JP7231405B2 - Ophthalmic device and its control method - Google Patents

Description

The present invention relates to an ophthalmic apparatus and its control method.

2. Description of the Related Art In recent years, optical coherence tomography (OCT), which uses a light beam from a laser light source or the like to measure and image the shape of an object, has attracted attention. Since OCT is not invasive to the human body like X-ray CT (Computed Tomography), it is expected to be applied particularly in the medical and biological fields. For example, in the field of ophthalmology, apparatuses for forming images of the fundus, cornea, etc. have been put to practical use. Such an apparatus using OCT (OCT apparatus) can be applied to observation of various parts of the subject's eye (fundus and anterior segment of the eye). In addition, since it can acquire high-definition images, it is applied to the diagnosis of various ophthalmic diseases.

In measurement (imaging) using OCT, it is required to acquire a wider-angle and higher-definition measurement result. For example, Patent Literature 1 and Patent Literature 2 disclose an ophthalmic apparatus using an ellipsoidal mirror. The ophthalmologic apparatuses disclosed in Patent Documents 1 and 2 are configured such that measurement light deflected by an optical scanner is reflected by an ellipsoidal mirror and guided to an eye to be examined.

JP 2018-61622 A Japanese Patent Application Laid-Open No. 2018-167000

When an ellipsoidal mirror is used, there is a nonlinear relationship between the deflection angle of the measurement light by the optical scanner and the incident angle of the measurement light at the position of the eye to be examined. Therefore, when the optical scanner is linearly deflected and A-scans are executed at substantially equal time intervals, the intervals between the angles of incidence of the measurement light beams at the positions of the eye to be inspected become uneven. That is, even if simple deflection control is performed on the optical scanner, it becomes difficult to obtain a highly accurate OCT measurement result at a desired measurement site.

The deterioration in the accuracy of OCT measurement results due to such non-uniform incident angle intervals of measurement light is not limited to ophthalmologic devices using ellipsoidal mirrors, but also to concave mirrors (reflecting surface The same applies to ophthalmic devices using a free curved surface.

The present invention has been made in view of such circumstances, and its object is to provide an ophthalmologic apparatus capable of wide-angle and highly accurate OCT measurement using a concave mirror, and a control method thereof.

A first aspect of some embodiments includes a concave mirror and an optical scanner that deflects and directs measurement light to a reflective surface of the concave mirror, using optical coherence tomography with measurement light reflected by the reflective surface. an acquisition unit that acquires data of the eye to be inspected by executing an A-scan on the eye to be inspected placed at a position of the eye to be inspected or a conjugate position thereof; and a controller for executing an A-scan.

In a second aspect of some embodiments, in the first aspect, the concave mirror is an ellipsoidal mirror, and the optical scanner is positioned at or near a first focal point of the ellipsoidal mirror, or at a conjugate of the first focal point. The position of the subject's eye is arranged at or near the second focal point of the ellipsoidal mirror, or at or near the conjugate position of the second focal point.

A third aspect of some embodiments is, in the first aspect or the second aspect, including a storage unit that stores in advance the timing information of the A-scan, and the control unit instructs the acquisition unit based on the timing information The A scan is executed.

In a fourth aspect of some embodiments, in the third aspect, the timing information includes A-scan timing information based on the reference timing of the deflection operation of the optical scanner, and the control unit receives the timing information causes the acquisition unit to execute the A-scan at the timing specified by.

In a fifth aspect of some embodiments, in the first aspect or the second aspect, the control section causes the acquisition section to execute the A-scan according to the deflection angle of the optical scanner.

In a sixth aspect of some embodiments, in the fifth aspect, the controller acquires operation information representing a deflection angle of the optical scanner, and the deflection angle is a predetermined deflection based on the acquired operation information. is an angle, and when it is determined that the deflection angle is the predetermined deflection angle, the acquisition unit is caused to execute the A-scan.

According to a seventh aspect of some embodiments, in any one of the first to sixth aspects, the control unit controls the acquisition unit so that intervals of incident angles of the measurement light at the positions of the subject's eyes are substantially equal. to execute the A scan.

According to an eighth aspect of some embodiments, in any one of the first to sixth aspects, the control unit instructs the acquisition unit such that the intervals between the projection positions of the measurement light on the eye to be inspected are substantially equal. The A scan is executed.

A ninth aspect of some embodiments is a method of controlling an ophthalmic device that includes a concave mirror and an optical scanner that deflects and directs measurement light to a reflective surface of the concave mirror, wherein the measurement light reflected by the reflective surface an acquisition step of acquiring data of the eye to be inspected by performing an A-scan on the eye to be inspected placed at the position of the eye to be inspected or its conjugate position using optical coherence tomography by optical coherence tomography; and a deflection operation state of the optical scanner and a control step of executing the A-scan in response to the ophthalmologic apparatus.

In a tenth aspect of some embodiments, in the ninth aspect, the concave mirror is an ellipsoidal mirror, and the optical scanner is positioned at or near a first focal point of the ellipsoidal mirror, or at a conjugate of the first focal point. The position of the subject's eye is arranged at or near the second focal point of the ellipsoidal mirror, or at or near the conjugate position of the second focal point.

In an eleventh aspect of some embodiments, in the ninth aspect or tenth aspect, the control step causes the A-scan to be performed based on pre-stored timing information for the A-scan.

In a twelfth aspect of some embodiments, in the eleventh aspect, the timing information includes A-scan timing information based on the reference timing of the deflection operation of the optical scanner, and the control step includes: The A-scan is executed at the timing specified by .

In a thirteenth aspect of some embodiments, in the ninth aspect or the tenth aspect, the controlling step causes the A-scan to be performed according to the deflection angle of the optical scanner.

In a fourteenth aspect of some embodiments, in the thirteenth aspect, the control step includes a motion information acquisition step of acquiring motion information representing a deflection angle of the optical scanner; a determination step of determining whether or not the angle is a predetermined deflection angle; and an execution step of executing the A-scan when it is determined in the determination step that the deflection angle is the predetermined deflection angle. include.

According to a fifteenth aspect of some embodiments, in any one of the ninth to fourteenth aspects, the controlling step performs the A-scan so that intervals of incident angles of the measurement light at the positions of the subject's eyes are substantially equal. to run.

According to a sixteenth aspect of some embodiments, in any one of the ninth to fourteenth aspects, the control step performs the A-scan so that intervals between the projection positions of the measurement light on the eye to be inspected are substantially equal. let it run.

Note that it is possible to arbitrarily combine the configurations according to the plurality of aspects described above.

Advantageous Effects of Invention According to the present invention, it is possible to provide an ophthalmologic apparatus capable of wide-angle and highly accurate measurement using a concave mirror, and a method of controlling the same.

1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment; FIG. 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment; FIG. 1 is a schematic block diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment; FIG. FIG. 5 is a schematic diagram for explaining the relationship between the deflection angle of measurement light by an optical scanner according to a comparative example of the embodiment and the incident angle of the measurement light at the position of the eye to be examined; FIG. 3 is a schematic diagram for explaining processing executed by an ophthalmologic apparatus according to an embodiment; FIG. 3 is a schematic diagram for explaining processing executed by an ophthalmologic apparatus according to an embodiment; FIG. 3 is a schematic diagram for explaining processing executed by an ophthalmologic apparatus according to an embodiment; 4 is a flowchart showing an operation example of the ophthalmologic apparatus according to the embodiment; FIG. 3 is a schematic diagram for explaining processing executed by an ophthalmologic apparatus according to an embodiment; 4 is a flowchart showing an operation example of the ophthalmologic apparatus according to the embodiment; 1 is a schematic diagram showing an example of the configuration of an ophthalmologic apparatus according to an embodiment; FIG.

Embodiments of an ophthalmologic apparatus and an ophthalmologic apparatus control method according to the present invention will be described in detail with reference to the drawings. It should be noted that the descriptions of the documents cited in this specification and any known techniques can be incorporated into the following embodiments.

An ophthalmologic apparatus according to an embodiment includes a concave mirror having a concave reflecting surface, and an optical scanner that deflects measurement light within a predetermined deflection angle range and guides it to the reflecting surface of the concave mirror. The ophthalmologic apparatus can perform OCT on the subject's eye placed at the subject's eye position or its conjugate position using optical coherence tomography using measurement light reflected by a reflective surface. At this time, the ophthalmologic apparatus acquires data of the subject's eye by performing OCT measurement (at least A-scan) at a timing corresponding to the deflection operation state of the optical scanner. Examples of the deflection operation state of the optical scanner include the deflection angle (deflection angle of the optical scanner) of the mirror (deflection member) that deflects the measurement light, the deflection frequency (deflection speed, deflection period) of the mirror, and the like. The deflection angle of the mirror can be determined, for example, from the preset deflection frequency for the mirror set to the given deflection angle.

As a result, a data set in the A-scan direction that takes into account the variation characteristics of the deflection angle of the measurement light by the optical scanner (deflection operation characteristics) and the variation characteristics of the incident angle of the measurement light at the position of the subject's eye due to the shape of the reflecting surface of the concave mirror. group can be obtained. For example, it is possible to acquire a data set group at scanning positions scanned at substantially equal scanning angles (deflection angles) or at substantially equal scanning intervals without being affected by the deflection operation characteristics of the optical scanner and the shape of the reflecting surface of the concave mirror. be possible.

In the embodiments below, a case where a swept source type OCT technique is used in measurement or imaging using OCT will be described in detail. However, it is also possible to apply the configuration according to the embodiment to an ophthalmic apparatus using OCT of another type (for example, spectral domain type).

