JP7281906B2 - Ophthalmic device, its control method, program, and recording medium - Google Patents

Description

The present invention relates to an ophthalmologic apparatus, its control method, program, and recording medium.

According to recent research on the progression of myopia, the results of animal experiments show that the focal point of the peripheral part of the eye fundus is located closer to the sclera than the retinal surface when the central part of the fundus (fovea) is in focus. It has been reported that myopia progresses as a result of the retina trying to move to the back.

There are subjective refraction measurement and objective refraction measurement as methods for examining the refraction power of an eye. Subjective refraction measurement is a subjective test that determines the refraction power of a subject's eye according to the subject's response to a visual target (such as the Landolt's ring) presented to the subject's eye. Objective refraction measurement is an objective test that determines the refractive power of an eye to be inspected according to changes in the size and shape of the reflected light image of light projected onto the fundus of the eye to be inspected. A refractometer is used for objective refraction measurement.

Spectacle lenses and contact lenses are used to correct the refractive error of the eyeball. Conventional general lenses are aimed at correcting refractive error near the fovea. On the other hand, in recent years, in addition to correcting refractive error near the fovea, lenses capable of correcting refractive error around the fundus to suppress myopia progress have been used. Considering that there are individual differences in the distribution of the focus position of the fundus oculi, in order to effectively manage the risk of myopia, it is necessary to grasp the state of the focus position of the fundus oculi from the center to the periphery of the eye to be examined. However, it is considered effective to observe the morphology of the fundus oculi.

In order to measure the focus position of the peripheral part of the eye fundus, the direction of the line of sight of the subject's eye can be moved so that the measurement light of the refractometer is irradiated to a desired location. However, the principle of the refractometer is to obtain the refractive power of the entire eyeball, and it has been impossible to grasp the morphological change of the fundus of the eye, which is the main change accompanying the progression of myopia. In addition, it has been difficult with conventional techniques to measure the local refractive power of the eyeball with high resolution.

Japanese Patent Application Laid-Open No. 2002-017676 JP 2009-291253 A JP 2016-041221 A

Earl L. Smith III, Li-Fang Hung, Juan Huang, “Relative peripheral hyperopic defocus alters central refractive development in infant monkeys”, Vision Research Volume 49, Issue 19, 30 September 2009, Pages 2386-2392

SUMMARY OF THE INVENTION It is an object of the present invention to automatically determine optimal focus parameters for OCT scanning.

An ophthalmologic apparatus according to a first aspect of an exemplary embodiment includes an OCT unit that applies an optical coherence tomography (OCT) scan to the fundus of a subject eye to construct an image, and and an evaluation process of analyzing each of the plurality of images acquired by the OCT unit corresponding to each of a plurality of different focus states and calculating an image quality evaluation value. and a determination processing unit that determines an optimum value of a focus parameter based on a plurality of image quality evaluation values calculated from the plurality of images.

A second aspect of the exemplary embodiment is the ophthalmic apparatus of the first aspect, wherein a plurality of OCT scans corresponding to a plurality of different focus states are applied to each of the plurality of scan lines. , further includes a first scan control unit that controls the OCT unit and the optical member, and the evaluation processing unit performs a plurality of scan lines constructed based on the plurality of OCT scans, respectively, for each of the plurality of scan lines. A plurality of image quality evaluation values are calculated from the two-dimensional image, and the determination processing unit determines an optimum value of the focus parameter for each of the plurality of scan lines based on the plurality of image quality evaluation values.

A third aspect of the exemplary embodiment is the ophthalmic apparatus of the second aspect, wherein the first scan controller, for each of the plurality of scan lines, determines the The OCT unit and the optical members are controlled to apply an OCT scan with the optimum values.

A fourth aspect of the exemplary embodiment is the ophthalmic apparatus of the second aspect, wherein for any of the plurality of scan lines, the optimum value corresponding to the scan line determined by the determination processing unit is selected. a first selection processor that selects one of the plurality of two-dimensional images corresponding to the scan line based on the scan line.

A fifth aspect of the exemplary embodiment is the ophthalmic apparatus of the first aspect, wherein a plurality of OCT scans corresponding to a plurality of different focus states are applied to each of the plurality of scan points. further includes a second scan control unit that controls the OCT unit and the optical member, and the evaluation processing unit performs a plurality of scan points constructed based on the plurality of OCT scans, respectively, for each of the plurality of scan points. A plurality of image quality evaluation values are respectively calculated from the one-dimensional image, and the determination processing unit determines an optimum value of the focus parameter based on the plurality of image quality evaluation values for each of the plurality of scanning points.

A sixth aspect of the exemplary embodiment is the ophthalmologic apparatus of the fifth aspect, wherein the first It further includes a first creation processing unit that creates a map.

A seventh aspect of the exemplary embodiment is the ophthalmologic apparatus of the fifth aspect, wherein the deviation of the optimum value corresponding to each of the plurality of scanning points determined by the determination processing unit from a predetermined reference value is determined. A second creation processing unit for calculating and creating a second map representing a distribution of a plurality of deviations respectively corresponding to the plurality of scan points.

An eighth aspect of the exemplary embodiment is the ophthalmologic apparatus of the fifth aspect, wherein for any one of the plurality of scan points, the optimum value corresponding to the scan point determined by the determination processing unit is selected. a second selection processor that selects one of the plurality of one-dimensional images corresponding to the scan point based on the scan point.

A ninth aspect of the exemplary embodiments is the ophthalmologic apparatus according to any one of the first to eighth aspects, wherein the determination processing unit obtains approximate curves for at least some of the plurality of image quality evaluation values. , the optimum value is determined from the maximum value of the approximated curve.

A tenth aspect of the exemplary embodiments is the ophthalmologic apparatus according to any one of the first to ninth aspects, wherein the optical member is arranged in the optical path of the measurement light and has a predetermined degree of sphericity. The above first lens is included.

An eleventh aspect of the exemplary embodiment is the ophthalmologic apparatus of the tenth aspect, wherein the optical member includes one or more second lenses arranged in the optical path of the measurement light and having a predetermined degree of astigmatism. include.

A twelfth aspect of the exemplary embodiment is an OCT unit that applies an optical coherence tomography (OCT) scan to the fundus of an eye to be examined to construct an image; A method of controlling an ophthalmic apparatus including an optical member for changing a focus state and a processor, the method comprising: causing the OCT unit to acquire a plurality of images respectively corresponding to a plurality of different focus states; a step of causing the processor to execute a process of analyzing each of the images and calculating an image quality evaluation value; and a process of determining an optimum value of a focus parameter based on the plurality of image quality evaluation values respectively calculated from the plurality of images. and causing the processor to execute:

A thirteenth aspect of the exemplary embodiments is a program that causes an ophthalmologic apparatus including a computer to execute the control method of the twelfth aspect.

A fourteenth aspect of the exemplary embodiments is a computer-readable non-transitory recording medium recording the program of the thirteenth aspect.

According to an exemplary embodiment, it is possible to automatically determine optimal focus parameters for OCT scanning.

1 is a schematic diagram illustrating an example configuration of an ophthalmic apparatus according to an exemplary embodiment; FIG. 1 is a schematic diagram illustrating an example configuration of an ophthalmic apparatus according to an exemplary embodiment; FIG. 1 is a schematic diagram illustrating an example configuration of an ophthalmic apparatus according to an exemplary embodiment; FIG. 1 is a schematic diagram illustrating an example configuration of an ophthalmic apparatus according to an exemplary embodiment; FIG. FIG. 4 is a schematic diagram for explaining an example of processing performed by an ophthalmologic apparatus according to an exemplary embodiment; 4 is a flow chart representing an example of the operation of an ophthalmic device according to an exemplary embodiment; 4 is a flow chart representing an example of the operation of an ophthalmic device according to an exemplary embodiment; 4 is a flow chart representing an example of the operation of an ophthalmic device according to an exemplary embodiment; 4 is a flow chart representing an example of the operation of an ophthalmic device according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of the operation of an ophthalmologic apparatus according to an exemplary embodiment;

An ophthalmologic apparatus, its control method, program, and recording medium according to exemplary embodiments will be described in detail with reference to the drawings. The disclosure content of the documents cited in this specification and any other known technology can be incorporated into the embodiments. Unless otherwise specified, "image data" and "images" based thereon are not distinguished. Also, unless otherwise specified, the "part" of the subject's eye and its "image" are not distinguished.

An ophthalmic device according to an exemplary embodiment can measure the fundus of a live eye using Fourier-domain OCT (eg, swept-source OCT). The type of OCT applicable to embodiments is not limited to swept source OCT, but may be spectral domain OCT or time domain OCT, for example.

Exemplary embodiments may be capable of processing images acquired by modalities other than OCT. For example, exemplary embodiments may be capable of processing images acquired by any of fundus cameras, SLOs, slit lamp microscopes, and ophthalmic surgical microscopes. Ophthalmic devices according to exemplary embodiments may include any of fundus cameras, SLOs, slit lamp microscopes, and ophthalmic surgical microscopes.

