JP6936676B2 - Ophthalmic equipment - Google Patents

Description

The present invention relates to an ophthalmic apparatus that optically inspects an eye to be inspected.

In recent years, OCT, which measures or images the morphology of an object to be measured by using a light beam from a laser light source or the like, has attracted attention. Since OCT does not have invasiveness to the human body like X-ray CT (Computed Tomography), it is expected to be applied especially in the medical field and the biology field. For example, in the field of ophthalmology, devices for forming images of the fundus, cornea, etc. have been put into practical use. Such a device using OCT (OCT device) can be applied to observation of various parts (fundus and anterior eye) of the eye to be inspected. In addition, since it can acquire high-definition images, it is applied to the diagnosis of various ophthalmic diseases.

For example, Patent Document 1 discloses an ophthalmic apparatus capable of observing the anterior segment of the eye using OCT. According to such an ophthalmic apparatus, it is possible to specify the cross-sectional shape of the anterior segment by scanning the anterior segment of the eye, and to acquire information such as the shape of the front and back surfaces of the cornea, the thickness of the cornea, and the depth of the anterior chamber. Furthermore, by analyzing a plurality of cross-sectional shapes, it is possible to obtain a two-dimensional or three-dimensional distribution of the shape and thickness of the cornea and the depth of the anterior chamber of the anterior segment of the eye.

As a method of scanning the anterior segment of the eye, a radial scan is known in which a plurality of scans are performed radially around the pupil of the eye to be inspected. However, if the eye to be inspected moves due to fixed vision fine movement or line-of-sight shift during scanning, accurate information cannot be obtained. When scanning the fundus, a method of specifying the amount and direction of movement of the fundus due to fixation tremor, etc., based on the feature position in the frontal image of the fundus, and canceling the deviation of the scan position according to the specified amount of movement, etc. (Tracking) is known. However, when scanning the anterior segment of the eye, it is difficult to employ tracking as in the case of scanning the fundus because the anterior segment of the eye does not have a feature position.

Therefore, various methods for maintaining a suitable scanning position when scanning the anterior segment of the eye have been proposed.

For example, in Patent Document 2, an image of the anterior segment of the eye to be inspected is acquired, the apex position of the cornea is specified from the acquired image of the anterior segment of the eye, and the apex position of the cornea identified during acquisition of the tomographic image of the eye to be inspected. A method of aligning with reference to is disclosed.

Further, for example, Patent Document 3 discloses a method of monitoring the movement of the eye to be inspected by scanning a portion crossing a feature point different from the scan of the evaluation portion (imaging scan) (movement amount measurement scan). (See paragraph 0314, FIG. 22 in particular).

Further, for example, Patent Document 4 discloses a method of scanning the anterior segment of the eye using a scan pattern that combines a radial scan and a circular scan (particularly, paragraphs 0060 to 0062).

JP 2015-160103 Japanese Unexamined Patent Publication No. 2009-142313 Japanese Unexamined Patent Publication No. 2015-181789 Special Table 2014-500906 Gazette

However, in the conventional technique, the scan timing of the anterior segment and the acquisition timing of the image of the anterior segment are different. Therefore, due to the deviation between the scan timing and the image acquisition timing, the movement of the eye to be inspected identified using the acquired image and the deviation of the scan position do not match. As a result, the scan position cannot be corrected to an appropriate position.

Further, when the movement of the optical system is accompanied, it is difficult for the movement of the optical system to follow the fixation fine movement and the like, and vibration due to the movement of the optical system may occur. Further, if it is attempted to correct the deviation of the scan position due to the fixed vision fine movement during the scan only by the scan pattern, the scan time becomes long, and on the contrary, the eye to be inspected may move during the scan.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ophthalmic apparatus capable of accurately acquiring data of an eye to be inspected even if the eye to be inspected moves during scanning. It is in.