A case where the optical scanner includes a galvanometer scanner will be described below. However, it is possible to apply the following embodiments even when the optical scanner includes a deflection member other than the galvanometer scanner. Further, although the deflection angle vs. time characteristic will be described below as an example of the operating characteristic of the optical scanner, the following embodiments can also be applied to other operating characteristics of the optical scanner.

In this specification, images obtained by OCT may be collectively referred to as OCT images. Also, the measurement operation for forming an OCT image is sometimes called OCT measurement.

An ophthalmic device according to some embodiments includes any one or more of an ophthalmic imaging device, an ophthalmic measurement device, and an ophthalmic treatment device. The ophthalmic imaging device included in the ophthalmic device of some embodiments is, for example, any one or more of a fundus camera, a scanning laser ophthalmoscope, a slit lamp ophthalmoscope, a surgical microscope, or the like. Also, ophthalmic measurement devices included in ophthalmic devices of some embodiments include, for example, any one or more of an eye refraction tester, a tonometer, a specular microscope, a wavefront analyzer, a perimeter, a microperimeter, and the like. is. Also, the ophthalmic treatment device included in the ophthalmic device of some embodiments is, for example, any one or more of a laser treatment device, a surgical device, a surgical microscope, and the like.

An ophthalmologic apparatus according to the following embodiments includes an OCT apparatus capable of OCT measurement. An ophthalmologic apparatus capable of performing OCT measurement on the fundus of the subject's eye will be described below as an example, but the ophthalmologic apparatus according to the embodiment may be capable of performing OCT measurement on the anterior segment of the subject's eye. In some embodiments, the range of OCT measurement and the measurement site are changed by moving a lens that changes the focal position of the measurement light. In some embodiments, by adding one or more attachments (objective lens, front lens, etc.), OCT measurement for the fundus, OCT measurement for the anterior segment, and OCT for the entire eye including the fundus and the anterior segment It is a configuration that allows measurement. In some embodiments, in an ophthalmologic apparatus for fundus measurement, a front lens is arranged between a collimator lens unit (described later) or an optical scanner and the eye to be examined, so that the measurement light is made into a parallel beam and directed to the eye to be examined. OCT measurement is performed on the anterior segment of the eye by making the light incident.

[First embodiment]
The ophthalmologic apparatus according to the first embodiment performs OCT measurement on the subject's eye by feedforward control.

<Configuration>
FIG. 1 shows a configuration example of an ophthalmologic apparatus according to an embodiment.

An ophthalmologic apparatus 1 according to the embodiment includes an optical system 10, a collimator lens unit 40, an OCT unit 100, an arithmetic control unit 200, and a display device 300. In some embodiments, OCT unit 100 includes collimator lens unit 40 . In some embodiments, optical system 10 includes collimator lens unit 40 and OCT unit 100 .

Optical system 10 includes an ellipsoidal mirror 11 and an optical scanner 20 . The reflecting surface of the ellipsoidal mirror 11 is an ellipsoid. The ellipsoidal mirror 11 is an example of a concave mirror. In some embodiments, instead of the ellipsoidal mirror 11, the optical system 10 includes a concave mirror having a concave reflecting surface. In some embodiments, the reflective surface of the concave mirror is formed to be a freeform surface.

The ellipsoidal mirror 11 has two optically conjugate focal points (first and second focal points). The optical scanner 20 (deflecting surface of the optical scanner 20) is arranged at or near the first focal point of the ellipsoidal mirror 11, or at or near a position optically conjugate with the first focal point (a conjugate position of the first focal point). be. The eye position to be examined where the eye to be examined E (pupil) is arranged is the second focal point of the ellipsoidal mirror 11 or its vicinity, or a position optically conjugated with the second focal point (the conjugate position of the second focal point) or its vicinity. placed.

The optical scanner 20 is arranged at a position optically conjugate with the pupil of the eye E to be examined or in the vicinity thereof. The optical scanner 20 deflects measurement light emitted from the collimator lens unit 40 (measurement light passing through the OCT optical path) within a predetermined deflection angle range. The optical scanner 20 can deflect measurement light one-dimensionally or two-dimensionally.

In the case of one-dimensional deflection, the optical scanner 20 includes a galvanometer scanner that deflects the measurement light in a given deflection direction and within a given deflection angle range. For two-dimensional deflection, the optical scanner 20 includes a first galvanometer scanner and a second galvanometer scanner. The first galvanometer scanner deflects the measurement light so as to scan the imaging site (fundus oculi Ef or anterior segment) in a horizontal direction perpendicular to the optical path (optical axis) of the measurement light. The second galvanometer scanner deflects the measurement light deflected by the first galvanometer scanner so as to scan the imaging region in a vertical direction orthogonal to the optical path (optical axis) of the measurement light. Scanning modes of the measurement light by the optical scanner 20 include, for example, horizontal scanning, vertical scanning, cross scanning, radial scanning, circular scanning, concentric scanning, and spiral scanning.

The optical scanner 20 is configured to be controllable by an arithmetic control unit 200 (control section 210 described later). In some embodiments, the optical scanner 20 is configured such that at least one of the deflection angle range and deflection frequency (deflection speed, deflection cycle) can be set by the arithmetic control unit 200 (control section 210). In some embodiments, the optical scanner 20 is configured such that information defining a control waveform for controlling the deflection operation can be set by the arithmetic control unit 200 (control section 210). The control waveform defines the deflection angle range and deflection frequency. The optical scanner 20 performs a deflection operation according to the set control waveform. The arithmetic control unit 200 (control section 210) can operate each of the first galvanometer scanner and the second galvanometer scanner in a desired deflection angle range or a desired deflection frequency.

In some embodiments, the optical scanner 20 receives control from the arithmetic control unit 200 (control section 210) and outputs operational information including the operational state of the optical scanner 20. FIG. The operation information includes information representing the deflection angle (for example, current value or voltage value corresponding to the deflection angle). In some embodiments, the optical scanner 20 includes a mirror that deflects the measurement light and a driver that drives the mirror, and the operational information includes information representing the deflection angle of the mirror. The arithmetic control unit 200 (control section 210) can monitor the operating states of the first galvanometer scanner and the second galvanometer scanner.

Collimator lens unit 40 includes a collimator lens arranged on the optical axis of the interference optical system included in OCT unit 100 . The collimator lens collimates the measurement light beam emitted from the end of the optical fiber that is connected to the OCT unit 100 and guides the measurement light beam. The end of the optical fiber is arranged, for example, at a position optically conjugate with the fundus Ef of the eye E to be examined or in the vicinity thereof.

In addition to the configuration shown in FIG. 1, the optical system 10 is provided with an optical system (observation optical system, photographing optical system, etc.) for photographing the subject's eye E (fundus oculi Ef or anterior segment) from the front and an alignment optical system. may be

The optical system 10 may also have a configuration for providing functions associated with inspection. For example, the optical system 10 may be provided with a fixation optical system for projecting a target (fixation target) for fixing the eye E to be examined onto the fundus Ef of the eye E to be examined. Further, a configuration for focusing the interference optical system included in the OCT unit 100 may be provided. Furthermore, the optical system 10 may include a light source for illuminating the anterior segment of the eye E to be examined (anterior segment illumination light source).

As will be described later, the OCT unit 100 is provided with an optical system (interference optical system) and part of a mechanism for performing OCT.

The arithmetic control unit 200 controls each part of the ophthalmologic apparatus 1 . The calculation control unit 200 includes one or more processors, and executes various calculations and controls by executing processes corresponding to pre-stored programs.

In this specification, the "processor" includes, for example, 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) Programmable Logic Device), FPGA (Field Programmable Gate Array)) or the like. The processor implements the functions according to the embodiment by, for example, reading and executing a program stored in a storage circuit or storage device.

The display device 300 displays various information. The display device 300 includes a display device such as a liquid crystal display, receives control from the arithmetic control unit 200, and displays the above information. The information displayed on the display device 300 includes information corresponding to the control result by the arithmetic control unit 200, information (image) corresponding to the arithmetic result by the arithmetic control unit 200, and information (image) acquired by an optical system (not shown). and so on.

In addition to these, the ophthalmologic apparatus 1 includes a member for supporting the subject's face (chin rest, forehead rest, etc.) and a lens unit for switching the target region of OCT (for example, attachment for anterior segment OCT). ) or any other element or unit may be provided. In some embodiments, the lens unit is configured to be manually inserted and removed between the subject's eye E and the objective lens or collimator lens unit 40 (not shown). In some embodiments, the lens unit is configured to be automatically inserted/removed between the subject's eye E and the objective lens or collimator lens unit 40 (not shown) under the control of the control unit 210, which will be described later.

[OCT unit 100]
FIG. 2 shows an example of the configuration of the OCT unit 100. As shown in FIG. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the eye E to be examined. This optical system divides light from a wavelength sweeping (wavelength scanning) light source into measurement light and reference light, and causes interference between the return light of the measurement light from the subject's eye E and the reference light that has passed through the reference light path. It is an interference optical system that generates an interference light by using an interference optical system and detects the interference light. A detection result (detection signal) of the interference light by the interference optical system is an interference signal indicating the spectrum of the interference light, and is sent to the arithmetic control unit 200 .

The light source unit 101 includes a wavelength sweeping (wavelength scanning) light source capable of sweeping (scanning) the wavelength of emitted light, like a general swept source type ophthalmologic apparatus. A swept-wavelength light source includes a laser light source including a resonator. The light source unit 101 temporally changes the output wavelength in the near-infrared wavelength band invisible to the human eye.

