the eye E to be examined. For example, the image analysis unit 83 can sequentially obtain the relative position of the scan unit 2 with respect to the eye E to be examined by sequentially applying the same process as the process executed by the alignment processing unit 82 to each of the sequentially input frames. Thereby, the time-series change in the relative position can be obtained.

[0159] The relative position sequentially and in real time obtained by the image analysis unit 83 is sequentially sent to the control unit 7 in real time. The control unit 7 controls the movement mechanism 6 sequentially and in real time so as to cancel the sequentially input relative position (tracking control). Thereby, the ophthalmic apparatus 1 of this example can perform tracking that causes the optical system to follow the movement of the eye E to be examined.

[0160] Furthermore, the control unit 7 of this example can concurrently execute tracking control for causing the scan unit 2 (the illumination system 21 and the imaging systems 22L and 22R) to follow the movement of the eye E to be examined, scan control for causing the scan unit 2 to perform an anterior eye scan, and fixation control for modulating the fixation light in the fixation optical system 3. Thereby, it becomes possible to perform the anterior eye scan of the eye E to be examined and the modulation of the fixation light while automatically and in real time adjusting the position of the scan unit 2 in accordance with the movement of the eye E to be examined.

[0161] In addition to the image analysis unit 83, the data processing unit 8 of this example may further include an alignment processing unit 82. As described above, alignment and tracking can be said to be similar operations in terms of aligning the position with respect to the eye to be examined E. That is, alignment is the initial alignment, and tracking is the repetitive alignment for maintaining the state achieved by alignment. Therefore, the alignment processing unit 82 may be configured to function as the image analysis unit 83, or the image analysis unit 83 may be configured to function as the alignment processing unit 82. That is, the alignment processing unit 82 and the image processing unit 83 may be the same element.

[0162] Some non-limiting operation examples of the ophthalmic apparatus 1 of this aspect will be further described with reference to FIGS. 8 and 9.

[0163] First, the face of the subject is placed on the face holding part (forehead rest, chin rest) (not shown) of the ophthalmic apparatus 1. The ophthalmic apparatus 1 receives an instruction operation made using, for example, the user interface 10, starts projecting fixation light onto the eye to be examined E that is the subject of the anterior eye scan (S1), and executes alignment (S2). The projection of the fixation light in step S1 is executed, for example, by the control unit 7 turning on a fixation light source (not shown) of the fixation optical system 3. The alignment in step S2 is executed, for example, by the cooperative processing between the alignment processing unit 82 and the control unit 7 described with reference to FIG. 6.

[0164] When the alignment in step S2 is completed, the ophthalmic apparatus 1 starts tracking to cause the scan unit 2 (the illumination system 21 and the imaging systems 22L and 22R) to follow the movement of the eye to be examined E (S3). The tracking is executed, for example, by the cooperative processing between the image analysis unit 83 and the control unit 7 described with reference to FIG. 7.

[0165] In parallel with step S3 or after step S3, the ophthalmic apparatus 1 determines the scanning range of the pupil region and the scanning range of the non-pupil region (S4). The determination of these scanning ranges is executed, for example, by the scanning range determination unit 81 described with reference to FIG. 3 or FIG. 6. The process executed by the scanning range determination unit 81 in step S4 may be any one of the several process examples described above. Information indicating the scanning range of the pupil region and the scanning range of the non-pupil region determined in step S4 is stored, for example, in a storage device (not shown) of the control unit 7.

[0166] The ophthalmic apparatus 1 starts applying a front-eye scan to the eye E to be examined in response to a predetermined imaging trigger (S5). The imaging trigger may be, for example, an instruction operation using the user interface 10, the completion of the alignment in step S2, the start of the tracking in step S3, or the completion of the scanning range determination process in step S4. The front-eye scan in step S5 is executed according to the scanning control described above and is also executed in parallel with the tracking control started in step S3.

[0167] In this operation example, as shown in FIG. 9, the entire front-eye part of the eye E to be examined is scanned from the inner corner side to the outer corner side (or from the outer corner side to the inner corner side). The symbol Ps indicates the scan start position, and the symbol Pe indicates the scan end position. Therefore, the front-eye scan in step S5 is performed from the scan start position Ps to the scan end position Pe.