<composition>
The ophthalmic apparatus 1 of the exemplary embodiment shown in FIG. 1 includes a fundus camera unit 2, an OCT unit 100 and an arithmetic and control unit 200. As shown in FIG. The retinal camera unit 2 is provided with an optical system and a mechanism for acquiring a front image of the subject's eye. The OCT unit 100 is provided with a part of an optical system and a mechanism for performing OCT. Another part of the optical system and mechanism for performing OCT is provided in the fundus camera unit 2 . The arithmetic control unit 200 includes one or more processors that perform various arithmetic operations and controls. In addition to these, arbitrary elements such as a member for supporting the subject's face (chin rest, forehead rest, etc.) and a lens unit for switching the target part of OCT (for example, attachment for anterior segment OCT) or unit may be provided in the ophthalmologic apparatus 1 .

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 e), CPLD (Complex 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.

<Fundus camera unit 2>
The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef of the eye E to be examined. The acquired image of the fundus oculi Ef (referred to as a fundus image, fundus photograph, etc.) is a front image such as an observed image or a photographed image. Observation images are obtained, for example, by moving image shooting using near-infrared light, and are used for alignment, focusing, tracking, and the like. The captured image is a still image using flash light in the visible range or the infrared range, for example.

The fundus camera unit 2 includes an illumination optical system 10 and an imaging optical system 30 . The illumination optical system 10 irradiates the eye E to be inspected with illumination light. The imaging optical system 30 detects return light of illumination light from the eye E to be examined. The measurement light from the OCT unit 100 is guided to the subject's eye E through the optical path in the retinal camera unit 2, and its return light is guided to the OCT unit 100 through the same optical path.

Light (observation illumination light) output from the observation light source 11 of the illumination optical system 10 is reflected by the concave mirror 12, passes through the condenser lens 13, passes through the visible cut filter 14, and becomes near-infrared light. Furthermore, the observation illumination light is once converged near the photographing light source 15 , reflected by the mirror 16 , and passed through the relay lens system 17 , the relay lens 18 , the diaphragm 19 and the relay lens system 20 . The observation illumination light is reflected by the periphery of the perforated mirror 21 (area around the perforation), passes through the dichroic mirror 46, is refracted by the objective lens 22, and illuminates the eye E (fundus oculi Ef). do. The return light of the observation illumination light from the subject's eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central region of the apertured mirror 21, and passes through the dichroic mirror 55. , through a focusing lens 31 and reflected by a mirror 32 . Further, this return light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the image sensor 35 by the imaging lens . The image sensor 35 detects returned light at a predetermined frame rate. The focus (focal position) of the imaging optical system 30 is typically adjusted to match the fundus oculi Ef or the anterior segment of the eye.

The light (imaging illumination light) output from the imaging light source 15 irradiates the fundus oculi Ef through the same path as the observation illumination light. The return light of the imaging illumination light from the subject's eye E is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33 , is reflected by the mirror 36 , is reflected by the imaging lens 37 . An image is formed on the light receiving surface of the image sensor 38 .

A liquid crystal display (LCD) 39 displays a fixation target (fixation target image). A part of the light beam output from the LCD 39 is reflected by the half mirror 33 A, reflected by the mirror 32 , passes through the focusing lens 31 and the dichroic mirror 55 , and passes through the aperture of the apertured mirror 21 . The luminous flux that has passed through the aperture of the perforated mirror 21 is transmitted through the dichroic mirror 46, refracted by the objective lens 22, and projected onto the fundus oculi Ef.

By changing the display position of the fixation target image on the screen of the LCD 39, the fixation position of the subject's eye E by the fixation target can be changed. Examples of fixation positions include a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, and a position between the macula and the optic disc. There are a fixation position for acquiring a central image and a fixation position for acquiring an image of a site (eyeground periphery) far away from the macula. A graphical user interface (GUI) or the like may be provided for specifying at least one such exemplary fixation position. Further, a GUI or the like for manually moving the fixation position (the display position of the fixation target) can be provided.

The configuration for presenting a fixation target whose fixation position is changeable to the subject's eye E is not limited to a display device such as an LCD. For example, a fixation matrix in which a plurality of light-emitting units (light-emitting diodes, etc.) are arranged in a matrix (array) can be employed instead of the display device. In this case, the fixation position of the subject's eye E by the fixation target can be changed by selectively lighting a plurality of light emitting units. As another example, one or more movable light emitters can generate a fixation target whose fixation position can be changed.

The alignment optical system 50 generates an alignment index used for alignment of the optical system with respect to the eye E to be examined. Alignment light output from a light-emitting diode (LED) 51 passes through an aperture 52, an aperture 53, and a relay lens 54, is reflected by a dichroic mirror 55, passes through the aperture of the perforated mirror 21, and passes through the dichroic mirror 46. It is transmitted and projected onto the subject's eye E via the objective lens 22 . Return light of the alignment light from the subject's eye E (corneal reflected light, etc.) is guided to the image sensor 35 through the same path as return light of the observation illumination light. Manual alignment or automatic alignment can be performed based on the received light image (alignment index image).

As in the conventional case, the alignment index image of this example consists of two bright spot images whose positions change depending on the alignment state. When the relative positions of the subject's eye E and the optical system change in the xy direction, the two bright spot images are displaced together in the xy direction. When the relative position between the subject's eye E and the optical system changes in the z direction, the relative position (distance) between the two bright spot images changes. When the distance between the subject's eye E and the optical system in the z direction matches the predetermined working distance, the two bright spot images overlap. When the position of the subject's eye E and the position of the optical system match in the xy direction, two bright point images are presented within or near a predetermined alignment target. When the distance between the eye to be examined E and the optical system in the z direction matches the working distance, and the position of the eye to be examined E and the position of the optical system in the xy direction match, the two bright spot images are superimposed for alignment. Presented within the target.

In auto-alignment, the data processing unit 230 detects the positions of the two bright spot images, and the main control unit 211 controls the moving mechanism 150, which will be described later, based on the positional relationship between the two bright spot images and the alignment target. . In manual alignment, the main control unit 211 causes the display unit 241 to display two luminescent spot images together with the observed image of the eye E, and the user operates the operation unit 242 while referring to the two displayed luminescent spot images. to operate the moving mechanism 150 .

The focus optical system 60 generates a split index used for focus adjustment of the eye E to be examined. The focus optical system 60 is moved along the optical path of the illumination optical system 10 (illumination optical path) in conjunction with the movement of the imaging focusing lens 31 along the optical path of the imaging optical system 30 (imaging optical path). The reflecting bar 67 is inserted into and removed from the illumination optical path. When performing focus adjustment, the reflecting surface of the reflecting bar 67 is arranged at an angle in the illumination optical path. Focus light output from the LED 61 passes through a relay lens 62, is split into two light beams by a split index plate 63, passes through a two-hole diaphragm 64, is reflected by a mirror 65, and is reflected by a condenser lens 66 onto a reflecting rod 67. is once imaged on the reflective surface of , and then reflected. Further, the focused light passes through the relay lens 20 , is reflected by the perforated mirror 21 , passes through the dichroic mirror 46 , and is projected onto the subject's eye E via the objective lens 22 . The return light of the focus light from the subject's eye E (reflected light from the fundus, etc.) is guided to the image sensor 35 through the same path as the return light of the alignment light. Manual focusing and autofocusing can be performed based on the received light image (split index image).

Diopter correction lenses 70 and 71 can be selectively inserted in the imaging optical path between the apertured mirror 21 and the dichroic mirror 55 . The dioptric correction lens 70 is a plus lens (convex lens) for correcting high hyperopia. The dioptric correction lens 71 is a minus lens (concave lens) for correcting strong myopia.

The dichroic mirror 46 synthesizes the fundus imaging optical path and the OCT optical path (measurement arm). The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for photographing the fundus. The measurement arm is provided with a collimator lens unit 40, a retroreflector 41, a dispersion compensation member 42, an OCT focusing lens 43, an optical scanner 44, and a relay lens 45 in order from the OCT unit 100 side.

The retroreflector 41 is movable in directions indicated by arrows in FIG. 1 (incoming and outgoing directions of the measurement light LS). Thereby the length of the measuring arm is changed. The change in measurement arm length is used, for example, to correct the optical path length according to the axial length of the eye, correct the optical path length according to the shape of the fundus, and adjust the state of interference.

The dispersion compensating member 42 works together with a dispersion compensating member 113 (described later) arranged on the reference arm to match the dispersion characteristics of the measurement light LS and the reference light LR.

The OCT focusing lens 43 is movable along the direction indicated by the arrow in FIG. 1 (the optical axis of the measurement arm) to adjust the focus of the measurement arm. Thereby, the focus state (focus position, focal length) of the measurement arm is changed. The ophthalmologic apparatus 1 may be capable of controlling the movement of the imaging focusing lens 31, the movement of the focusing optical system 60, and the movement of the OCT focusing lens 43 in a coordinated manner.

The optical scanner 44 is substantially arranged at a position optically conjugate with the pupil of the eye E to be examined. A light scanner 44 deflects the measuring light LS guided by the measuring arm. The optical scanner 44 is, for example, a galvanometer scanner capable of two-dimensional scanning, including a galvanometer mirror for scanning in the x direction and a galvanometer mirror for scanning in the y direction. In this case, typically, either one of the two galvanometer mirrors is arranged at a position optically conjugate with the pupil of the eye to be examined E, or a pupil conjugate position is arranged between the two galvanometer mirrors. As a result, the OCT scan can be applied to the posterior segment of the eye with the position within the pupil of the subject's eye E or its vicinity as a pivot, and a wide range of the fundus oculi Ef can be scanned.