The light source unit 101 can receive a control signal TRG from the arithmetic control unit 200 (control section 210) and start the above wavelength sweeping operation. Thereby, the arithmetic control unit 200 (control section 210) can control the execution timing of the A scan using the control signal TRG.

Light L0 output from the light source unit 101 in response to the control signal TRG from the arithmetic control unit 200 (control section 210) is guided to the polarization controller 103 through the optical fiber 102, and the polarization state is adjusted. The polarization controller 103 adjusts the polarization state of the light L0 guided through the optical fiber 102 by, for example, externally applying stress to the looped optical fiber 102 .

The light L0 whose polarization state has been adjusted by the polarization controller 103 is guided by the optical fiber 104 to the fiber coupler 105 and split into the measurement light LS and the reference light LR.

The reference light LR is guided to the collimator 111 by the optical fiber 110 and converted into a parallel beam, and guided to the optical path length changing section 114 via the optical path length correcting member 112 and the dispersion compensating member 113 . The optical path length correction member 112 acts to match the optical path length of the reference light LR and the optical path length of the measurement light LS. The dispersion compensation member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS.

The optical path length changing unit 114 is movable in the direction of the arrow shown in FIG. 2, and changes the optical path length of the reference light LR. This movement changes the length of the optical path of the reference light LR. This change in the optical path length is used for correction of the optical path length according to the axial length of the eye E to be examined, adjustment of the interference state, and the like. The optical path length changing unit 114 includes, for example, a corner cube and a moving mechanism for moving it. In this case, the corner cube of the optical path length changing unit 114 reverses the traveling direction of the reference light LR that has been collimated by the collimator 111 . The optical path of the reference light LR entering the corner cube and the optical path of the reference light LR emerging from the corner cube are parallel.

The reference light LR that has passed through the optical path length changing unit 114 passes through the dispersion compensating member 113 and the optical path length correcting member 112 , is converted by the collimator 116 from a parallel beam into a focused beam, and enters the optical fiber 117 . The reference light LR incident on the optical fiber 117 is guided to the polarization controller 118 to have its polarization state adjusted, guided to the attenuator 120 via the optical fiber 119 to have its light amount adjusted, and guided to the fiber coupler 122 via the optical fiber 121 . be killed.

On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and made into a parallel light beam by the collimator lens unit 40 . The collimated measurement light LS is deflected by the optical scanner 20 and guided to the reflecting surface of the ellipsoidal mirror 11 . The measurement light LS is reflected by the reflecting surface of the ellipsoidal mirror 11 and enters the eye through the pupil of the eye E to be examined at the position of the eye to be examined. The measurement light LS is scattered (including reflected) at various depth positions of the eye E to be examined. The return light of the measurement light LS including such backscattered light travels in the opposite direction along the same path as the forward path, is guided to the fiber coupler 105 , and reaches the fiber coupler 122 via the optical fiber 128 .

The fiber coupler 122 combines (interferences) the measurement light LS that has entered via the optical fiber 128 and the reference light LR that has entered via the optical fiber 121 to generate interference light. The fiber coupler 122 splits the interference light between the measurement light LS and the reference light LR at a predetermined splitting ratio (for example, 1:1) to generate a pair of interference lights LC. A pair of interference lights LC emitted from the fiber coupler 122 are guided to a detector 125 by optical fibers 123 and 124, respectively.

The detector 125 is, for example, a balanced photodiode that has a pair of photodetectors that respectively detect a pair of interference lights LC and that outputs the difference between the detection results of these. Detector 125 sends the detection result (interference signal) to DAQ (Data Acquisition System) 130 . A clock KC is supplied from the light source unit 101 to the DAQ 130 . The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept (scanned) within a predetermined wavelength range by the wavelength swept light source. The light source unit 101, for example, optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then outputs the clock KC based on the result of detecting these combined lights. Generate. The DAQ 130 samples the detection result of the detector 125 based on the clock KC. The DAQ 130 sends the sampled detection results of the detector 125 to the arithmetic control unit 200 . For example, for each series of wavelength scans (for each A line), the arithmetic control unit 200 performs Fourier transform or the like on the spectral distribution based on the detection results obtained by the detector 125, thereby obtaining a reflection intensity profile for each A line. Form. Furthermore, the arithmetic and control unit 200 forms image data by imaging the reflection intensity profile of each A line.

[Arithmetic control unit 200]
The arithmetic control unit 200 analyzes the detection signal input from the DAQ 130 and forms an OCT image. Arithmetic processing therefor is similar to that of the conventional swept source type OCT apparatus.

Also, the arithmetic control unit 200 controls each part of the optical scanner 20 , the moving mechanism 150 , the OCT unit 100 , and the display device 300 .

The arithmetic control unit 200 controls the OCT unit 100 . Control of the OCT unit 100 includes operation control of the light source unit 101, movement control of the optical path length changing unit 114, operation control of the attenuator 120, operation control of the polarization controllers 103 and 118, operation control of the detector 125, and operation control of the DAQ 130. and so on.

The arithmetic control unit 200 controls the display device 300 . The control of the display device 300 includes display control of an OCT image of the eye to be examined E, information prompting the examiner or the subject to proceed with OCT measurement, and the like.

The arithmetic control unit 200 includes, for example, a processor, a RAM, a ROM, a hard disk drive, a communication interface, etc., like a conventional computer. A computer program for controlling the ophthalmologic apparatus 1 is stored in a storage device such as a hard disk drive. The arithmetic and control unit 200 may include various circuit boards, such as a circuit board for forming OCT images. The arithmetic control unit 200 may also include an operation device (input device) such as a keyboard and mouse, and a display device such as an LCD.

[Control system]
The arithmetic control unit 200 includes a control section 210, an image forming section 220, and a data processing section 230, as shown in FIG. Functions of the arithmetic control unit 200 are implemented by one or more processors. In some embodiments, the functions of the arithmetic control unit 200 are a control processor that implements the functions of the control unit 210, an image forming processor that implements the functions of the image forming unit 220, and a data processing unit 230. It is implemented by a data processor.

FIG. 3 shows a configuration example of the control system of the ophthalmologic apparatus 1. As shown in FIG. In FIG. 3, some of the components included in the ophthalmologic apparatus 1 are omitted.

(control part)
The control unit 210 executes various controls. Control unit 210 includes main control unit 211 and storage unit 212 .

(main controller)
The main controller 211 includes a processor and controls each part of the ophthalmologic apparatus 1 . For example, the main controller 211 controls the optical scanner 20 and the entire optical system (moving mechanism 150). Further, the main control section 211 controls the light source unit 101, the optical path length changing section 114, the attenuator 120, the polarization controllers 103 and 118, the detector 125, the DAQ 130, etc. of the OCT unit 100. FIG.

The main control unit 211 also controls a fixation optical system (not shown) to present a fixation target to the subject's eye E so as to induce fixation to a fixation position set manually or automatically. Is possible.

Further, the main control unit 211 can move the focusing lens (not shown) in the optical axis direction of the interference optical system and change the focus position of the measurement light by controlling the focusing lens (not shown). For example, by moving the focusing lens to the first lens position, the focusing position of the measurement light LS can be arranged at or near the fundus Ef. For example, by moving the focusing lens to the second lens position, the focus position of the measurement light can be arranged at the far point position, and the measurement light LS can be made into a parallel beam. The focus position of the measurement light LS corresponds to the depth position (z position) of the beam waist of the measurement light LS.

The moving mechanism 150, for example, three-dimensionally moves at least part of the optical system 10 (for example, the interference optical system). In a typical example, the moving mechanism 150 includes at least a mechanism for moving the optical system 10 in the x direction (horizontal direction), a mechanism for moving it in the y direction (vertical direction), and a mechanism for moving the optical system 10 in the z direction (depth direction, a mechanism for moving forward and backward). The mechanism for moving in the x-direction includes, for example, an x-stage movable in the x-direction and an x-moving mechanism for moving the x-stage. The mechanism for moving in the y-direction includes, for example, a y-stage movable in the y-direction and a y-moving mechanism for moving the y-stage. The mechanism for moving in the z-direction includes, for example, a z-stage movable in the z-direction and a z-moving mechanism for moving the z-stage. Each moving mechanism includes an actuator such as a pulse motor, and operates under control from the main control unit 211 .

Control over the moving mechanism 150 is used in alignment and tracking. Tracking is to move the apparatus optical system according to the eye movement of the eye E to be examined. Alignment and focus adjustment are performed in advance when tracking is performed. Tracking is a function of maintaining a suitable positional relationship in which alignment and focus are achieved by causing the position of the apparatus optical system to follow the movement of the eyeball. Some embodiments are configured to control movement mechanism 150 to change the optical path length of the reference beam (and thus the optical path length difference between the optical path of the measurement beam and the optical path of the reference beam).

In the case of manual alignment, the user relatively moves the optical system and the subject's eye E by operating a user interface 240, which will be described later, so that the displacement of the subject's eye E with respect to the optical system is cancelled. For example, the main control unit 211 controls the moving mechanism 150 by outputting a control signal corresponding to the operation content of the user interface 240 to the moving mechanism 150 to move the optical system and the subject's eye E relative to each other.

In the case of auto-alignment, the main control unit 211 controls the movement mechanism 150 so that the displacement of the eye E to be examined with respect to the optical system is canceled, thereby relatively moving the optical system and the eye E to be examined. For example, the movement mechanism 150 is controlled so as to cancel the displacement between the image of the subject's eye E acquired by an imaging optical system (not shown) and the reference position of the optical system. In some embodiments, the main controller 211 outputs a control signal such that the optical axis of the optical system substantially coincides with the axis of the eye E to be examined and the distance of the optical system from the eye E to be examined is a predetermined working distance. to the moving mechanism 150 to control the moving mechanism 150 to relatively move the optical system and the eye E to be examined. Here, the working distance is a default value also called a working distance of an objective lens (not shown), and corresponds to the distance between the subject's eye E and the optical system during measurement (during photography) using the optical system.