[0168] The value of the fixation light amount at the start time of the front-eye scan in step S5 is "B1". The light amount value B1 may be set in advance. The light amount value B1 may or may not be equal to the light amount of the fixation light whose projection was started in step S1. For example, the light amount of the fixation light may or may not be changed in response to the start of the front-eye scan.

[0169] The section from the scan start position Ps to the scan position P1 is the scan range of the non-pupil region. The section from the scan position P1 to the scan position P2 is the scan range of the pupil region. The section from the scan position P2 to the scan end position Pe is the scan range of the non-pupil region.

[0170] While the ophthalmic device 1 is scanning the section from the scan start position Ps to the scan position P1, the ophthalmic device 1 continues to project the fixation light with the light quantity value B1 onto the eye E to be examined (S6: No).

[0171] When the application position of the anterior eye scan reaches the scan position P1 (S6: Yes), the ophthalmic device 1 switches the light quantity of the fixation light projected onto the eye E to be examined from the light quantity value B1 to the light quantity value B2 (S7). The light quantity value B2 is larger than the light quantity value B1. The light quantity value B2 may be preset. The fixation light quantity switching in step S7 is executed according to the fixation control described above.

[0172] While the ophthalmic device 1 is scanning the section from the scan position P1 to the scan position P2, the ophthalmic device 1 continues to project the fixation light with the light quantity value B2 onto the eye E to be examined (S8: No).

[0173] When the application position of the anterior eye scan reaches the scan position P2 (S8: Yes), the ophthalmic device 1 switches the light quantity of the fixation light projected onto the eye E to be examined from the light quantity value B2 to the light quantity value B1 (S9). The fixation light quantity switching in step S9 is executed according to the fixation control described above.

[0174] When the application position of the anterior eye scan reaches the scan end position Pe, the ophthalmic device 1 ends the anterior eye scan (S10). A series of anterior eye images collected by the scan unit 2 during steps S5 to S10 are, for example, saved, displayed, and transmitted. Thus, this operation example ends (end).

[0175] In this operation example, the fixation light quantity is decreased from the light quantity value B2 to the light quantity value B1 in step S9. However, the scanning may be performed up to the scan end position Pe with the light quantity value B2 remaining unchanged without performing this fixation light quantity switching. Alternatively, in step S9, the fixation light quantity may be switched from the light quantity value B2 to the light quantity value B3 (B3 < B2 and B3 ≠ B1).

[0176] As described above, this operation example provides one non-limiting example of the case where scan control, fixation control, and tracking control are executed in parallel. Those skilled in the art will be able to understand the operation of the ophthalmic device 1 when tracking is not performed, the operation of the ophthalmic device 1 when the scan range is not determined, and the operation of the ophthalmic device 1 when a scan range different from that in FIG. 9 is applied, from this operation example.

[0177] Also, in this operation example, the pupil region may be determined in consideration of miosis of the eye E to be examined. In that case, in order to measure the pupil size (pupil diameter) during miosis, for example, after alignment, visible illumination light or fixation light having a sufficiently large light quantity B0 (B1, B3 < B2 <<< B0) may be projected onto the eye E to be examined to promote miosis, and the pupil size may be measured in that state. This makes it possible to measure the pupil size more accurately.

[0178] As described above, the ophthalmic device 1 of this aspect may be configured such that the scan unit and the fixation optical system can be arranged so that the scan optical axis and the fixation optical axis coincide. Such an ophthalmic device 1 will be further described with reference to FIGS. 10 to 12. The ophthalmic device 1 of this example performs anterior eye segment scanning and fixation light modulation in parallel in any of the above-described aspects.

[0179] The scanning unit 2 of the ophthalmic apparatus 1 in this example shown in FIG. 10 includes the illumination system 21, the imaging systems 22L and 22R, and the scanning mechanism 23 of FIG. 2. Further, the scanning unit 2 of this example includes an optical path coupling element 5 that couples the optical path of the scanning unit 2 and the optical path of the fixation optical system 3. The optical path of the scanning unit 2 coupled to the optical path of the fixation optical system 3 by the optical path coupling element 5 may be the optical path of the illumination system 21 (illumination optical path) or the optical path of the imaging system 22L or 22R (imaging optical path).

[0180] The optical path coupling element 5 is, for example, a half mirror that is disposed in an inclined direction with respect to both the optical path of the scanning unit 2 and the optical path of the fixation optical system 3, transmits visible illumination light from the scanning unit 2, and reflects the fixation light from the fixation optical system 3.