<OCT unit 100>
As illustrated in FIG. 2, the OCT unit 100 is provided with optical systems and mechanisms for applying swept-source OCT. This optical system includes interference optics. This interference optical system divides light from a wavelength tunable light source (wavelength swept light source) into measurement light and reference light, and superimposes 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. Interference light is generated together and the interference light is detected. A detection result (detection signal) obtained by the interference optical system is a signal (interference signal) representing the spectrum of the interference light, and is sent to the arithmetic control unit 200 (image constructing section 220).

The light source unit 101 includes, for example, a near-infrared tunable laser that changes the wavelength of emitted light at high speed. Light L0 output from the light source unit 101 is guided to the polarization controller 103 through the optical fiber 102, and the polarization state is adjusted. Further, the light L0 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 optical path of the measurement light LS is called a measurement arm or the like, and the optical path of the reference light LR is called a reference arm or the like.

The reference light LR is guided by the optical fiber 110 to the collimator 111 and converted into a parallel beam, and guided to the retroreflector 114 via the optical path length correction member 112 and the dispersion compensation member 113 . The optical path length correction member 112 is an optical element for matching the optical path length of the reference light LR and the optical path length of the measurement light LS. The dispersion compensation member 113 works together with the dispersion compensation member 42 arranged on the measurement arm to match the dispersion characteristics between the reference light LR and the measurement light LS. The retroreflector 114 is movable along the optical path of the reference beam LR incident on it, thereby changing the length of the reference arm. Changing the reference arm length is used, for example, to correct the optical path length according to the axial length of the eye, correct the optical path length according to the shape of the fundus, and adjust the interference state.

The reference light LR that has passed through the retroreflector 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 and its polarization state is adjusted. The polarization controller 118 is an optical member for adjusting the state of interference, and is used, for example, to optimize the intensity of interference between the measurement light LS and the reference light LR. After passing through the polarization controller 118 , the reference light LR is guided to the attenuator 120 through the optical fiber 119 to adjust the light amount, and guided to the fiber coupler 122 through the optical fiber 121 .

On the other hand, the measurement light LS generated by the fiber coupler 105 is guided to the collimator lens unit 40 through the optical fiber 127 and converted into a parallel light flux. The measurement light LS emitted from the collimator lens unit 40 passes through the retroreflector 41, the dispersion compensation member 42, the OCT focusing lens 43, the optical scanner 44 and the relay lens 45, is reflected by the dichroic mirror 46, and is refracted by the objective lens 22. and projected onto the eye E to be examined. The measurement light LS is scattered and reflected at various depth positions of the eye E to be examined. The return light of the measurement light LS from the subject's eye E travels in the opposite direction along the same path as the forward path, is guided to the fiber coupler 105 , and reaches the fiber coupler 122 via the optical fiber 128 .

The fiber coupler 122 superimposes the measurement light LS input via the optical fiber 128 and the reference light LR input via the optical fiber 121 to generate interference light. The fiber coupler 122 splits the generated interference light at a predetermined splitting ratio (for example, 1:1) to generate a pair of interference lights LC. A pair of interference lights LC are guided to detector 125 through optical fibers 123 and 124, respectively.

Detector 125 includes, for example, a balanced photodiode. A balanced photodiode has a pair of photodetectors that respectively detect a pair of interference lights LC, and outputs a difference between a pair of detection results obtained by these. Detector 125 sends this output (detection signal) to data acquisition system (DAQ) 130 .

A clock KC is supplied from the light source unit 101 to the data collection system 130 . The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength tunable light source. The light source unit 101, for example, splits the light L0 of each output wavelength to generate two split lights, optically delays one of these split lights, combines these split lights, and produces the resulting combined light. A clock KC is generated based on the detection result. The data acquisition system 130 samples the detection signal input from the detector 125 based on the clock KC. Data acquisition system 130 sends the results of this sampling to arithmetic and control unit 200 .

In this example, both an element for changing the measurement arm length (eg retroreflector 41) and an element for changing the reference arm length (eg retroreflector 114 or reference mirror) are provided. but only one element may be provided. Also, the elements for changing the difference (optical path length difference) between the measurement arm length and the reference arm length are not limited to these, and may be arbitrary elements (optical members, mechanisms, etc.).

In this way, the swept source OCT splits the light from the wavelength tunable light source into the measurement light and the reference light, and superimposes the return light of the measurement light from the object on the reference light to generate the interference light. In this method, interference light is detected by a photodetector, and an image is constructed by applying Fourier transform or the like to detection data collected according to wavelength sweeping and measurement light scanning.

On the other hand, spectral domain OCT divides light from a low coherence light source (broadband light source) into measurement light and reference light, and generates interference light by superimposing the return light of the measurement light from the object on the reference light. , the spectrum distribution of this interference light is detected by a spectroscope, and the detected spectrum distribution is subjected to Fourier transform or the like to construct an image.

That is, the swept-source OCT is an OCT technique that acquires the spectral distribution of interference light by time division, and the spectral domain OCT is an OCT technique that acquires the spectral distribution of interference light by space division.

<Control system/Processing system>
3 and 4 show configuration examples of the control system and the processing system of the ophthalmologic apparatus 1. FIG. The control section 210, the image constructing section 220 and the data processing section 230 are provided in the arithmetic control unit 200, for example. The ophthalmologic apparatus 1 may include a communication device for data communication with an external apparatus. The ophthalmologic apparatus 1 may include a drive device (reader/writer) for reading data from a recording medium and writing data to the recording medium.

<Control unit 210>
The control unit 210 executes various controls. Control unit 210 includes main control unit 211 and storage unit 212 . Further, as shown in FIG. 4, the controller 210 of this embodiment includes a scan controller 213 and a focus controller 214 . These are included in the main controller 211 .

<Main control unit 211>
The main controller 211 includes a processor and controls each element of the ophthalmologic apparatus 1 (including the elements shown in FIGS. 1 to 4). The main control unit 211 is implemented by cooperation between hardware including a processor and control software.

The main control unit 211 can operate the scan control unit 213 and the focus control unit 214 in a coordinated manner (synchronously). As a result, the OCT scan and focus adjustment are performed in a coordinated manner (synchronously).

Under the control of the main control unit 211, the imaging focus driving unit 31A moves the imaging focusing lens 31 arranged in the imaging optical path and the focus optical system 60 arranged in the illumination optical path. A retroreflector (RR) drive unit 41A moves the retroreflector 41 provided on the measurement arm under the control of the main control unit 211 . The OCT focus drive section 43A moves the OCT focus lens 43 arranged on the measurement arm under the control of the main control section 211 (focus control section 214). The optical scanner 44 provided on the measurement arm operates under the control of the main controller 211 (scan controller 213). A retroreflector (RR) driver 114A moves the retroreflector 114 placed on the reference arm under the control of the main controller 211 . Each of the drive units described above includes an actuator such as a pulse motor that operates under the control of the main control unit 211 .

The moving mechanism 150 moves, for example, at least the retinal camera unit 2 three-dimensionally. In a typical example, the moving mechanism 150 includes an x stage that can move in ±x directions (horizontal direction), an x moving mechanism that moves the x stage, and a y stage that can move in ±y directions (vertical direction). , a y-moving mechanism for moving the y-stage, a z-stage movable in the ±z direction (depth direction), and a z-moving mechanism for moving the z-stage. Each of these moving mechanisms includes an actuator such as a pulse motor that operates under control of the main control section 211 .

<Storage unit 212>
The storage unit 212 stores various data. The data stored in the storage unit 212 include OCT images, fundus images, eye information, control parameters, and the like.

The eye information to be examined includes subject information such as a patient ID and name, left/right eye identification information, electronic medical record information, and the like.

Control parameters include, for example, parameters (scan parameters) used for controlling OCT scanning and parameters (focus parameters) used for focus (focus position, focal length) control.

The scan parameters are parameters that indicate at least the content of control over the optical scanner 44 . The scan parameters may further include parameters indicating details of control over the light source unit 101 .

Examples of scan parameters include a parameter indicating a scan position, a parameter indicating a scan pattern, a parameter indicating a scan speed, a parameter indicating a scan interval, and the like. The scan speed is defined, for example, as the A-scan repetition rate. The scan interval is defined, for example, as the interval between adjacent A scans, that is, the interval between scan points.

Montage imaging (OCT scanning) can be performed in some embodiments. In the montage imaging, OCT scanning is sequentially applied to a plurality of mutually different regions of the fundus oculi Ef.

Two adjacent regions among the plurality of regions to which the montage shooting is applied may have parts in common with each other. In other words, with respect to the first and second regions that are adjacent to each other among the plurality of regions, a portion of the first region and a portion of the second region may overlap each other. This overlapping area (common area) is referred to as, for example, a margin for determining the relative positions of the first area and the second area in a montage (panorama synthesis).

The scan parameters related to montage shooting may include parameters (whole area parameters) indicating attributes of the entire area to which montage shooting is applied. Examples of overall area parameters include shape parameters, size parameters, and position parameters of the overall area.

The scan parameters for montage photography may include parameters (partial area parameters) indicating attributes of a plurality of areas, each of which is part of the entire area. Examples of partial area parameters include a shape parameter, a size parameter, a position parameter of each partial area, a parameter indicating the arrangement of a plurality of partial areas, a parameter indicating the order of applying OCT scans to the plurality of partial areas, and the like.