The main control unit 211 controls OCT measurement by controlling the OCT unit 100 and the like. The main controller 211 can perform a plurality of preliminary operations before performing OCT measurement. Preliminary operations include alignment, focus adjustment, optical path length difference adjustment, and polarization adjustment. A plurality of preliminary operations are performed in a predetermined order. In some embodiments, multiple preliminary operations are performed in the order described above.

Note that the types and order of preliminary operations are not limited to this, and are arbitrary. For example, a preliminary operation (small pupil determination) for determining whether or not the subject's eye E is a small pupil eye can be added to the preliminary operation. Small pupil determination is performed, for example, between coarse focus adjustment and optical path length difference adjustment. In some embodiments, the small pupil determination includes the following series of processing: processing of obtaining a front image (anterior segment image) of the eye E to be examined; processing of identifying an image region corresponding to the pupil; Processing for obtaining the size (diameter, circumference, etc.) of the pupil region obtained; Processing for determining whether or not the eye is a small-pupil eye based on the obtained size (threshold processing); process that controls Some embodiments further include circular or elliptical approximation of the pupil region to determine the pupil size.

Focus adjustment is performed, for example, based on the interference sensitivity of OCT measurement. For example, by monitoring the interference intensity (interference sensitivity) of the interference signal obtained by OCT measurement of the eye E to be examined, the position of the focusing lens that maximizes the interference intensity is determined, and the focusing lens is positioned at that position. Focus adjustment can be performed by moving.

In the optical path length difference adjustment, a predetermined position on the subject's eye E is controlled to be the reference position of the measurement range in the depth direction. This control is performed on the optical path length changing section 114 . Thereby, the optical path length difference between the measurement optical path and the reference optical path is adjusted. By setting the reference position by adjusting the optical path length difference, the OCT measurement can be accurately performed for the desired measurement range in the depth direction simply by changing the wavelength sweep speed.

In the polarization adjustment, the polarization state of the reference light LR is adjusted in order to optimize the interference efficiency between the measurement light LS and the reference light LR.

(storage unit)
The storage unit 212 stores various data. The data stored in the storage unit 212 includes, for example, image data of an OCT image, image data of a fundus image, image data of an anterior segment image, eye information to be examined, and the like. The eye information to be examined includes information about the subject such as patient ID and name, and information about the eye to be examined such as left/right eye identification information.

Further, the storage unit 212 stores timing information 212A in advance. The timing information 212A includes timing information that defines the execution timing of the A-scan. The information defining the execution timing may be information defining intervals between execution timings of A-scans, or may be information defining respective execution timings of a plurality of A-scans. In this embodiment, the timing information 212A is timing information that defines the execution timing of the A-scan so that the intervals of the incident angles of the measurement light LS with respect to the subject's eye are substantially equal. The main control unit 211 can cause the eye E to be examined to undergo an A-scan based on the timing information 212A.

In some embodiments, the timing information 212A includes A-scan timing information relative to the reference timing of the deflection operation of the optical scanner 20 . The reference timing is the timing at which the optical scanner 20 deflects the measurement light LS at a predetermined deflection angle. In this case, the main control unit 211 can cause the subject's eye E to perform an A-scan at the timing specified by the timing information 212A.

The timing information 212A is provided corresponding to the scan mode. That is, the timing information 212A associated with the scan mode is stored in the storage unit 212 in advance. In this case, the timing information 212A includes information that defines the execution timing of the A scan during the scan mode.

The storage unit 212 also stores various programs and data for operating the ophthalmologic apparatus 1 .

The ophthalmologic apparatus 1 is provided with a user interface 240 for receiving operations from the user and presenting information to the user. The control unit 210 can manage interface processing with the user by controlling the user interface 240 .

(Image forming section)
The image forming unit 220 forms an OCT image (image data) of the subject's eye E based on sampling data obtained by sampling the detection signal from the detector 125 with the DAQ 130 . This processing includes processing such as noise removal (noise reduction), filter processing, dispersion compensation, and FFT (Fast Fourier Transform), like conventional swept source type OCT. For other types of OCT devices, the imaging unit 220 performs well-known processing depending on the type.

The image forming unit 220 includes, for example, the aforementioned processor, RAM, ROM, hard disk drive, circuit board, and the like. A storage device such as a hard disk drive pre-stores a computer program that causes the processor to execute the functions described above. In some embodiments, the functions of imaging section 220 are implemented by an imaging processor. In this specification, "image data" and "images" based thereon may be regarded as the same.

(Data processing unit)
The data processing unit 230 processes data obtained by photographing the eye E to be examined or by OCT measurement.

The data processing section 230 performs various image processing and analysis processing on the image formed by the image forming section 220 . For example, the data processing unit 230 executes various correction processes such as image luminance correction. In addition, the data processing unit 230 can perform various image processing and analysis processing on an image (a fundus image, an anterior segment image, etc.) obtained by an imaging optical system (not shown).

For example, the data processing unit 230 executes known image processing such as interpolation processing for interpolating pixels between tomographic images to form image data of a three-dimensional image of the fundus oculi Ef. Note that image data of a three-dimensional image means image data in which pixel positions are defined by a three-dimensional coordinate system. Image data of a three-dimensional image includes image data composed of voxels arranged three-dimensionally. This image data is called volume data or voxel data. When displaying an image based on volume data, the data processing unit 230 performs rendering processing (volume rendering, MIP (Maximum Intensity Projection: maximum intensity projection), etc.) on this volume data so that it can be viewed from a specific line-of-sight direction. Image data of a pseudo three-dimensional image is formed. This pseudo three-dimensional image is displayed on the user interface 240 (display unit 240A).

Stack data of a plurality of tomographic images can also be formed as image data of a three-dimensional image. Stacked data is image data obtained by three-dimensionally arranging a plurality of tomographic images obtained along a plurality of scan lines based on the positional relationship of the scan lines. That is, stack data is image data obtained by expressing a plurality of tomographic images, which were originally defined by individual two-dimensional coordinate systems, by one three-dimensional coordinate system (that is, embedding them in one three-dimensional space). be.

The data processing unit 230 performs various renderings on the acquired three-dimensional data set (volume data, stack data, etc.) to obtain a B-mode image (longitudinal cross-sectional image, axial cross-sectional image) at an arbitrary cross section, C-mode images (cross-sectional images, horizontal cross-sectional images), projection images, shadowgrams, etc. can be formed. An arbitrary cross-sectional image, such as a B-mode image or a C-mode image, is formed by selecting pixels (pixels, voxels) on a specified cross-section from a three-dimensional data set. A projection image is formed by projecting a three-dimensional data set in a predetermined direction (z direction, depth direction, axial direction). A shadowgram is formed by projecting a portion of the three-dimensional data set (for example, partial data corresponding to a specific layer) in a predetermined direction. An image such as a C-mode image, a projection image, or a shadowgram whose viewpoint is the front side of the subject's eye is called an en-face image.

The data processing unit 230 generates a B-mode image or a frontal image (blood vessel-enhanced image, angiogram) in which retinal blood vessels and choroidal blood vessels are emphasized, based on data (for example, B-scan image data) collected in time series by OCT. can be constructed. For example, time-series OCT data can be collected by repeatedly scanning substantially the same portion of the eye E to be examined.

In some embodiments, the data processing unit 230 compares time-series B-scan images obtained by B-scans of substantially the same site, and converts the pixel values of the portions where the signal intensity changes to the pixel values corresponding to the changes. An enhanced image in which the changed portion is emphasized is constructed by the conversion. Furthermore, the data processing unit 230 extracts information for a predetermined thickness in a desired region from the constructed multiple enhanced images and constructs an en-face image to form an OCTA image.

Images generated by the data processing unit 230 (eg, three-dimensional images, B-mode images, C-mode images, projection images, shadowgrams, OCTA images) are also included in the OCT images.

Further, the data processing unit 230 analyzes the detection result of the interference light obtained by the OCT measurement and determines the focus state of the measurement light LS in the focus adjustment control. For example, the main control unit 211 performs repetitive OCT measurements while controlling a focus driving unit that drives the focus lens according to a predetermined algorithm. The data processing unit 230 calculates a predetermined evaluation value regarding the image quality of the OCT image by analyzing the detection results of the interfering light LC repeatedly obtained by the OCT measurement. The data processing unit 230 determines whether or not the calculated evaluation value is equal to or less than the threshold. In some embodiments, focus adjustment continues until the calculated evaluation value is equal to or less than the threshold. That is, when the evaluation value is equal to or less than the threshold value, it is determined that the focus state of the measurement light LS is appropriate, and focus adjustment is continued until it is determined that the focus state of the measurement light LS is appropriate.

In some embodiments, the main control unit 211 performs repetitive OCT measurements as described above to acquire an interference signal, and monitors the intensity of the sequentially acquired interference signal (interference intensity, interference sensitivity). do. Furthermore, by moving the focusing lens while performing this monitoring process, a position of the focusing lens that maximizes the interference intensity is searched for. Such focus adjustment allows the focusing lens to be brought to a position where the interference intensity is optimized.