[0181] When the illumination system 21 is disposed in front of the eye E to be examined, the scanning optical axis 2a of the scanning unit 2 and the fixation optical axis 3a of the fixation optical system 3 intersect on the reflecting surface of the optical path coupling element 5 that reflects the fixation light. That is, in a state where the illumination system 21 is positioned in front of the eye E to be examined, the scanning unit 2 and the fixation optical system 3 are coaxially arranged by the optical path coupling element 5. The scanning optical axis 2a that intersects the fixation optical axis 3a is any one of the illumination optical axis 21a, the imaging optical axis 22La, and the imaging optical axis 22Ra.

[0182] FIG. 11 is a view of the optical path coupling element 5 viewed from the Y direction, which is disposed inclined with respect to both the optical path of the scanning unit 2 and the optical path of the fixation optical system 3. As shown in FIG. 11, in the optical path coupling element 5, a region 2b through which light (for example, slit light) guided by the scanning unit 2 passes and a region 3b where the fixation light from the fixation optical system 5 is reflected intersect.

[0183] In the anterior segment scan of the eye E to be examined, the scanning mechanism 23 moves the illumination system 21 and the imaging systems 22L and 22R integrally in a predetermined moving direction (scanning direction) by a predetermined moving distance (scanning length). As shown in FIG. 11, the dimension Lm of the optical path coupling element 5 in the scanning direction (X direction) is designed to be larger than the scanning length Ls.

[0184] The mode of the anterior eye segment scan in this example is shown in FIG. 12. In the mode of FIG. 12, the optical path coupling element 5 couples the optical path of the illumination system 21 and the optical path of the fixation optical system 3. Therefore, the visible illumination light VL from the illumination system 21 passes through the same region (the above-mentioned region 2b) of the optical path coupling element 5. The visible illumination light VL is slit light having the longitudinal direction in the Y direction and the short side direction in the X direction.

[0185] In the anterior eye segment scan, first, the illumination system 21 and the imaging systems 22L and 22R are arranged at the scan start position. At this time, as shown in the left figure in FIG. 12, the visible illumination light VL from the illumination system 21 passes through the center position of the optical path coupling element 5 in the X direction and is projected onto the eye to be examined E, while the fixation light FL from the fixation optical system 3 is reflected at the position on the left end side of the optical path coupling element 5 and is projected onto the eye to be examined E.

[0186] When the illumination system 21 and the imaging systems 22L and 22R are integrally moved in the X direction in the anterior eye segment scan, the position where the visible illumination light VL from the illumination system 21 passes through the optical path coupling element 5 does not change, but the position where the fixation light FL from the fixation optical system 3 is reflected by the optical path coupling element 5 moves to the right.

[0187] The middle figure in FIG. 12 shows the relationship between the position where the visible illumination light VL passes through the optical path coupling element 5 and the position where the fixation light FL is reflected by the optical path coupling element 5 when the illumination system 21 and the imaging systems 22L and 22R reach the center position (scan center position) of the scan range. At this time, the visible illumination light VL from the illumination system 21 passes through the center position of the optical path coupling element 5 in the X direction and is projected onto the eye to be examined E, while the fixation light FL from the fixation optical system 3 is also reflected at the center position of the optical path coupling element 5 and is projected onto the eye to be examined E. Therefore, the positions of both intersect.

[0188] The right diagram in Fig. 12 shows the relationship between the position where the visible illumination light VL passes through the optical path coupling element 5 and the position where the fixation light FL is reflected by the optical path coupling element 5 when the illumination system 21 and the imaging systems 22L and 22R reach the scan end position. At this time, the visible illumination light VL from the illumination system 21 passes through the center position of the optical path coupling element 5 in the X direction and is projected onto the eye E to be examined, while the fixation light FL from the fixation optical system 3 is reflected at the position on the right end side of the optical path coupling element 5 and is projected onto the eye E to be examined.

[0189] As described above, in addition to having a configuration in which the optical path of the scan unit 2 and the optical path of the fixation optical system 3 are combined, the ophthalmic apparatus 1 of this example can modulate the fixation light in parallel with the anterior eye scan while projecting the fixation light onto the eye E to be examined from the same direction from the start to the end of the anterior eye scan. Therefore, according to the ophthalmic apparatus 1 of this example, it is possible to improve the stability of the line of sight during the anterior eye scan while adopting a configuration in which the optical path of the scan unit 2 and the optical path of the fixation optical system 3 are combined.