The focus parameter is a parameter that indicates the content of control for the OCT focus driving section 43A. Examples of focus parameters include a parameter indicating the focus position of the measurement arm, a parameter indicating the movement speed of the focus position, a parameter indicating the movement acceleration of the focus position, and the like.

The parameter indicating the focal position is, for example, a parameter indicating the position of the OCT focusing lens 43 or a parameter indicating the refractive power realized by the OCT focusing lens 43 . The parameter indicating the moving speed of the focal position is, for example, a parameter indicating the moving speed of the OCT focusing lens 43 . A parameter indicating the movement acceleration of the focal position is, for example, a parameter indicating the movement acceleration of the OCT focusing lens 43 . The moving speed may or may not be constant. The same applies to movement acceleration.

The focus parameter may contain information corresponding to each of a plurality of areas to which montage shooting is applied. For example, the focus parameters may include one or more focus positions corresponding to each partial area.

When two or more focus positions are associated with one partial area, the focus parameter may include information indicating the range to which each focus position is applied together with these focus positions. The information indicating the applicable range of the focal position is expressed as, for example, information indicating two or more subsets (identification numbers of B-scan lines, etc.) when a plurality of B-scans included in the partial region are taken as a whole set. .

<Scan control unit 213>
The scan controller 213 controls the optical scanner 44 based on the scan parameters. The scan controller 213 may further control the light source unit 101 . Details of the processing executed by the scan control unit 213 will be described later. The scan control unit 213 is implemented by cooperation between hardware including a processor and scan control software.

<Focus control unit 214>
The focus control section 214 controls the OCT focus driving section 43A based on the focus parameter. Details of the processing executed by the focus control unit 214 will be described later. The focus control unit 214 is implemented by cooperation between hardware including a processor and focus control software.

As will be described later, the scan control unit 213 and the focus control unit 214 of this embodiment can coordinately execute the movement of the OCT focusing lens 43 and the OCT scan according to the scan parameter and the focus parameter. As a result, the ophthalmologic apparatus 1 of the present embodiment acquires a plurality of OCT images corresponding to a plurality of focus states different from each other, analyzes these OCT images, and obtains new focus parameters (for example, the OCT focusing lens 43 realized refractive power) value or its distribution can be determined.

<Image constructing unit 220>
The image constructing unit 220 includes a processor, and constructs OCT image data of the fundus oculi Ef based on the signal (sampling data) input from the data acquisition system 130 . The OCT image data constructed by the image construction unit 220 is one or more pieces of A-scan image data, typically B-scan image data (two-dimensional tomographic image data) composed of a plurality of pieces of A-scan image data.

The process of constructing OCT image data includes noise removal (noise reduction), filtering, fast Fourier transform (FFT), etc., as in conventional Fourier domain OCT. For other types of OCT devices, the image builder 220 performs known processing depending on the type.

The image constructing unit 220 constructs three-dimensional data of the fundus oculi Ef based on the signal input from the data acquisition system 130 . This three-dimensional data is three-dimensional image data representing a three-dimensional region (volume) of the fundus oculi Ef. The three-dimensional image data means image data in which pixel positions are defined by a three-dimensional coordinate system. Examples of three-dimensional image data include stack data and volume data.

Stack 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 these scan lines. That is, stack data is an image 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). Data. Alternatively, the stack data is obtained by three-dimensionally arranging a plurality of A-scan image data respectively acquired for a plurality of scan points (scan point array) arranged two-dimensionally based on the positional relationship of these scan points. It is the obtained image data.

Volume data is image data whose pixels are voxels arranged three-dimensionally, and is also called voxel data. Volume data is constructed by applying interpolation processing, voxelization processing, etc. to stack data.

The image building section 220 renders the three-dimensional image data to build a display image. Examples of applicable rendering methods include volume rendering, surface rendering, maximum intensity projection (MIP), minimum intensity projection (MinIP), multiplanar reconstruction (MPR), and the like.

The image constructing unit 220 can construct an OCT en-face image (OCT en-face image) based on the three-dimensional image data. For example, the image constructing unit 220 can construct projection data by projecting three-dimensional image data in the z direction (A-line direction, depth direction). Also, the image constructing unit 220 can construct a shadowgram by projecting a part of the three-dimensional image data in the z-direction.

The partial 3D image data projected to construct the shadowgram are set using, for example, segmentation. Segmentation is the process of identifying subregions in an image. Typically, segmentation is used to identify image regions corresponding to predetermined tissues of the fundus oculi Ef. Segmentation is performed by the image construction unit 220 or the data processing unit 230, for example.

The ophthalmic device 1 may be capable of performing OCT-Angiography. OCT angiography is an imaging technique that constructs an image in which retinal vessels and choroidal vessels are emphasized (see, for example, Japanese Unexamined Patent Application Publication No. 2015-515894). In general, the fundus tissue (structure) does not change with time, but the blood flow portion inside the blood vessel changes with time. In OCT angiography, an image is generated by emphasizing a portion (blood flow signal) where such temporal changes exist. OCT angiography is also called OCT motion contrast imaging. Images obtained by OCT angiography are called angiographic images, angiograms, motion contrast images, and the like.

When OCT angiography is performed, the ophthalmologic apparatus 1 repeatedly scans the same region of the fundus oculi Ef a predetermined number of times. In montage OCT angiography, for example, repeated scanning can be applied sequentially in the order indicated by the scan parameters to a plurality of partial regions of the array indicated by the scan parameters. In another example, a series of OCT scans in the order indicated by the scan parameters for multiple partial regions of the array indicated by the scan parameters can be repeated a predetermined number of times. Focus parameters can be used along with scan parameters in montage OCT angiography. For example, it is possible to sequentially and repeatedly scan a plurality of partial regions in the array indicated by the scan parameters in the order indicated by the scan parameters and in the focus state indicated by the focus parameters. In another example, a series of OCT scans in the order indicated by the scan parameters and in the focus state indicated by the focus parameters for a plurality of partial regions in the array indicated by the scan parameters can be repeated a predetermined number of times.

Image constructor 220 can construct motion contrast images from the data sets collected by data acquisition system 130 in such repeated scans. This motion contrast image is an angiographic image obtained by emphasizing temporal changes in interference signals caused by blood flow in the fundus oculi Ef. Typically, OCT angiography is applied to a three-dimensional region of the fundus oculi Ef to obtain an image representing the three-dimensional distribution of blood vessels in the fundus oculi Ef.

When OCT angiography is performed, the image constructing unit 220 can construct arbitrary two-dimensional angiographic image data and/or arbitrary pseudo three-dimensional angiographic image data from the three-dimensional angiographic image data. is. For example, the image construction unit 220 can construct two-dimensional angiographic image data representing an arbitrary section of the fundus oculi Ef by applying multi-planar reconstruction to the three-dimensional angiographic image data. In addition, the image construction unit 220 constructs a front image representing a slab of any of the superficial, middle, and deep layers of the retina from the three-dimensional angiographic image data, and constructs a slab of the choroid (such as the choroidal capillary plate). It is possible to construct a frontal image representing

The image construction unit 220 is implemented by cooperation of hardware including a processor and image construction software.

<Data processing unit 230>
The data processing unit 230 includes a processor and applies various data processing to the image of the eye E to be examined. For example, the data processing unit 230 is implemented by cooperation of hardware including a processor and data processing software.

The data processing unit 230 can perform alignment (registration) between the two images acquired for the fundus oculi Ef. For example, the data processing unit 230 can perform registration between the three-dimensional image data acquired by OCT and the front image acquired by the fundus camera unit 2 . The data processor 230 can also perform registration between two OCT images obtained by OCT. The data processing section 230 can also perform registration between two front images acquired by the retinal camera unit 2 . It is also possible to apply registration to the analysis result of the OCT image and the analysis result of the front image. Registration can be performed by known techniques, including feature point extraction and affine transformation, for example.

As shown in FIG. 4 , the data processing section 230 of this embodiment includes an evaluation processing section 231 , a determination processing section 232 , a selection processing section 233 , a creation processing section 234 and a synthesis processing section 235 .

<Evaluation processing unit 231>
The ophthalmologic apparatus 1 of the present embodiment combines the movement of the focus of the measurement arm (the movement of the OCT focusing lens 43) and the repeated application of the OCT scan to generate a plurality of OCT images corresponding to a plurality of different focus states. to get

The evaluation processing unit 231 analyzes each of the acquired OCT images to calculate an image quality evaluation value. The image quality evaluation value is an arbitrary parameter that quantitatively expresses the quality of the OCT image, and may be, for example, a parameter that quantitatively expresses the imaging state of the measurement light. Typically, the higher the quality of the OCT image, the higher the image quality evaluation value.

As an example of a method for calculating an image quality evaluation value, a known method for calculating an Image Quality value will be described below. First, the evaluation processing unit 231 applies predetermined analysis processing (for example, segmentation) to the OCT image of the fundus oculi Ef to obtain an image region (tissue image region) corresponding to the fundus tissue (retina, choroid, etc.) and image regions (non-tissue image regions) are detected. Next, the evaluation processing unit 231 generates a histogram based on the tissue image region and a histogram based on the non-tissue image. Subsequently, the evaluation processing unit 231 calculates an image quality evaluation value based on how these two histograms overlap. For example, in the range of 0 to 100, the image quality evaluation value = 0 when both histograms are completely overlapped, and the image quality evaluation value = 100 when both histograms are completely separated. An image quality rating value is defined.