The data processing unit 230 also analyzes the detection result of the interference light obtained by the OCT measurement, and determines the polarization state of at least one of the measurement light LS and the reference light LR. For example, the main controller 211 performs repetitive OCT measurements while controlling at least one of the polarization controllers 103 and 118 according to a predetermined algorithm. In some embodiments, the main controller 211 controls the attenuator 120 to change the amount of attenuation of the reference light LR. The data processing unit 230 calculates a predetermined evaluation value regarding the image quality of the OCT image by analyzing the detection results of the interfering light LC repeatedly obtained by the OCT measurement. The data processing unit 230 determines whether or not the calculated evaluation value is equal to or less than the threshold. This threshold is preset. Polarization adjustment continues until the calculated evaluation value becomes equal to or less than the threshold. That is, when the evaluation value is equal to or less than the threshold, it is determined that the polarization state of the measurement light LS is proper, and the polarization adjustment is continued until it is determined that the polarization state of the measurement light LS is proper.

In some embodiments, the main controller 211 can also monitor interference strength during polarization adjustment.

Further, the data processing unit 230 performs predetermined analysis processing on the detection result of the interference light obtained by the OCT measurement or the OCT image formed based on the detection result. Predetermined analysis processing includes identification of a predetermined site (tissue, lesion) in the eye to be examined E; calculation of the distance (interlayer distance), area, angle, ratio, and density between the designated sites; designated calculation formula specification of the shape of a predetermined site; calculation of these statistical values; calculation of the distribution of the measured values and statistical values; and image processing based on these analysis processing results. Predetermined tissues include blood vessels, optic disc, fovea fovea, macula, and the like. Predetermined lesions include vitiligo, hemorrhage, and the like.

The data processing unit 230 that functions as described above includes, for example, the aforementioned processor, RAM, ROM, hard disk drive, circuit board, and the like. A storage device such as a hard disk drive pre-stores a computer program that causes the processor to execute the functions described above. In some embodiments, the functionality of data processing unit 230 is implemented by a data processing processor.

(user interface)
The user interface 240 includes a display section 240A and an operation section 240B. The display unit 240A includes the display device of the arithmetic control unit 200 and the display device 300 described above. The operation section 240B includes the operation device of the arithmetic control unit 200 described above. The operation unit 240B may include various buttons and keys provided on the housing of the ophthalmologic apparatus 1 or on the outside. For example, if the ophthalmologic apparatus 1 has a housing similar to that of a conventional fundus camera, the operation section 240B may include a joystick, an operation panel, etc. provided in this housing. Moreover, the display unit 240A may include various display devices such as a touch panel provided in the housing of the ophthalmologic apparatus 1 .

Note that the display unit 240A and the operation unit 240B do not need to be configured as individual devices. For example, it is possible to use a device such as a touch panel in which a display function and an operation function are integrated. In that case, the operation unit 240B is configured including this touch panel and a computer program. The content of the operation performed on the operation unit 240B is input to the control unit 210 as an electric signal. Further, operations and information input may be performed using a graphical user interface (GUI) displayed on the display unit 240A and the operation unit 240B.

FIG. 4 is a diagram for explaining the relationship between the deflection angle of the measurement light of the optical scanner according to the comparative example of the embodiment and the incident angle of the measurement light at the position of the subject's eye.

The optical scanner SC deflects the light LL from the light source and guides it to the reflecting surface of the ellipsoidal mirror EL. The light LL deflected by the optical scanner SC is reflected by the reflecting surface of the ellipsoidal mirror EL and guided to the eye E to be examined. As shown in FIG. 4, even when the light LL is deflected at substantially equal intervals of deflection angles, the incident angle of the light L1 deflected at the first deflection angle and the incident angle of the light L2 deflected at the second deflection angle are The interval between the incident angle and the interval between the incident angle of the light L2 deflected by the second deflection angle and the incident angle of the light L3 deflected by the third deflection angle become non-uniform. That is, there is a non-linear relationship between the deflection angle (interval) by the optical scanner and the incident angle (interval) at the position of the eye to be examined.

In the embodiment, by correcting the distortion of the incident angles (intervals) based on such a nonlinear relationship, it is possible to prevent the deterioration of the measurement accuracy due to the deviation of the scanning position.

5 to 7 are explanatory diagrams of operations of the ophthalmologic apparatus 1 according to the first embodiment. FIG. 5 is a diagram for explaining a main part of the configuration of the ophthalmologic apparatus 1 according to the first embodiment. In FIG. 5, parts similar to those in FIG. 2 or FIG. FIG. 6 shows an operation explanatory diagram of the control unit 210 according to the first embodiment. In FIG. 6, the horizontal axis represents the time corresponding to the A-scan execution timing (data set acquisition timing), and the vertical axis represents the incident angle of the measurement light LS at the position of the subject's eye. In FIG. 6, the same parts as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. FIG. 7 schematically shows a tomographic image of the fundus Ef of the eye E to be examined. Note that in FIG. 7, the number of A-scans in the tomographic images IMG0 and IMG1 is an example, and is not limited to that number.

The optical scanner 20 includes, for example, a mirror that reflects the measurement light LS, and deflects the measurement light LS within a predetermined deflection angle range by swinging the mirror reciprocally in a swing direction corresponding to a predetermined deflection direction. . For example, the incident angle range is a range between an incident start angle rs (first incident angle) and an incident end angle re (second incident angle), as shown in FIG. That is, in the incident angle range of the measurement light LS deflected by the optical scanner 20 at the position of the subject's eye, as shown in FIG. It includes a linear operating range in which the operation is linear, and a non-linear operating range in which the change in the incident angle does not operate linearly with respect to the change in the data set acquisition timing. The nonlinear operating range includes a start angle of incidence rs and an end angle of incidence re.

A tomographic image IMG0 as shown in FIG. 7 is obtained from a data set group in the A-scan direction obtained by the measurement light LS incident on the subject's eye E in the incident angle range shown in FIG. In the tomographic image IMG0 shown in FIG. 7, the intervals between A-scans based on the measurement light incident on the subject's eye are non-uniform. Therefore, in practice, distortion due to the nonlinearity described above occurs in a tomographic image formed using a group of acquired data sets.

On the other hand, as shown in FIG. 5, the main control unit 211 outputs the control signal TRG to the light source unit 101 at the execution timing specified by the timing information 212A based on the reference timing of the deflection operation of the optical scanner 20. is output to control the execution timing of the A scan. In some embodiments, the main controller 211 specifies the reference timing of the deflection operation of the optical scanner 20 by outputting a control signal COM to the optical scanner 20 .

As a result, the main control unit 211 outputs the control signal TRG to the light source unit 101, whereby the wavelength sweeping operation is started in synchronization with the output timing of the control signal TRG, and the interference light LC is generated in the DAQ 130 in synchronization with the clock KC. A detection result is obtained. That is, the main control unit 211 can acquire data of the subject's eye E at scanning positions scanned at approximately the same scanning angle by controlling the execution timing of the A scan using the control signal TRG.

For example, as shown in FIG. 6, the timing information 212A includes A-scan execution timings t1, t2, and t3 so that the intervals between the incident angles of the measuring light LS at the position of the subject's eye are substantially equal over the entire incident angle range. , . . . , tN (N is an integer equal to or greater than 2) is stored in the storage unit 212 in advance.

In some embodiments, the timing information 212A is identified in advance from the operating characteristics of the optical scanner 20 and the known shape of the reflecting surface of the ellipsoidal mirror 11 and stored in the storage unit 212 . For example, the timing information 212A is saved before the shipping process, inspection process, or OCT measurement. For example, the main control unit 211 controls the deflection operation of the optical scanner 20 by outputting to the optical scanner 20 a control signal containing information representing a control waveform that defines the deflection operation of a mirror that deflects the measurement light LS. do. Further, the main control unit 211 outputs a control signal COM to the optical scanner 20, receives a response signal RES including the operating state such as the deflection angle of the optical scanner 20, and uses the received response signal RES to control the optical scanner 20. is monitored to determine the timing information 212A. Main control unit 211 stores specified timing information 212A in storage unit 212 .

As described above, according to the first embodiment, A-scan data can be acquired based on the measurement light LS deflected by the optical scanner 20 at deflection angles that are substantially equally spaced over the entire deflection angle range. A tomographic image IMG1 of the fundus oculi Ef as shown in FIG. 7 is obtained. The tomographic image IMG1 shown in FIG. 7 is formed from a data set group acquired by the measurement light LS incident on the subject's eye E at substantially equal incident angles in the deflection angle range, regardless of the nonlinear operation of the optical scanner 20. be done. Therefore, it is possible to improve the measurement accuracy without causing distortion due to the nonlinearity in the formed tomographic image.

The optical systems on the path from the interference optical system included in the OCT unit 100 to the ellipsoidal mirror 11, or these optical systems and the image forming unit 220 are examples of the "acquisition unit" according to the embodiment.

[motion]
The operation of the ophthalmologic apparatus 1 according to the first embodiment will be described.

FIG. 8 shows an operation example of the ophthalmologic apparatus 1 according to the first embodiment. FIG. 8 shows a flowchart of an operation example of the ophthalmologic apparatus 1 according to the first embodiment. A computer program for realizing the processing shown in FIG. 8 is stored in the storage unit 212 . The main control unit 211 executes the processing shown in FIG. 8 by operating according to this computer program.

(S1: Specify scan mode)
The main control unit 211 accepts a scan mode designation by the user.

The user can specify the scan mode or the operation mode by operating the operation unit 240B. When the user designates a scan mode by operating the operation unit 240B, the main control unit 211 analyzes the operation information from the operation unit 240B and identifies the designated scan mode. When the user designates an operation mode by operating the operation unit 240B, the main control unit 211 analyzes the operation information and identifies the scan mode previously designated in the designated operation mode.