In the first aspect of the embodiment, the light from the optical scanner and the light source is divided into the measurement light and the reference light, the measurement light is projected onto the eye to be inspected through the optical scanner, and the measurement from the eye to be inspected is performed. An interfering optical system that detects the interference light between the return light of the light and the reference light, and a plurality of scans radially around the reference position in the anterior segment of the feature region in the anterior segment of the eye to be inspected. A control unit that controls the optical scanner to execute a radial scan, and a scan range that specifies a scan range in the crossing direction that intersects the traveling direction of the measurement light in the feature region based on the detection result of the interference light. A correction unit that corrects the misalignment of the scan center position of the radial scan based on the specific portion and the contour shape of the feature area, and a scan range of the scan in which the misalignment of the scan center position is corrected by the correction unit. This is an ophthalmic apparatus including a characteristic information calculation unit that calculates characteristic information of the anterior segment of the eye based on a detection result of interference light corresponding to the above.

Further, in the second aspect of the embodiment, in the first aspect, the correction unit may correct the misalignment so that the scan range falls within the feature area.

Further, in the third aspect of the embodiment, in the second aspect, the correction unit may correct the misalignment based on the length of the scan range and the scan angle of the scan with respect to the reference direction.

Further, in the fourth aspect of the embodiment, in the second or third aspect, in the correction unit, the end side of the scan range corresponding to the lower eyelid side of the eye to be inspected is arranged at the boundary of the feature region. The misalignment may be corrected as described above.

Further, the fifth aspect of the embodiment includes a detection unit that detects the occurrence of eclipse of the measurement light in the fourth aspect, and the correction unit is said to be said when the occurrence of the eclipse is detected by the detection unit. The misalignment may be corrected.

Further, in the sixth aspect of the embodiment, in any of the first to fifth aspects, the anterior segment imaging system for photographing the anterior segment of the eye to be inspected and the anterior segment imaging system are used. A specific portion that identifies the characteristic region in the acquired anterior eye portion image may be included.

In addition, the seventh aspect of the embodiment may include a shape correction unit that corrects the contour shape of the feature region based on the relative position of the anterior eye portion photographing system with respect to the eye to be inspected in the sixth aspect.

Further, the eighth aspect of the embodiment includes an image forming portion that forms a tomographic image of the eye to be inspected based on the detection result of the interference light in any of the first to seventh aspects, and specifies the scan range. The unit may specify the scan range based on the tomographic image formed by the image forming unit.

Further, the ninth aspect of the embodiment may include a characteristic distribution calculation unit for obtaining the distribution of the characteristic information of the anterior eye portion calculated by the characteristic information calculation unit in any of the first to eighth aspects. ..

Further, in the tenth aspect of the embodiment, in any one of the first to ninth aspects, the characteristic information may include at least one of corneal shape information, corneal film thickness information, and anterior chamber depth information.

Further, the eleventh aspect of the embodiment includes, in any one of the first to tenth aspects, a moving mechanism for relatively moving the eye to be inspected and the interference optical system, and the reference position is the eye to be inspected. It may be the alignment reference position of the interference optical system with respect to.

Further, in the twelfth aspect of the embodiment, in any of the first to eleventh aspects, the reference position may be the pupil center position, the pupil center of gravity position, the cornea center position, the cornea apex position or the eye center position. ..

Further, in the thirteenth aspect of the embodiment, in any one of the first to twelfth aspects, the characteristic region may be a region corresponding to the pupil, cornea, or iris of the eye to be inspected.

In addition, it is possible to arbitrarily combine the configurations according to the above-mentioned plurality of aspects.

According to the present invention, it is possible to provide an ophthalmic apparatus capable of accurately acquiring data of an eye to be inspected even if the eye to be inspected moves during scanning.

It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the process performed by the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is a flowchart which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on the modification of embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on the modification of embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on the modification of embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on the modification of embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on the modification of embodiment.

An example of an embodiment of the ophthalmic apparatus according to the present invention will be described in detail with reference to the drawings. The ophthalmic apparatus according to the present invention is used for an optical examination of an eye to be inspected. Such an ophthalmic apparatus includes an ophthalmologic imaging apparatus and an ophthalmologic measuring apparatus. Examples of the ophthalmologic imaging device include an optical coherence tomography, a fundus camera, a scanning laser ophthalmoscope, and a slit lamp. Further, as the ophthalmic measuring device, there are an ophthalmic refraction test device, a tonometer, a specular microscope, a wavefront analyzer and the like. In the following embodiments, the case where the present invention is applied to an optical coherence tomography will be described, but the present invention can be applied to an ophthalmic device that combines the functions of an optical coherence tomography and any other device. Is.