In this way, the evaluation processing unit 231 analyzes each of the plurality of OCT images acquired corresponding to the plurality of focus states different from each other, thereby obtaining a plurality of image quality evaluation values respectively corresponding to the plurality of OCT images. calculate.

<Decision processing unit 232>
The determination processing unit 232 determines the optimum value of the focus parameter based on the multiple image quality evaluation values calculated from the multiple OCT images by the evaluation processing unit 231 .

For example, the determination processing unit 232 performs a process of obtaining an approximated curve for at least some of the plurality of image quality evaluation values calculated by the evaluation processing unit 231, and a process of determining the optimum value of the focus parameter from the maximum value of this approximated curve. to run. An example of a series of processes for obtaining the optimum value of the focus parameter will be described below.

As described above, the ophthalmologic apparatus 1 of this embodiment can correspond to a plurality of different focus states by combining the movement of the focus of the measurement arm (the movement of the OCT focusing lens 43) and the repeated application of the OCT scan. Acquire multiple OCT images for As a specific example of this operation, the focus control unit 214 moves the OCT focusing lens 43 in a range from -10 diopters (D) to +10D. At this time, the OCT focusing lens 43 is moved, for example, in units of 1D. That is, the focus control unit 214 controls -10D, -9D, -8D, -7D, -6D, -5D, -4D, -3D, -2D, -1D, 0D, 1D, 2D, 3D, 4D, 5D, The OCT focusing lens 43 is arranged at positions (focus positions) corresponding to 6D, 7D, 8D, 9D, and 10D.

When the OCT focusing lens 43 is arranged at each of these focus positions, the scan control unit 213 performs OCT scanning (for example, B scanning or three-dimensional scanning). These OCT scans are applied to substantially the same region (eg, two-dimensional cross-section or three-dimensional region) of the fundus oculi Ef. As a result, 21 OCT images corresponding to these focus positions are obtained.

The evaluation processing unit 231 analyzes each of the 21 OCT images and calculates an image quality evaluation value. As a result, 21 image quality evaluation values corresponding to 21 OCT images are obtained. That is, 21 image quality evaluation values corresponding to 21 different focus positions are obtained.

The determination processing unit 232 first obtains approximate curves for at least some of the 21 image quality evaluation values. Typically, the determination processing section 232 selects a plurality of image quality evaluation values from 21 image quality evaluation values according to a predetermined condition. For example, the determination processing unit 232 compares each of the 21 image quality evaluation values with a threshold and selects image quality evaluation values equal to or greater than the threshold. Alternatively, the determination processing unit 232 selects a predetermined number of image quality evaluation values from among the 21 image quality evaluation values in descending order.

Next, the determination processing unit 232 obtains approximate curves of the selected plurality of image quality evaluation values. This approximation curve is, for example, a quadratic curve. Subsequently, the determination processing unit 232 obtains the maximum value of this quadratic curve.

Finally, the decision processing unit 232 decides the optimum value of the focus parameter from this maximum value. For example, the determination processing unit 232 can obtain the position (diopter value, etc.) of the OCT focusing lens 43 corresponding to the maximum value of the quadratic curve, and adopt it as the optimum value of the focus parameter. Alternatively, the decision processing unit 232 obtains a diopter value (generally a real number) corresponding to the maximum value of the quadratic curve, obtains the nearest integer value to this diopter value or a decimal value of predetermined significant digits, and It can be adopted as the optimum value of the focus parameter.

The line graph shown in FIG. 5 is defined in a two-dimensional coordinate system with the position (diopter value) of the OCT focusing lens 43 on the horizontal axis and the image quality evaluation value on the vertical axis. That is, this line graph represents the aforementioned 21 image quality evaluation values. Here, plotted points indicated by small rhombuses have image quality evaluation values less than a predetermined threshold. On the other hand, plotted points indicated by large rectangles have image quality evaluation values equal to or greater than the predetermined threshold.

In this example, a quadratic curve is obtained that approximates a plurality of plotted points indicated by large rectangles. This quadratic curve is upwardly convex, and typically the maximum point (maximum value) is arranged at or near the plotted point where the image quality evaluation value is the maximum. The optimum value of the focus parameter is determined based on the diopter value corresponding to this maximum point.

<Selection processing unit 233>
The selection processing unit 233 selects one OCT image from a plurality of OCT images corresponding to a plurality of focus states. An example of processing executed by the selection processing unit 233 will be described later.

<Creation processing unit 234>
The creation processing unit 234 creates a map representing the distribution of the optimum values of the focus parameters obtained for each of the plurality of positions on the fundus oculi Ef. An example of processing executed by the creation processing unit 234 will be described later.

<Synthesis processing unit 235>
The composition processing unit 235 constructs a composite image of a plurality of OCT images constructed by montage imaging. Image synthesis is performed by a known technique.

When two adjacent OCT images have a common area, the synthesis processing unit 235, for example, performs registration between the images drawn in the mutual common area to determine the relative position between these two OCT images. can decide.

If a common area is not provided, the composition processing unit 235 determines the arrangement of the plurality of OCT images corresponding to the plurality of partial areas according to the arrangement of the plurality of partial areas set by the area setting unit 231, for example. can be done.

<User Interface 240>
User interface 240 includes display unit 241 and operation unit 242 . Display unit 241 includes display device 3 . The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device, such as a touch panel, that combines a display function and an operation function. It is also possible to construct embodiments that do not include at least a portion of user interface 240 . For example, the display device may be an external device connected to the ophthalmic equipment.

<motion>
Several examples of the operation of the ophthalmologic apparatus 1 will be described. It is assumed that preparatory processing similar to the conventional one, such as patient ID input, fixation target presentation, fixation position adjustment, alignment, focus adjustment, and OCT optical path length adjustment, has already been performed.

<First operation example>
A first operation example of the ophthalmologic apparatus 1 is shown in FIG.

(S1: Move the OCT focusing lens to the initial position)
First, the focus control section 214 controls the OCT focus drive section 43A so as to move the OCT focus lens 43 to a predetermined initial position.

The initial position is a position corresponding to the first applied focus position among the plurality of pre-ordered focus positions. When the aforementioned 21 focus positions (-10D to +10D) are applied, for example, "-10D" is the first, "-9D" is the second, and "-8D" is the third. , "-7D" fourth, "-6D" fifth, "-5D" sixth, "-4D" seventh, "-3D" eighth , "-2D" at the 9th, "-1D" at the 10th, "0D" at the 11th, "1D" at the 12th, "2D" at the 13th, "3D " is the 14th, "4D" is the 15th, "5D" is the 16th, "6D" is the 17th, "7D" is the 18th, and "8D" is the 19th. , "9D" is set to the 20th, and "10D" is set to the 21st, respectively.

(S2: apply OCT scan)
After the OCT focusing lens 43 is placed in the initial position, the scan controller 213 applies an OCT scan to the fundus oculi Ef. The image construction unit 220 constructs an OCT image from the data collected by the OCT scan.

(S3: Have all focus positions been applied?)
If all of the multiple focus positions have been applied (S3: Yes), the process proceeds to step S5. If any of the multiple focus positions has not yet been applied (S3: No), the process proceeds to step 4.

For example, when the aforementioned 21 focus positions (-10D to +10D) are applied, steps S1 to S4 are repeatedly executed until all 21 focus positions are applied, and when all 21 focus positions are applied Move to step S5.

(S4: Change focus position)
If any of the plurality of focus positions has not yet been applied (S3: No), the focus control unit 214 moves the OCT focusing lens 43 to the position corresponding to the focus position in the order following the last applied focus position. , the OCT focus drive unit 43A is controlled to move the .

For example, when the 21 focus positions (−10D to +10D) described above are applied, and the last applied focus position is the k-th focus position, the focus control unit 214 selects the k+1-th focus position. The OCT focus driving section 43A is controlled so as to move the OCT focus lens 43 to the position corresponding to the position (k=1 to 20).

(S5: Calculate image quality evaluation value)
When all of the multiple focus positions are applied (S3: Yes), multiple OCT images corresponding to the multiple focus positions are obtained. For example, in the case where the above-mentioned 21 focus positions (−10D to +10D) are applied, if all of these 21 focus positions are applied, 21 OCT images corresponding to these 21 focus positions are obtained. be done.

The evaluation processing unit 231 analyzes each of a plurality of OCT images respectively corresponding to a plurality of focus positions to calculate an image quality evaluation value. Thereby, a plurality of image quality evaluation values corresponding to a plurality of focus positions are obtained.

(S6: Determining the optimum value of the focus parameter)
The decision processing unit 232 decides the optimum value of the focus parameter based on the plurality of image quality evaluation values obtained in step S5. For example, the determination processing unit 232 obtains an approximated curve for at least some of the plurality of image quality evaluation values obtained in step S5, and determines the optimum value of the focus parameter from the maximum value of this approximated curve.

(S7: Move the OCT focusing lens to the position corresponding to the optimum value)
The focus control unit 214 controls the OCT focus drive unit 43A so as to move the OCT focus lens 43 to the position corresponding to the optimum value of the focus parameter determined in step S6.

(S8: OCT scan applied at optimal focus position)
After the focus state of the measurement arm is optimized in step S7, the scan control unit 213 applies an OCT scan to the fundus oculi Ef. Thereby, an OCT image in an optimally focused state can be obtained.