(S2: Set timing information)
The main control unit 211 identifies the timing information 212A stored in the storage unit 212 corresponding to the scan mode designated in step S1, and sets it as the timing information to be referred to during the scan.

For example, the main control unit 211 includes information representing a control waveform that defines the deflection operation of the mirror that deflects the measurement light LS with respect to the optical scanner 20 at an arbitrary timing between step S2 and step S7 described later. Output a control signal. In each step from step S4 to step S7, the main control unit 211 may output a control signal including information representing predetermined control waveforms different from each other, or may output information representing the same predetermined control waveform. You may output the control signal containing.

(S3: Alignment)
Next, the main controller 211 executes alignment.

That is, the main controller 211 controls an alignment optical system (not shown) to project an alignment index onto the eye E to be inspected. At this time, the fixation target is also projected onto the eye E to be examined. The main control unit 211 controls the moving mechanism 150 based on the amount of movement of the optical system specified based on the received light image acquired using the photographing optical system (not shown), and moves the optical system to the subject's eye E. Relatively move by the amount of movement. The main control unit 211 causes this process to be repeatedly executed.

(S4: Acquiring a tomographic image for adjustment)
The main control unit 211 displays, for example, a fixation target for OCT measurement at a predetermined position.

Subsequently, the main control unit 211 controls the OCT unit 100 to perform OCT provisional measurement and acquire an adjustment tomographic image for adjusting the reference position of the measurement range in the depth direction. Specifically, the main control unit 211 controls the light scanner 20 to deflect the measuring light LS generated based on the light L0 emitted from the light source unit 101, and the deflected measuring light LS A predetermined site (for example, the fundus) of the eye E to be examined is scanned. A detection result of the interference light obtained by scanning the measurement light LS is sampled in synchronization with the clock KC and then sent to the image forming section 220 . The image forming unit 220 forms a tomographic image (OCT image) of the subject's eye E from the obtained interference signal.

(S5: Adjust the reference position in the depth direction)
Subsequently, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction).

For example, the main control unit 211 causes the data processing unit 230 to specify a predetermined site (for example, the sclera) in the tomographic image obtained in step S4, and the position of the specified predetermined site in the depth direction. A position separated by a predetermined distance is set as a reference position of the measurement range. Also, a predetermined position determined in advance so that the optical path lengths of the measurement light LS and the reference light LR substantially match may be set as the reference position of the measurement range.

(S6: focus adjustment, polarization adjustment)
Next, the main controller 211 executes focus adjustment control and polarization adjustment control.

For example, the main control unit 211 controls the focus driving unit (not shown) to move the focus lens by a predetermined distance, and then controls the OCT unit 100 to perform OCT measurement. As described above, the main control unit 211 causes the data processing unit 230 to determine the focus state of the measurement light LS based on the detection result of the interference light obtained by the OCT measurement. When it is determined that the focus state of the measurement light LS is not appropriate based on the determination result by the data processing unit 230, the main control unit 211 controls the focus driving unit again to determine that the focus state is appropriate. repeat until

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

(S7: Acquire interference signal)
Subsequently, the main control unit 211 outputs the control signal TRG to the light source unit 101 at the execution timing specified based on the timing information set in step S2 with reference to the reference timing of the deflection operation of the optical scanner 20. OCT measurement (at least A scan) is performed on the fundus oculi Ef. A detection result of interference light obtained by the OCT measurement is sampled by the DAQ 130 and stored as an interference signal in the storage unit 212 or the like.

(S8: Form a tomogram)
Next, the main control unit 211 causes the image forming unit 220 to form a data set group of A-scan image data of the fundus oculi Ef based on the interference signal acquired in step S7. The main control unit 211 can cause the display unit 240A to display a B-scan image (the tomographic image IMG1 in FIG. 7) based on the generated data set group of A-scan image data.

With this, the operation of the ophthalmologic apparatus 1 is completed (end).

[Second embodiment]
In the first embodiment, the case where the ophthalmologic apparatus 1 performs OCT measurement on the subject's eye E by feedforward control has been described, but the configuration of the ophthalmologic apparatus according to the embodiment is not limited to this. The ophthalmologic apparatus 1 according to the second embodiment performs OCT measurement on the subject's eye E under feedback control.

The ophthalmologic apparatus 1 according to the second embodiment will be described below, focusing on differences from the first embodiment.

The configuration of the ophthalmologic apparatus 1 according to the second embodiment is substantially the same as the configuration of the ophthalmologic apparatus 1 according to the first embodiment. The ophthalmic apparatus 1 according to the second embodiment differs from the ophthalmic apparatus 1 according to the first embodiment in that OCT measurement is performed according to the deflection operation state of the optical scanner 20 without referring to the timing information 212A. be.

FIG. 9 shows an operation explanatory diagram of the control unit 210 according to the second embodiment. In FIG. 9, parts similar to those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the second embodiment, the ophthalmologic apparatus 1 performs OCT measurement (at least A scan) according to the deflection angle of the optical scanner 20 . Specifically, the main control unit 211 acquires motion information representing the deflection angle from the optical scanner 20, and determines whether or not the deflection angle of the mirror is a predetermined deflection angle based on the acquired motion information. , the A-scan is performed by controlling the OCT unit 100 when the deflection angle is determined to be the predetermined deflection angle. The predetermined deflection angle is predetermined.

That is, the main control unit 211 receives the response signal RES including the operation information by outputting the control signal COM to the optical scanner 20, and determines the deflection angle of the mirror from the operation information included in the received response signal RES. Identify. The main control unit 211 determines whether or not the deflection angle of the mirror is a predetermined deflection angle based on the acquired operation information. A-scan is executed by outputting a control signal TRG to .

When the main control unit 211 outputs the control signal TRG to the light source unit 101, the wavelength sweeping operation is started in synchronization with the output timing of the control signal TRG, and the detection result of the interference light LC is obtained in the DAQ 130 in synchronization with the clock KC. is obtained.

[motion]
The operation of the ophthalmologic apparatus 1 according to the second embodiment will be described.

FIG. 10 shows an operation example of the ophthalmologic apparatus 1 according to the embodiment. FIG. 10 shows a flowchart of an operation example of the ophthalmologic apparatus 1 according to the second embodiment. A computer program for realizing the processing shown in FIG. 10 is stored in the storage unit 212 . The main control unit 211 executes the processing shown in FIG. 10 by operating according to this computer program.

(S11: Specify scan mode)
The main control unit 211 accepts the user's designation of the scan mode, as in step S1.

(S12: Alignment)
Next, the main controller 211 performs alignment as in step S3.

(S13: Acquiring a tomographic image for adjustment)
The main control unit 211 displays a fixation target for OCT measurement at a predetermined position on the LCD 39 as in step S4. Subsequently, the main control unit 211 controls the OCT unit 100 to perform OCT provisional measurement and acquire an adjustment tomographic image for adjusting the reference position of the measurement range in the depth direction.

(S14: Adjust the reference position in the depth direction)
Subsequently, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction) as in step S5.

(S15: focus adjustment, polarization adjustment)
Next, the main control unit 211 executes focus adjustment control and polarization adjustment control as in step S6.

(S16: Acquire interference signal)
Subsequently, the main control unit 211 outputs a control signal TRG to the light source unit 101 according to the deflection angle of the optical scanner 20, thereby controlling the OCT unit 100 at the execution timing according to the deflection angle. OCT measurement (at least A scan) is performed on the fundus oculi Ef of the eye E to be examined.

Specifically, the main controller 211 acquires the deflection angle of the optical scanner 20 from the operation information included in the response signal RES periodically received from the optical scanner 20 . Each time the deflection angle is acquired, the main control unit 211 determines whether the deflection angle of the mirror is a predetermined deflection angle. By outputting the control signal TRG to 101, the A scan is executed. Such A-scan execution control by the control signal TRG is repeated within a predetermined scan range.

A detection result of interference light obtained by the OCT measurement is sampled by the DAQ 130 and stored as an interference signal in the storage unit 212 or the like.

(S17: Form a tomogram)
Next, the main control unit 211 causes the image forming unit 220 to form a data set group of A-scan image data of the fundus oculi Ef based on the interference signal acquired in step S16, as in step S8.

With this, the operation of the ophthalmologic apparatus 1 is completed (end).

[Third embodiment]
In the first embodiment or the second embodiment, the case where the A-scan is executed so that the fundus oculi Ef is scanned at substantially equal deflection angles has been described. It is not limited to this.

The ophthalmologic apparatus 1 according to the third embodiment is configured so that the anterior segment Ea is mainly scanned at substantially equal scanning intervals (so that the intervals between the projection positions of the measurement light LS in the anterior segment Ea are substantially equal). ) Perform an A-scan.

For example, the configuration of the ophthalmologic apparatus 1 according to the third embodiment is substantially the same as the configuration of the ophthalmologic apparatus 1 according to the first or second embodiment. In this case, in the third embodiment, a front lens is arranged between the subject's eye E and the collimator lens unit 40 in the ophthalmologic apparatus 1 according to the first embodiment or the second embodiment. As a result, the anterior ocular segment Ea of the eye E to be examined is irradiated with the collimated measuring light LS.

For example, in the third embodiment, the timing information 212A is stored so that A-scans are performed at substantially equal scanning intervals. When the front lens is placed at the predetermined position, the main control unit 211 executes OCT measurement for the anterior segment Ea based on the timing information 212A, thereby scanning the anterior segment Ea at substantially equal scanning intervals. An A-scan can be performed.