[0190] As described above, some non-limiting aspects of the ophthalmic apparatus according to the embodiment have been described. It is possible to at least partially combine any two or more aspects.

[0191] <Other aspects> The embodiments according to the present disclosure are not limited to ophthalmic apparatuses. As embodiments other than ophthalmic apparatuses, there are a method of controlling an ophthalmic apparatus, a method of imaging the anterior eye, a program, a recording medium, and the like. Similar to the embodiments of the ophthalmic apparatus, these embodiments can also improve the image quality in anterior eye imaging.

[0192] Some embodiments provide a method for controlling an ophthalmic device. The ophthalmic device can be used to image the anterior segment of an eye to be examined and includes a scanning unit, a fixation optical system, and a processor. The scanning unit performs a scan of the anterior segment using visible light to collect an image. The fixation optical system projects fixation light onto the eye to be examined. The method according to this embodiment causes the processor to execute scan control for causing the scanning unit to perform a scan of the anterior segment, and causes the processor to execute fixation control for modulating the fixation light in the fixation optical system in parallel with the scan control.

[0193] Any matter described in the present disclosure can be combined with the method according to the embodiment.

[0194] Some embodiments provide a program. The program according to the embodiment causes a computer including a processor and a memory to execute the method according to the above-described embodiment. Any matter described in the present disclosure can be combined with the program according to the embodiment.

[0195] Some embodiments provide a computer-readable non-transitory recording medium. A program for causing a computer to execute the method according to the above-described embodiment is recorded on the recording medium according to the embodiment. Any matter described in the present disclosure can be combined with the recording medium according to the embodiment.

[0196] The computer-readable non-transitory recording medium that can be used as the recording medium according to this embodiment may be any form of recording medium, for example, any one of a magnetic disk, an optical disk, a magneto-optical disk, and a semiconductor memory.

[0197] The embodiments and aspects described in the present disclosure are merely examples. Any modification (omission, substitution, addition, etc.) within the scope of the gist of the present invention can be applied to the embodiments and aspects of the present disclosure.

Description of Reference Numerals

[0198] 1 Ophthalmic device 2 Scan Unit 21 Lighting System 22L, 22R Imaging System 23 Scanning Mechanism 3 Fixation Optical System 4 Observation System 6 Movement Mechanism 7 Control Unit 8 Data Processing Unit 81 Scanning Range Determination Unit 82 Alignment Processing Unit 83 Image Analysis Unit

Claims

1. A scan unit that executes a scan of the anterior segment of the eye to be examined using visible light and collects an image, A fixation optical system that projects fixation light onto the eye to be examined, A control unit and includes The control unit executes scan control to cause the scan unit to execute the scan, and executes fixation control to modulate the fixation light in the fixation optical system in parallel with the scan control. Ophthalmic apparatus.

2. In the fixation control, the control unit changes the light amount of the fixation light. The ophthalmic apparatus according to claim 1.

3. The control unit In the scan control, causes the scan unit to execute a scan of a non-pupil region that does not include the pupil of the anterior segment and a scan of a pupil region that includes the pupil, In the fixation control, causes the fixation optical system to generate the fixation light having a first light amount during execution of the scan of the non-pupil region, and causes the fixation optical system to generate the fixation light having a second light amount greater than the first light amount during execution of the scan of the pupil region. The ophthalmic apparatus according to claim 2.

4. The control unit In the scan control, causes the scan unit to execute, as a series of scans, a scan of a first non-pupil region located on a first side of the pupil between the temporal side and the nasal side, a scan of the pupil region, and a scan of a second non-pupil region located on a second side of the pupil between the temporal side and the nasal side, In the fixation control, switches the light amount of the fixation light from the first light amount to the second light amount in response to the transition from the scan of the first non-pupil region to the scan of the pupil region, and switches the light amount of the fixation light from the second light amount to the first light amount in response to the transition from the scan of the pupil region to the scan of the second non-pupil region. The ophthalmic apparatus according to claim 3.

5. In the fixation control, the control unit changes any one of the wavelength of the fixation light, the intensity modulation frequency of the fixation light, the light emission size of the fixation light, and the light emission shape of the fixation light. The ophthalmic apparatus according to claim 1.