According to this operation example, it is possible to automatically search and optimize the focus state for OCT scanning.

<Second operation example>
A second operation example of the ophthalmologic apparatus 1 is shown in FIG. In this example, an OCT scan (B scan) is applied to a plurality of cross sections of the fundus oculi Ef. The OCT scan pattern of this example is typically one of raster scan (three-dimensional scan), radial scan, cross scan, and multi-cross scan.

The scan pattern applied in this example is set in advance. The scan pattern includes a plurality of pre-ordered scan lines. Multiple scan lines correspond to multiple cross-sections.

(S11: Set B-scan target to initial cross section)
First, the scan control unit 213 sets scan parameters for applying the B scan to the first cross section (initial cross section) of the plurality of cross sections. The scan parameters include parameters indicating scan positions. The parameter indicating the scan position includes, for example, a parameter indicating the orientation of a mirror (galvanomirror or the like) included in the optical scanner 44 .

(S12: Move OCT focusing lens to initial position)
After the B-scan target is set to the initial slice, the focus control unit 214 controls the OCT focus driving unit 43A to move the OCT focus lens 43 to a predetermined initial position. This step is executed in the same manner as step S1 in the first operation example.

(S13: apply OCT scan)
After the OCT focusing lens 43 is placed in the initial position, the scan controller 213 applies an OCT scan to the first slice. The image construction unit 220 constructs an OCT image from the data collected by the OCT scan. This step is executed in the same manner as step S2 in the first operation example.

(S14: Have all focus positions been applied?)
When all of the multiple B-scans corresponding to the multiple focus positions have been applied to the first cross section (S14: Yes), the process proceeds to step S16. If the B-scan corresponding to any one of the plurality of focus positions has not yet been applied to the first cross section (S14: No), the process proceeds to step 15. This step is executed in the same manner as step S3 in the first operation example.

(S15: Change focus position)
If the B-scan corresponding to any one of the plurality of focus positions has not yet been applied to the first cross section (S14: No), the focus control unit 214 controls the focus position next to the last applied focus position. The OCT focus driving section 43A is controlled to move the OCT focus lens 43 to the position corresponding to the order focus position. This step is executed in the same manner as step S4 in the first operation example.

When all of the plurality of B-scans corresponding to the plurality of focus positions are applied to the first cross section (S14: Yes), the plurality of B scans for the first cross section respectively corresponding to the plurality of focus positions of OCT images are obtained.

(S16: Have you scanned all cross sections?)
When all of the multiple B-scans corresponding to the multiple focus positions have been applied to all cross sections (S16: Yes), the process proceeds to step S18. Otherwise (S16: No), the process proceeds to step S17.

(S17: Change the target cross section for B scan)
If B-scanning at all focus positions for all cross-sections has not been completed yet (S16: No), the scan control unit 213 sets scan parameters for applying B-scanning to cross-sections in the next order. This step is executed in the same manner as step S11.

(S18: Calculate the image quality evaluation value for each cross section)
When B-scanning is completed at all focus positions for all cross sections (S16: Yes), a plurality of OCT images corresponding to a plurality of focus positions are obtained for each of a plurality of cross sections.

The evaluation processing unit 231 analyzes each acquired OCT image to calculate an image quality evaluation value. Thereby, a plurality of image quality evaluation values corresponding to a plurality of focus positions are obtained for each of the plurality of cross sections. This step is executed in the same manner as step S5 in the first operation example.

(S19: Determining the optimum value of the focus parameter corresponding to each cross section)
The decision processing unit 232 decides the optimum value of the focus parameter for each of the multiple cross-sections based on the multiple image quality evaluation values obtained in step S18. This step is executed in the same manner as step S6 in the first operation example.

(S20: B scan is applied at the optimum focus position for each cross section)
The scan control unit 213 and the focus control unit 214 apply B-scan in the optimum focus state determined in step S19 to each of the plurality of slices.

In this step, for example, the main control unit 211 controls the scan control unit 213 to set the scan parameters according to the order set for the plurality of slices, and controls the focus control unit 214 to optimize the focus parameters. and the control for causing the scan control unit 213 to perform the B-scan in conjunction with each other. As a result, an OCT image in an optimally focused state can be obtained for each of a plurality of cross sections.

According to this operation example, it is possible to automatically search and optimize the focus state for OCT scanning for each of a plurality of cross sections.

<Third operation example>
A third operation example of the ophthalmologic apparatus 1 is shown in FIG. In this example, an OCT scan (B scan) is applied to a plurality of cross sections of the fundus oculi Ef as in the second operation example. In the second operation example, the OCT scan is performed again after obtaining the optimum focus position. select.

(S31-S39)
Steps S31 to S39 of this example are executed in the same manner as steps S11 to S19 of the second operation example.

(S40: For each cross section, select an image based on the optimum value)
The selection processing unit 233 selects one OCT image for each of the multiple cross-sections based on the optimum value of the focus parameter corresponding to the cross-section from among the multiple OCT images acquired for the cross-section.

The image selection in this step includes, for example, a process of specifying the diopter value closest to the optimum value and a process of selecting the OCT image corresponding to the specified diopter value. In addition, a single OCT image may be constructed by selecting a plurality of two or more OCT images and synthesizing (for example, averaging) these OCT images.

Thereby, a plurality of OCT images respectively corresponding to a plurality of cross sections are selected.

(S41: constructing a three-dimensional image from selected images of a plurality of cross sections)
The image constructing unit 220 (or data processing unit 230) constructs a three-dimensional image from a plurality of OCT images respectively corresponding to the plurality of slices selected in step S40. For example, the image constructing unit 220 can construct stack data by arranging a plurality of OCT images according to the arrangement of a plurality of slices. Furthermore, volume data can be constructed from this stack data.

According to this operation example, it is possible to automatically search for the optimum focus state corresponding to each cross section, and select an OCT image corresponding to this optimum focus state. When an OCT image is selected for each of a plurality of cross-sections, it is possible to construct a three-dimensional image with good focus on each cross-section.

<Fourth operation example>
A fourth operation example of the ophthalmologic apparatus 1 is shown in FIG. In this example, an OCT scan (B scan) is applied to a plurality of cross sections of the fundus oculi Ef as in the second operation example. In the second operation example, the optimum focus position of each cross section is obtained and the OCT scan is performed again. In this example, the optimum focus position of each scanning point is obtained and a map is created.

(S51-S57)
Steps S51 to S57 of this example are executed in the same manner as steps S11 to S19 of the second operation example.

(S58: Calculate image quality evaluation value for each scan point)
When B-scanning is completed at all focus positions for all cross-sections (S56: Yes), a plurality of OCT images corresponding to a plurality of focus positions are obtained for each of the plurality of cross-sections. Each of the multiple OCT images corresponding to each cross section consists of multiple A-scan images arranged in the cross section. As an example, for each of the 256 slices, 21 B-scan images corresponding to different diopter values are obtained, each B-scan image being formed from 256 A-scan images. The position of each A-scan image is defined by xy coordinates, and the position on the xy space indicated by the xy coordinates is the scan point.

If necessary, data processor 230 performs registration of the corresponding 21 B-scan images for each cross-section. Thus, 21 A-scan images are associated with each of the 256 scan points of each cross section. The evaluation processing unit 231 calculates an image quality evaluation value for each of the 21 A-scan images.

(S59: Determining the optimum value of the focus parameter corresponding to each scan point)
The decision processing unit 232 decides the optimum value of the focus parameter based on the plurality (for example, 21) image quality evaluation values calculated in step S58 for each scan point of each cross section.

(S60: create focus parameter map)
The creation processing unit 234 creates a map based on the group of optimal values of the focus parameters determined in step S59, that is, based on the optimal values of the focus parameters determined in step S59 for each scanning point of each cross section. do. The created map is information expressing the distribution of arbitrary focus parameters, and is called a focus parameter map.

In a first example, the creation processing unit 234 can create a map representing the distribution of these optimum values based on the group of optimum values of the focus parameters determined in step S59. This focus parameter map is typically information representing the optimum diopter value distribution.

In the second example, the creation processing unit 234 can first calculate the deviation of each optimum value from a predetermined reference value based on the group of optimum values of the focus parameters determined in step S59. This results in a family of deviations corresponding to a family of optimum values for the focus parameter. Further, the creation processing unit 234 can create a map representing the distribution of these deviations based on this group of deviations. This focus parameter map is typically information representing the distribution of indices (deviations) indicating how much the optimum diopter value at each scan point deviates from a predetermined reference value. Here, the predetermined reference value may be, for example, a preset value or a value set from the group of optimum values of the focus parameters determined in step S59. Typically, a statistic obtained from a group of optimal values (for example, average value, median value, maximum value, minimum value, etc.) can be set as the reference value.

The focus parameter map is not limited to these examples, and may be information representing the distribution of arbitrary parameters that can be calculated from the group of optimum values of the focus parameters determined in step S59 (and other data).