For example, in the third embodiment, when the front lens is arranged at a predetermined position, the main control unit 211 causes the deflection angle of the optical scanner 20 to be deflected by a predetermined deflection angle which is predetermined so that the scanning intervals are substantially equal. Determine whether it is an angle. The main control unit 211 executes OCT measurement for the anterior segment Ea when the deflection angle is determined to be the predetermined deflection angle. As a result, A-scans can be performed on the anterior segment Ea at substantially equal scanning intervals.

In some embodiments, the operating modes of the ophthalmic device 1 include a fundus measurement mode and an anterior segment measurement mode. For example, in the ophthalmologic apparatus 1 according to the first embodiment, the timing information 212A includes timing information for the fundus measurement mode and timing information for the anterior segment measurement mode. In the fundus measurement mode, the A-scan is executed so as to scan at approximately the same scanning angle (deflection angle) based on the timing information for the fundus measurement mode. Based on the information, A-scans are performed to scan at approximately equal scan intervals.

For example, the ophthalmologic apparatus 1 according to the second embodiment is configured to be able to determine whether or not the deflection angle of the optical scanner 20 is a predetermined deflection angle for the fundus measurement mode. The predetermined deflection angle for the fundus measurement mode is a deflection angle that is set to scan at approximately equal scan angles (deflection angles). Accordingly, in the fundus measurement mode, when the deflection angle of the optical scanner 20 is determined to be the predetermined deflection angle for the fundus measurement mode, the A scan is performed so as to scan at substantially the same scanning angle (deflection angle). be. Further, the ophthalmologic apparatus 1 according to the second embodiment is configured to be able to determine whether or not the deflection angle of the optical scanner 20 is the predetermined deflection angle for the anterior segment measurement mode. The predetermined deflection angle for the anterior segment measurement mode is a deflection angle set to scan at approximately equal scan intervals. Accordingly, in the anterior eye measurement mode, when the deflection angle of the optical scanner 20 is determined to be the predetermined deflection angle for the anterior eye measurement mode, the A scan is performed so as to scan at substantially equal scanning intervals. be.

[Fourth embodiment]
In the first to third embodiments described above, the optical system 10 includes the optical scanner 20 and the ellipsoidal mirror 11, but the configuration of the ophthalmologic apparatus according to the embodiment is limited to this. isn't it. In the ophthalmologic apparatus according to the embodiment, the optical system may include a plurality of ellipsoidal mirrors (concave mirrors). The configuration of the ophthalmologic apparatus according to the fourth embodiment will be described below, focusing on differences from the configuration of the ophthalmologic apparatus 1 according to the first embodiment.

FIG. 11 shows a configuration example of an ophthalmologic apparatus according to the third embodiment. In FIG. 11, the same parts as in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

The configuration of the ophthalmologic apparatus 1a according to the fourth embodiment differs from the configuration of the ophthalmologic apparatus 1 according to the first embodiment shown in FIG. 1 in that an optical system 10a is provided instead of the optical system 10. . The optical system 10a includes optical scanners 20A and 20B and ellipsoidal mirrors 11A and 11B. The optical scanner 20A, for example, deflects the measurement light LS so as to scan the imaging region in a vertical direction orthogonal to the optical path (optical axis) of the measurement light LS. The optical scanner 20B deflects the measurement light LS deflected by the optical scanner 20A, for example, so as to scan the imaging region in the vertical direction orthogonal to the optical path (optical axis) of the measurement light LS. In some embodiments, the optical system 10a includes a concave mirror having a concave reflecting surface instead of at least one of the ellipsoidal mirrors 11A and 11B. In some embodiments, the reflective surface of the concave mirror is formed to be a freeform surface.

The ellipsoidal mirror 11A, like the ellipsoidal mirror 11, has two optically conjugate focal points (a third focal point and a fourth focal point). The ellipsoidal mirror 11B, like the ellipsoidal mirror 11, has two optically conjugate focal points (fifth and sixth focal points). The optical scanner 20A (deflecting surface of the optical scanner 20A) is arranged at or near the third focal point of the ellipsoidal mirror 11A, or at a position optically conjugate with the third focal point (a conjugate position of the third focal point) or near the same. be. The optical scanner 20B (deflecting surface of the optical scanner 20B) is arranged at or near the fourth focal point of the ellipsoidal mirror 11A, or at or near a position optically conjugate with the fourth focal point (a conjugate position of the fourth focal point). be. In addition, the optical scanner 20B (the deflection surface of the optical scanner 20B) is positioned at or near the fifth focal point of the ellipsoidal mirror 11B, or at a position optically conjugate with the fifth focal point (conjugate position of the fifth focal point) or near the same. placed. The position of the eye to be examined where the eye to be examined E (pupil) is arranged is the sixth focal point of the ellipsoidal mirror 11B or its vicinity, or a position optically conjugated with the sixth focal point (conjugate position of the sixth focal point) or its vicinity. placed.

The ophthalmologic apparatus 1a having such a configuration can form an OCT image of the subject's eye E according to the flow shown in FIG. 8 or 10, as in the first embodiment.

In the above embodiment, the optical scanner 20 has been described as a galvanometer scanner, but the configuration according to the embodiment is not limited to this. For example, the optical scanner 20 may consist of a resonant mirror or a polygon mirror.

[effect]
An ophthalmologic apparatus according to an embodiment and a control method thereof will be described.

The ophthalmologic apparatus (1, 1a) according to some embodiments includes an acquisition unit (optical systems in the path from the interference optical system included in the OCT unit 100 to the ellipsoidal mirror 11, or these optical systems and the image forming unit 220). and a controller (210, main controller 211). The acquisition unit includes concave mirrors (ellipsoidal mirrors 11, 11A, 11B) and light scanners (20, 20A, 20B) that deflect the measurement light (LS) and guide it to the reflecting surfaces of the concave mirrors. Data (OCT data) of the eye to be inspected is obtained by executing an A scan on the eye to be inspected (E) placed at the position of the eye to be inspected or its conjugate position using optical coherence tomography using the measured light. The control unit causes the acquisition unit to perform an A-scan according to the deflection operation state of the optical scanner.

With such a configuration, the A-scan can be executed when the deflection operation state of the optical scanner is in a desired state. It is possible to acquire data at a desired scanning position on the measurement site by taking into consideration the change characteristics of the incident angle of the measurement light at the position of the eye to be inspected due to the shape of the reflecting surface. As a result, it is possible to provide an ophthalmologic apparatus capable of performing wide-angle and highly accurate measurement using a concave mirror.

In some embodiments, the concave mirror is an ellipsoidal mirror (11, 11A, 11B) and the light scanner is positioned at or near the first focus (third focus, fifth focus) of the ellipsoidal mirror, or at the first Placed at or near the conjugate position of the focal point, and the position of the eye to be examined is placed at or near the second focal point (fourth focus, sixth focus) of the ellipsoidal mirror, or at or near the conjugate position of the second focal point .

With such a configuration, it is possible to obtain data at a desired scanning position on the measurement site in consideration of the reflection from the reflecting surface of the ellipsoidal mirror. Accurate measurement becomes possible.

Some embodiments include a storage unit (212) that pre-stores A-scan timing information (212A), and the control unit causes the acquisition unit to perform an A-scan based on the timing information.

According to such a configuration, the A-scan is performed at a desired timing by simple feedforward control according to the change characteristic of the deflection angle of the measurement light by the optical scanner and the change characteristic of the incident angle of the measurement light at the position of the eye to be examined. it can be executed.

In some embodiments, the timing information includes A-scan timing information based on the reference timing of the deflection operation of the optical scanner, and the control unit causes the acquisition unit to perform the A-scan at the timing specified by the timing information. Let

According to such a configuration, it is possible to execute the A-scan at desired timing by simple feedforward control based on the reference timing of the deflection operation of the optical scanner.

In some embodiments, the controller causes the acquisition unit to perform an A-scan according to the deflection angle of the optical scanner.

According to such a configuration, since the A-scan is executed according to the deflection angle of the optical scanner, it is possible to execute the A-scan with simple feedback control.

In some embodiments, the controller acquires motion information representing the deflection angle of the optical scanner, determines whether the deflection angle is a predetermined deflection angle based on the acquired motion information, and determines the deflection angle is the predetermined deflection angle, the acquisition unit is caused to perform an A-scan.

According to such a configuration, since the A-scan is executed when the deflection angle of the optical scanner is the desired deflection angle, it is possible to acquire data at the desired scanning position.

In some embodiments, the control unit causes the acquisition unit to perform an A-scan so that the intervals between the angles of incidence of the measurement light beams at the positions of the subject's eyes are substantially equal.

According to such a configuration, it is possible to acquire data at scanning positions scanned at approximately equal intervals of incident angles, so that data at approximately uniform positions can be acquired in a portion having a curved shape such as the fundus of the eye. be able to

In some embodiments, the control unit causes the acquisition unit to perform an A-scan so that the intervals between the projection positions of the measurement light on the subject's eye are substantially equal.

With such a configuration, it is possible to acquire data at scanning positions scanned at approximately equal scanning intervals, so data at approximately uniform positions in a region scanned with a parallel light beam, such as the anterior segment of the eye, can be acquired. can be obtained.

Some embodiments include an ophthalmic device ( 1, 1a). A control method for an ophthalmologic apparatus performs an A-scan on an eye to be examined (E) placed at a position of the eye to be examined or its conjugate position using optical coherence tomography using measurement light reflected by a reflective surface. It includes an acquisition step of acquiring optometric data (OCT data) and a control step of executing an A-scan according to the deflection operation state of the optical scanner.