6. The control unit In the scan control, causes the scan unit to perform a scan of a non-pupil region excluding the pupil of the anterior eye segment and a scan of a pupil region including the pupil. In the fixation control, causes the fixation optical system to generate the fixation light having characteristics different from each other during the execution of the scan of the non-pupil region and during the execution of the scan of the pupil region. The ophthalmic apparatus according to claim 1.

7. Further includes a scan range determination unit that determines the scan range of the non-pupil region and the scan range of the pupil region. The ophthalmic apparatus according to claim 6.

8. The scan range determination unit determines the scan range of the non-pupil region and the scan range of the pupil region based on the pupil size of the eye to be examined. The ophthalmic apparatus according to claim 7.

9. The scan range determination unit determines the scan range of the non-pupil region and the scan range of the pupil region based on the pupil size of the eye to be examined and the start position and end position of the scan applied to the anterior eye segment by the scan unit. The ophthalmic apparatus according to claim 8.

10. Further includes an observation system that captures a moving image of the anterior eye segment to generate an observation image, The scan range determination unit obtains the pupil size by analyzing the observation image. The ophthalmic apparatus according to claim 8.

11. The scan unit An illumination system that projects the visible light onto the anterior eye segment An imaging system that images the anterior eye part onto which the visible light is projected and includes a moving mechanism that moves the illumination system and the imaging system, an alignment unit that analyzes an observation image generated by the observation system to obtain a relative position of the illumination system and the imaging system with respect to the eye to be examined, and controls the moving mechanism based on the relative position to perform alignment of the illumination system and the imaging system with respect to the eye to be examined and further includes The scan range determination unit obtains the pupil size by analyzing an observation image generated by the observation system during or after the execution of the alignment. The ophthalmic device according to claim 10.

12. The scan unit includes an illumination system that projects the visible light onto the anterior eye part, and an imaging system that images the anterior eye part onto which the visible light is projected and includes The fixation optical system projects the fixation light onto the eye to be examined from a direction different from both the projection direction of the visible light by the illumination system onto the anterior eye part and the imaging direction of the anterior eye part by the imaging system. The ophthalmic device according to claim 1.

13. The illumination system and the imaging system are configured as a shine-proof optical system that satisfies shine-proof conditions, The scan unit further includes a scan mechanism that integrally moves the illumination system and the imaging system without moving the fixation optical system. The ophthalmic device according to claim 12.

14. The scan unit includes an illumination system that projects the visible light onto the anterior eye part, and an imaging system that images the anterior eye part onto which the visible light is projected and includes and further includes an optical path coupling element that couples the optical path of the fixation optical system to the optical path of the illumination system or the optical path of the imaging system. The ophthalmic device according to claim 1.

15. The illumination system and the imaging system are configured as a shine-proof optical system that satisfies the shine-proof conditions, The scan unit further includes a scan mechanism that integrally moves the illumination system and the imaging system without moving the fixation optical system, The dimension of the optical path coupling element in the moving direction of the illumination system and the imaging system by the scan mechanism is larger than the moving distance of the illumination system and the imaging system, The ophthalmic device according to claim 14.

16. The scan unit is An illumination system that projects the visible light onto the anterior eye segment, An imaging system that images the anterior eye segment onto which the visible light is projected and includes A moving mechanism that moves the illumination system and the imaging system, An observation system that captures a moving image of the anterior eye segment to generate an observation image, An image analysis unit that analyzes the observation image to obtain a time-series change in the relative position of the illumination system and the imaging system with respect to the eye to be examined and further includes The control unit executes tracking control to cause the illumination system and the imaging system to follow the movement of the eye to be examined by sequentially controlling the moving mechanism based on the time-series change in the relative position, in parallel with the scan control and the fixation control The ophthalmic device according to claim 1.

17. A method for controlling an ophthalmic device for photographing the anterior eye segment of an eye to be examined, the method comprising: The ophthalmic device includes A scan unit that performs a scan of the anterior eye segment using visible light to collect an image, A fixation optical system that projects fixation light onto the eye to be examined, A processor and includes Causing the processor to execute scan control for causing the scanning unit to perform the scan, and causing fixation control for modulating the fixation light on the fixation optical system to be executed in parallel with the scan control. Method.

18. A program for causing a computer to execute the method according to claim 17.

19. A computer-readable non-transitory recording medium on which the program according to claim 18 is recorded.

Images