The expression mode of the focus parameter map is arbitrary. For example, the focus parameter map may be a map that expresses the magnitude of values (for example, diopter values) in a raster scan (three-dimensional scan) target area using contour lines. Also, contour lines may be represented by smooth lines (curves, straight lines, etc.) by applying a smoothing process to the contour lines. Smoothing processing may include interpolation processing for interpolating measurement points using a method such as linear interpolation or spline interpolation. The interpolation process includes, for example, a process of detecting an image area corresponding to the plane of the retinal pigment epithelium (RPE) of the fundus oculi Ef and a process of fitting the focus measurement point to the height profile of the image area of the RPE plane. may contain. Also, the magnitude of the value may be represented by color. For example, by dividing the entire range of value magnitudes into a plurality of intervals and assigning different colors to these intervals, the magnitudes of values can be displayed in different colors.

According to this operation example, for example, it is possible to create a focus parameter map in a target area of raster scanning (three-dimensional scanning).

<Fifth operation example>
A fifth operation example of the ophthalmologic apparatus 1 will be described. The OCT scan performed in this example is a montage imaging. In the montage imaging of this example, for example, as shown in FIG. 10, OCT scanning is applied to the entire area of 9 mm×9 mm in the xy space. This overall area is divided into 9 sub-areas arranged in 3 rows by 3 columns. The size of each partial area is 3 mm×3 mm. The numbers attached to the nine subregions indicate the order in which the OCT scans are applied.

Adjacent partial areas are provided with a common area (paste margin) so that the nine partial areas are arranged without gaps. The OCT scan for each partial area (and the common area surrounding it) is a raster scan. As shown in FIG. 10, each raster scan consists of 256 scan lines (256 B-scans) and each scan line consists of 256 scan points (256 A-scans).

When the montage photographing of this example is started, the ophthalmologic apparatus 1 applies a series of processes shown in steps S31 to S39 of the third operation example (FIG. 8) to nine partial regions in the above order. Thereby, the optimum focus position (optimum value of the focus parameter) corresponding to each scan line of each partial area is determined. Information indicating the determined optimum focus position is associated with the corresponding partial area and the corresponding scan line, and stored in the storage unit 212 or the data processing unit 230, for example.

Further, the ophthalmologic apparatus 1 applies raster scanning to each partial area at the corresponding optimum focus position. Alternatively, the selection processing unit 233 selects an OCT image based on the optimum focus position from among the already acquired OCT image group for each scan line of each partial region. Note that it is not necessary to obtain the optimum focus position for each scan line, and the optimum focus position may be obtained for each of a plurality of scan lines (for example, every 2 lines, every 8 lines, and every 16 lines).

As a result, 9 three-dimensional images (obtained in a good focus state) corresponding to 9 partial regions and 256 optimum values of focus parameters corresponding to each of the 9 partial regions (for example, , diopter value). Instead of obtaining the optimum value of the focus parameter for each B scan, the optimum value of the focus parameter may be obtained for each A scan. In this case, for example, 65536 (=256×256) focus parameter optimum values are obtained. Note that the optimum value of the focus parameter may be obtained for each of a plurality of A-scans.

The synthesis processing unit 235 performs registration of nine three-dimensional images based on the common area described above. Furthermore, the synthesizing unit 235 synthesizes the nine registered three-dimensional images to construct a three-dimensional image corresponding to the entire area of 9 mm×9 mm.

Further, the creation processing unit 234 creates a focus parameter map for the entire 9 mm×9 mm area based on the obtained group of optimum values of the focus parameters. This focus map is, for example, a two-dimensional contour map, and the data of each point may be smoothed. Smoothing processing may include interpolation processing for interpolating measurement points using a method such as linear interpolation or spline interpolation. The interpolation process may include, for example, a process of detecting an image area corresponding to the plane of the RPE of the fundus oculi Ef, and a process of fitting focus measurement points to the height profile of the image area of the RPE plane. A typical focus parameter map is a contour map that is color-coded according to the magnitude of the focus parameter value (diopter value, etc.).

<Sixth example of operation>
A sixth operation example of the ophthalmologic apparatus 1 will be described. In the fifth operation example, montage photography is performed by dividing the entire region into a plurality of partial regions and individually applying three-dimensional scanning. may be applied to the entire area.

When the 21 focus positions (−10D to +10D) described above are applied, for example, −10D is applied in the first three-dimensional scan and the second -9D is applied in the 3D scan of . . . , +10D is applied in the 21st 3D scan. As a result, 21 three-dimensional images corresponding to 21 focus positions are obtained.

The data processing unit 230 performs registration of the 21 3D images using one of the 21 3D images as a reference. After completing the registration, the data processing unit 230 divides the entire area of 9 mm×9 mm into a plurality of partial areas having a predetermined size and a predetermined arrangement. For example, the size of each partial image is set to 1 mm×1 mm, and the array is set to 9 rows×9 columns. A plurality of partial areas are associated with corresponding partial images in each of the 21 three-dimensional images. That is, 21 partial images corresponding to 21 three-dimensional images are associated with each partial area.

The evaluation processing unit 231 calculates an image quality evaluation value based on 21 partial images associated with each partial area. As a result, 21 image quality evaluation values corresponding to each partial area are obtained. Furthermore, the determination processing unit 232 determines the optimum value of the focus parameter based on the 21 image quality evaluation values corresponding to each partial area. As a result, the optimum values (for example, diopter values) of 81 focus parameters corresponding to the 81 partial regions are obtained.

For each of the 81 partial areas, the selection processing unit 233 selects a partial image (optimum partial image) obtained at a focus position closest to the optimum value of the corresponding focus parameter, and selects the partial image from the 21 partial areas associated with the partial area. You can choose from partial images. The control unit 210 can record the selection result by the selection processing unit 233 .

The synthesis processing unit 235 constructs a three-dimensional image corresponding to a wider range than one partial area by synthesizing 81 optimal partial images (at least part of them) corresponding to the 81 partial areas. be able to.

The creation processing unit 234 can create the focus parameter map based on the optimum values (at least some of them) of the 81 focus parameters respectively corresponding to the 81 partial areas.

〈Action and effect〉
Some actions and some effects of exemplary embodiments will be described.

An ophthalmic device according to an exemplary embodiment includes an optical coherence tomography (OCT) unit, an optical member, an evaluation processor, and a decision processor.

The OCT unit is configured to apply an OCT scan to the fundus of the subject eye to construct an image. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the OCT section includes an OCT unit 100 , elements in the fundus camera unit 2 forming a measurement arm, and an image construction section 220 .

The optical member is configured to change the focus state of measurement light with which the fundus is irradiated in OCT scanning. In the ophthalmic device 1 according to the exemplary embodiment, the optical member includes an OCT focusing lens 43 .

The evaluation processing unit is configured to analyze each of a plurality of images acquired by the OCT unit corresponding to a plurality of different focus states, respectively, and calculate an image quality evaluation value. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the evaluation processor includes an evaluation processor 231 .

The decision processing unit is configured to decide the optimum value of the focus parameter based on the plurality of image quality evaluation values calculated from the plurality of images. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the decision processor includes a decision processor 232 .

According to the ophthalmologic apparatus according to the exemplary embodiment, it is possible to automatically determine the optimum focus parameter based on the image quality of a plurality of OCT images actually acquired in a plurality of different focus states. Therefore, optimal focus parameters for OCT scanning can be easily obtained.

An ophthalmic device according to an exemplary embodiment may further include a first scan controller. The first scan control unit controls the OCT unit and the optical member so as to apply a plurality of OCT scans corresponding to a plurality of different focus states to each of the plurality of scan lines. In the ophthalmic apparatus 1 according to an exemplary embodiment, the first scan controller includes a scan controller 213 .

Further, the evaluation processing unit may be configured to calculate a plurality of image quality evaluation values from a plurality of two-dimensional images respectively constructed based on a plurality of OCT scans for each of the plurality of scan lines. Additionally, the decision processing unit may be configured to determine the optimum value of the focus parameter for each of the plurality of scan lines based on the plurality of image quality evaluation values.

With such a configuration, it is possible to automatically obtain the optimum focus parameter for each scan line.

In the ophthalmic apparatus according to an exemplary embodiment, a first scan control unit is configured to apply an OCT scan to each of the plurality of scan lines with the optimum values determined by the decision processing unit. It may be configured to control the member.

According to such a configuration, OCT scanning can be performed while applying the optimum focus parameter determined for each scan line. Therefore, it is possible to easily acquire an OCT image with good image quality for each scan line.

An ophthalmic device according to an exemplary embodiment may further include a first selection processor. A first selection processing unit selects one of a plurality of two-dimensional images corresponding to any one of the plurality of scan lines based on the optimum value corresponding to the scan line determined by the determination processing unit. to select. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the first selection processing section includes a selection processing section 233 .

According to such a configuration, an OCT image with good image quality can be automatically selected from among the plurality of OCT images acquired for determining the optimum focus parameter for each scan line. Furthermore, it is also possible to construct a three-dimensional image from multiple OCT images of good quality selected for multiple scanlines.

An ophthalmic device according to an exemplary embodiment may further include a second scan controller. The second scan control section controls the OCT section and the optical member so as to apply a plurality of OCT scans respectively corresponding to a plurality of different focus states to each of the plurality of scanning points. In the ophthalmic apparatus 1 according to an exemplary embodiment, the second scan controller includes a scan controller 213 .

Further, the evaluation processing unit may be configured to calculate a plurality of image quality evaluation values from a plurality of one-dimensional images respectively constructed based on a plurality of OCT scans for each of the plurality of scan points. Additionally, the determination processing unit may be configured to determine the optimum value of the focus parameter for each of the plurality of scan points based on the plurality of image quality evaluation values.