According to this method, the A-scan can be executed when the deflection operation state of the optical scanner is in the desired state. It is possible to acquire data at a desired scanning position on the measurement site by taking into consideration the change characteristics of the incident angle of the measurement light at the position of the eye to be inspected due to the shape of the reflecting surface. As a result, it becomes possible to measure with a wider angle and with higher accuracy using a concave mirror.

In some embodiments, the concave mirror is an ellipsoidal mirror (11, 11A, 11B) and the light scanner is positioned at or near the first focus (third focus, fifth focus) of the ellipsoidal mirror, or at the first Placed at or near the conjugate position of the focal point, and the position of the eye to be examined is placed at or near the second focal point (fourth focus, sixth focus) of the ellipsoidal mirror, or at or near the conjugate position of the second focal point .

According to such a method, it is possible to obtain data at a desired scanning position on the measurement site in consideration of the reflection from the reflecting surface of the ellipsoidal mirror. Accurate measurement becomes possible.

In some embodiments, the control step causes the A-scan to be performed based on pre-stored A-scan timing information (212A).

According to such a method, the A-scan is performed at a desired timing by simple feedforward control according to the variation characteristics of the deflection angle of the measurement light by the optical scanner and the variation characteristics of the incident angle of the measurement light at the position of the eye to be inspected. it can be executed.

In some embodiments, the timing information includes A-scan timing information relative to the reference timing of the deflection operation of the optical scanner, and the controlling step causes the A-scan to be performed at the timing specified by the timing information.

According to such a method, it is possible to execute the A-scan at desired timing by simple feedforward control based on the reference timing of the deflection operation of the optical scanner.

In some embodiments, the controlling step causes an A-scan to be performed depending on the deflection angle of the optical scanner.

According to this method, the A-scan is executed according to the deflection angle of the optical scanner, so it is possible to execute the A-scan with simple feedback control.

In some embodiments, the control step includes a motion information acquiring step of acquiring motion information representing the deflection angle of the optical scanner, and determining whether the deflection angle is a predetermined deflection angle based on the acquired motion information. and an executing step of executing an A-scan when the deflection angle is determined to be the predetermined deflection angle in the determining step.

According to this method, since the A-scan is executed when the deflection angle of the optical scanner is the desired deflection angle, it is possible to acquire data at the desired scanning position.

In some embodiments, the control step causes the A-scan to be performed such that the intervals between the angles of incidence of the measurement light beams at the eye positions to be examined are substantially equal.

According to such a method, it is possible to acquire data at scanning positions scanned at approximately equal intervals of incident angles, so that data at approximately uniform positions can be acquired in a region with a curved shape such as the fundus of the eye. be able to

In some embodiments, the control step causes the A-scan to be performed such that the intervals between the projection positions of the measurement light on the subject's eye are substantially equal.

According to this method, it is possible to obtain data at scanning positions scanned at substantially equal scanning intervals, so data at substantially uniform positions in a region scanned with a parallel light beam, such as the anterior segment of the eye, can be obtained. can be obtained.

<Others>
In the above embodiment, the case of using swept source type OCT has been described, but spectral domain type OCT may also be used. In this case, the light source unit 101 uses a low coherence light source (e.g., SLD light source) instead of the swept-wavelength light source, and the interference optical system uses a spectrometer and an imaging device (e.g., CCD) instead of the detector 125. be done.

The embodiment shown above is merely an example for carrying out the present invention. A person who intends to implement this invention can make arbitrary modifications, omissions, additions, etc. within the scope of the gist of this invention.

Although the ophthalmologic apparatus capable of performing OCT has been described in the above embodiment, the configuration according to the above embodiment is not limited to this. The above-described embodiments are also applicable to ophthalmic equipment including a scanning laser ophthalmoscope (SLO) using an ellipsoidal mirror or a concave mirror. Here, the SLO scans the subject's eye (for example, fundus) with light from a light source, and forms an image by detecting the returned light with a light receiving device. That is, the ophthalmologic apparatus includes an acquisition section and a control section. The acquisition unit includes a concave mirror and a light scanner that deflects the light from the light source within a predetermined deflection angle range and guides it to the reflecting surface of the concave mirror, and arranges the light reflected by the reflecting surface at the position of the subject's eye or its conjugate position. The subject's eye is irradiated with the light, and data of the subject's eye is acquired based on the returned light. The control unit acquires data of the subject's eye by causing the acquisition unit to irradiate the light from the light source according to the deflection operation state of the optical scanner.

In some embodiments, a program is provided for causing a computer to execute the above-described method for controlling an ophthalmologic apparatus. Such a program can be stored in any computer-readable recording medium. Examples of the recording medium include semiconductor memory, optical disk, magneto-optical disk (CD-ROM/DVD-RAM/DVD-ROM/MO, etc.), magnetic storage medium (hard disk/floppy (registered trademark) disk/ZIP, etc.). can be used. It is also possible to transmit and receive this program through a network such as the Internet or LAN.

1, 1a ophthalmic apparatus 10, 10a optical system 11, 11A, 11B ellipsoidal mirror 20, 20A, 20B optical scanner 40 collimator lens unit 100 OCT unit 101 light source unit 130 DAQ
200 Arithmetic control unit 210 Control unit 211 Main control unit 212 Storage unit 212A Timing information 220 Image forming unit 230 Data processing unit 300 Display device E Eye to be examined LS Measurement light

Claims (14)

A concave mirror and an optical scanner that deflects measurement light and guides it to the reflecting surface of the concave mirror, and is arranged at the position of the eye to be examined or its conjugate position using optical coherence tomography using the measurement light reflected by the reflecting surface an acquisition unit that acquires data of the eye to be inspected by executing an A-scan on the eye to be inspected;
The data is obtained based on the measurement light deflected at substantially equal intervals of deflection angles over the entire deflection angle range of the optical scanner by causing the acquisition unit to execute the A-scan at a timing corresponding to the deflection angle of the optical scanner . a control unit that acquires
ophthalmic equipment, including The concave mirror is an ellipsoidal mirror,
The optical scanner is arranged at or near the first focal point of the ellipsoidal mirror, or at or near the conjugate position of the first focal point,
The ophthalmologic apparatus according to claim 1, wherein the position of the eye to be examined is arranged at or near the second focal point of the ellipsoidal mirror, or at or near a conjugate position of the second focal point. including a storage unit that stores in advance the timing information of the A scan,
3. The ophthalmologic apparatus according to claim 1, wherein the control section causes the acquisition section to execute the A-scan based on the timing information. The timing information includes A-scan timing information based on the reference timing of the deflection operation of the optical scanner,
The ophthalmologic apparatus according to claim 3, wherein the control section causes the acquisition section to execute the A-scan at the timing specified by the timing information. The control unit acquires operation information representing a deflection angle of the optical scanner, determines whether the deflection angle is a predetermined deflection angle based on the acquired operation information, and determines whether the deflection angle is the predetermined deflection angle. The ophthalmologic apparatus according to any one of claims 1 to 4, wherein the acquisition unit is caused to execute the A-scan when the deflection angle is determined to be . 6. The controller according to any one of claims 1 to 5, wherein the control unit causes the acquisition unit to execute the A-scan so that intervals of incident angles of the measurement light at the positions of the eye to be inspected are substantially equal. 10. An ophthalmic device according to claim 1. 3. The control unit causes the acquisition unit to execute the A-scan so that the distances between projection positions of the collimated measuring beams are substantially equal in the anterior segment of the eye to be inspected. The ophthalmic device according to any one of claims 1 to 5 . A control method for an ophthalmic device including a concave mirror and an optical scanner that deflects measurement light and guides it to a reflecting surface of the concave mirror,
An acquisition step of acquiring data of the eye to be inspected by performing an A-scan on the eye to be inspected placed at a position of the eye to be inspected or its conjugate position using optical coherence tomography using measurement light reflected by the reflecting surface. and,
Control for acquiring the data based on the measurement light deflected at substantially equal intervals of deflection angles over the entire deflection angle range of the optical scanner by executing the A-scan at a timing corresponding to the deflection angle of the optical scanner . a step;
A method of controlling an ophthalmic device comprising: The concave mirror is an ellipsoidal mirror,
The optical scanner is arranged at or near the first focal point of the ellipsoidal mirror, or at or near the conjugate position of the first focal point,
The method of controlling an ophthalmologic apparatus according to claim 8 , wherein the position of the subject's eye is arranged at or near the second focal point of the ellipsoidal mirror, or at or near a conjugate position of the second focal point. 10. The method of controlling an ophthalmologic apparatus according to claim 8 , wherein the control step executes the A-scan based on pre-stored timing information for the A-scan. The timing information includes A-scan timing information based on the reference timing of the deflection operation of the optical scanner,
11. The method of controlling an ophthalmologic apparatus according to claim 10 , wherein the control step causes the A-scan to be performed at the timing specified by the timing information. The control step includes:
a motion information acquisition step of acquiring motion information representing the deflection angle of the optical scanner;
a determination step of determining whether the deflection angle is a predetermined deflection angle based on the acquired motion information;
an execution step of executing the A-scan when the deflection angle is determined to be the predetermined deflection angle in the determining step;
The method of controlling an ophthalmologic apparatus according to claim 11 , comprising: 13. The A-scan according to any one of claims 8 to 12 , characterized in that the control step causes the A-scan to be performed such that intervals of incident angles of the measurement light beams at the positions of the eye to be inspected are substantially equal. A control method for an ophthalmic device. The control step causes the A-scan to be performed so that the distances between the projection positions of the collimated measuring beams are substantially equal in the anterior ocular segment of the eye to be inspected. 13. The method of controlling an ophthalmologic apparatus according to any one of 12 .

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