According to such a configuration, it is possible to automatically obtain the optimum focus parameter for each scanning point.

An ophthalmic device according to an exemplary embodiment may further include a first creation processor. A first creation processing unit creates a first map representing a distribution of a plurality of optimum values respectively corresponding to the plurality of scanning points determined by the determination processing unit. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the first creation processing section includes a creation processing section 234 .

According to such a configuration, it is possible to create a map that expresses the optimum focus parameter distribution.

The ophthalmic device according to the exemplary embodiment may further include a second creation processor. The second creation processing unit calculates a deviation from a predetermined reference value of the optimum value corresponding to each of the plurality of scanning points determined by the determination processing unit, and calculates a distribution of the plurality of deviations corresponding to each of the plurality of scanning points. Create a second map to represent In the ophthalmologic apparatus 1 according to the exemplary embodiment, the second creation processing section includes a creation processing section 234 .

According to such a configuration, it is possible to create a map that expresses the distribution of the focus position deviation.

An ophthalmic device according to an exemplary embodiment may further include a second selection processor. The second selection processing unit selects one of the plurality of one-dimensional images corresponding to the scanning point based on the optimum value corresponding to the scanning point determined by the determination processing unit for any of the plurality of scanning points. to select. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the second selection processing section includes a selection processing section 233 .

According to such a configuration, an OCT image with good image quality can be automatically selected from among the plurality of OCT images acquired for determining the optimum focus parameter for each scanning point. Furthermore, it is also possible to construct a two-dimensional image or a three-dimensional image from a plurality of good quality OCT images selected for a plurality of scan points.

In the ophthalmologic apparatus according to the exemplary embodiment, the determination processing unit performs a process of obtaining an approximated curve for at least a portion of the plurality of image quality evaluation values, and a process of determining the optimum value of the focus parameter from the maximum value of the approximated curve. may be configured to run

According to such a configuration, it is possible to provide a specific calculation for obtaining an optimum focus parameter from a plurality of image quality evaluation values.

In the ophthalmologic apparatus according to the exemplary embodiment, the optical member may include one or more first lenses arranged in the optical path of the measurement light and having a predetermined degree of sphericity.

When the number of first lenses included in the optical member is one, the focus state of the measurement arm can be changed by moving the first lens along the optical axis of the measurement arm. The ophthalmic apparatus 1 according to the exemplary embodiment is configured to change the focus state of the measurement arm by moving the OCT focusing lens 43 along the optical axis of the measurement arm.

When the number of first lenses included in the optical member is two or more, these first lenses are configured to be selectively insertable into the measurement arm. Note that the movement of the first lens along the optical axis and the selective insertion of the first lens may be combined.

According to such a configuration, it is possible to provide a specific aspect of the optical member for changing the focus state of the measurement light that irradiates the fundus.

In the ophthalmic apparatus according to the exemplary embodiment, the optical member may include one or more second lenses arranged in the optical path of the measurement light and having a predetermined degree of astigmatism. Any one of movement of the second lens along the optical axis, rotation of the second lens about the optical axis, and selective insertion of the second lens may be applied. You may combine two or more.

It should be noted that such a second lens is not provided in the ophthalmic apparatus 1 according to the exemplary embodiment, but it is possible to provide the second lens at a position adjacent to the OCT focusing lens 43, for example. .

According to such a configuration, it is possible to change the focus state of the measurement light with which the fundus is irradiated with higher accuracy.

Exemplary embodiments provide a method of controlling an ophthalmic device. An ophthalmic apparatus to which this control method is applied includes an OCT section, an optical member, and a processor. The OCT unit applies an OCT scan to the fundus of the subject's eye to construct an image. The optical member changes the focus state of the measurement light that irradiates the fundus in the OCT scan.

In the ophthalmologic apparatus 1 according to the exemplary embodiment, the OCT section includes an OCT unit 100 , elements in the fundus camera unit 2 forming a measurement arm, and an image construction section 220 . The optical members include OCT focusing lens 43 . The processor includes a control section 210 (at least a scan control section 213 and a focus control section 214) and a data processing section 230 (at least an evaluation processing section 231 and a decision processing section 232). This control method includes a first step, a second step, and a third step.

A first step causes the OCT unit to acquire a plurality of images respectively corresponding to a plurality of different focus states. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the scan control section 213 and the focus control section 214 execute the process of the first step.

A second step causes the processor to execute a process of analyzing each of the plurality of images and calculating an image quality evaluation value. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the evaluation processing section 231 executes the process of the second step.

A third step causes the processor to execute a process of determining the optimum value of the focus parameter based on the plurality of image quality evaluation values calculated from the plurality of images. In the ophthalmologic apparatus 1 according to the exemplary embodiment, the determination processing section 232 executes the process of the third step.

Any of the items described in the exemplary embodiments can be combined for such a method of controlling an ophthalmic device.

An exemplary embodiment provides a program that causes an ophthalmic device including a computer to execute such control method. Any of the items described in the exemplary embodiments can be combined for this program.

Also, it is possible to create a computer-readable non-transitory recording medium recording such a program. Any of the items described in the exemplary embodiments can be combined for this recording medium. Also, this non-temporary recording medium may be in any form, examples of which include magnetic disks, optical disks, magneto-optical disks, and semiconductor memories.

According to the control method, program, or recording medium according to the exemplary embodiment, automatically determining the optimum focus parameter based on the image quality of a plurality of OCT images actually acquired in a plurality of focus states different from each other. is possible. Therefore, optimal focus parameters for OCT scanning can be easily obtained. In addition, actions and effects according to items combined with the control method, program, or recording medium according to the exemplary embodiments are achieved.

The configurations described above are merely examples of embodiments of the present invention. Therefore, any modification (omission, substitution, addition, etc.) within the scope of the present invention is possible.

1 ophthalmic device 43 OCT focusing lens 43A OCT focusing driving unit 100 OCT unit 210 control unit 213 scan control unit 214 focus control unit 220 image construction unit 230 data processing unit 231 evaluation processing unit 232 decision processing unit 233 selection processing unit 234 creation Processing unit 235 Synthesis processing unit

Claims (7)

an OCT unit that applies an optical coherence tomography (OCT) scan to the fundus of the subject eye to construct an image;
an optical member for changing the focus state of measurement light irradiated to the fundus in the OCT scan;
an evaluation processing unit that analyzes each of the plurality of images acquired by the OCT unit corresponding to each of a plurality of different focus states and calculates an image quality evaluation value;
a determination processing unit that determines an optimum value of a focus parameter based on a plurality of image quality evaluation values calculated from the plurality of images ;
a scan control unit that controls the OCT unit and the optical member so as to apply a plurality of OCT scans corresponding to a plurality of different focus states to each of a plurality of scan points;
including
The evaluation processing unit calculates a plurality of image quality evaluation values from a plurality of one-dimensional images respectively constructed based on the plurality of OCT scans for each of the plurality of scan points,
The determination processing unit determines an optimum value of the focus parameter based on the plurality of image quality evaluation values for each of the plurality of scan points,
calculating the deviation from a predetermined reference value of the optimum value corresponding to each of the plurality of scanning points determined by the determination processing unit, and creating a map showing the distribution of the plurality of deviations respectively corresponding to the plurality of scanning points; further comprising a creation processing unit that
ophthalmic equipment. The determination processing unit obtains an approximated curve for at least a portion of the plurality of image quality evaluation values, and determines the optimum value from a maximum value of the approximated curve.
The ophthalmic device of claim 1 . The optical member includes one or more first lenses arranged in the optical path of the measurement light and having a predetermined spherical degree,
The ophthalmic device of claim 1 . The optical member includes one or more second lenses arranged in the optical path of the measurement light and having a predetermined degree of astigmatism,
4. The ophthalmic device of claim 3 . An OCT unit that applies an optical coherence tomography (OCT) scan to the fundus of an eye to construct an image, an optical member that changes the focus state of measurement light that irradiates the fundus in the OCT scan, and a processor. A method of controlling an ophthalmic device comprising:
a first step of causing the OCT unit to acquire a plurality of images respectively corresponding to a plurality of different focus states;
a second step of causing the processor to execute a process of analyzing each of the plurality of images and calculating an image quality evaluation value;
a third step of causing the processor to execute a process of determining an optimum value of a focus parameter based on a plurality of image quality evaluation values respectively calculated from the plurality of images,
The first step includes a fourth step of controlling the OCT unit and the optical member so as to apply a plurality of OCT scans corresponding to a plurality of different focus states to each of the plurality of scan points. including
The second step causes the processor to perform a process of calculating a plurality of image quality evaluation values from a plurality of one-dimensional images respectively constructed based on the plurality of OCT scans for each of the plurality of scan points. including steps
The third step includes a sixth step of causing the processor to execute a process of determining an optimum value of the focus parameter based on the plurality of image quality evaluation values for each of the plurality of scan points,
a process of calculating the deviation from a predetermined reference value of the optimum value corresponding to each of the plurality of scanning points determined in the sixth step; and a map representing the distribution of the plurality of deviations respectively corresponding to the plurality of scanning points. further comprising a seventh step of causing the processor to perform a process of creating
A control method for an ophthalmic device. A program for causing an ophthalmologic apparatus including a computer to execute the control method according to claim 5 . A computer-readable non-transitory recording medium in which the program according to claim 6 is recorded.

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