In this specification, images acquired by OCT may be collectively referred to as OCT images. Further, the measurement operation for forming an OCT image may be referred to as OCT measurement. In addition, the description content of the document described in this specification can be appropriately incorporated as the content of the following embodiment.

Further, in the following embodiment, an optical coherence tomography using a so-called spectral domain type OCT equipped with a low coherence light source and a spectroscope will be described. However, it is also possible to apply the present invention to optical coherence tomography using a type other than the spectral domain, for example, a Swept Source type, an Infas type OCT method. The swept source OCT scans (wavelength sweep) the wavelength of the light applied to the object to be measured, detects the interference light obtained by superimposing the reflected light of the light of each wavelength and the reference light, and detects the spectrum. This is a method of imaging the morphology of an object to be measured by acquiring an intensity distribution and applying a Fourier transform to it. Further, in-face OCT is to irradiate an object to be measured with light having a predetermined beam diameter and analyze the component of interference light obtained by superimposing the reflected light and the reference light. It is a method of forming an image of an object to be measured in a cross section orthogonal to the traveling direction of light, and is also called a full-field type.

The ophthalmic apparatus according to the embodiment can be used for switching from fundus measurement to anterior ocular segment measurement by inserting an optical element such as a front lens at a predetermined position in the optical system. The measurement target site is not limited to the fundus and anterior eye portion, and may be any site of the eye to be inspected, such as the vitreous body and the crystalline lens. Further, it is also possible to prepare optical elements according to the measurement target site and selectively apply them to the ophthalmic apparatus. It can also be configured to automatically select the use / non-use of an optical element such as a front lens and / or the applicable optical element. These selection processes are performed based on, for example, the shooting contents and the names of injuries and illnesses performed in the past.

In the following, the optical axis direction of the device optical system is the z direction (front-back direction), the horizontal direction orthogonal to the optical axis of the device optical system is the x direction (left-right direction), and the vertical direction orthogonal to the optical axis of the device optical system. Is the y direction (vertical direction).

[composition]
1 and 2 show a configuration example of the ophthalmic apparatus according to the embodiment. The ophthalmic apparatus 1 according to the embodiment includes a function of acquiring data of the eye to be inspected E, that is, a function of photographing the eye to be inspected E and / or a function of measuring the characteristics of the eye to be inspected E.

The ophthalmic apparatus 1 includes a processor 10, an optical system 20, an anterior eye camera 60, a face support 70, a first drive mechanism 80A, a second drive mechanism 80B, and a user interface (UI) unit 90. And include. The front eye camera 60 may be included in the optical system 20. It should be noted that the configuration may be such that only one of the first drive mechanism 80A and the second drive mechanism 80B is provided.

The optical system 20 is provided with an interference optical system 30, an optical scanner 40, an objective lens 50, and a front lens 51. The front lens 51 is configured to be removable between the eye E to be inspected and the objective lens 50. Two or more front-eye cameras 60 are provided at positions where the eye E to be inspected is seen from different angles with respect to the optical axis of the objective lens 50.

(Processor 10)
The processor 10 executes various types of information processing. In the present specification, the "processor" is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD (Simple It means a circuit such as Programmable Logic Device), FPGA (Field Programmable Gate Array)).

The processor 10 realizes the function according to the embodiment by reading and executing a program stored in a storage circuit or a storage device, for example. At least a part of the storage circuit and the storage device may be included in the processor 10. Further, at least a part of the storage circuit and the storage device may be provided outside the processor 10. The processing that can be executed by the processor 10 will be described later. The processor 10 includes a control unit 11, a storage unit 12, an image forming unit 13, and a data processing unit 14.

(Control unit 11)
The control unit 11 controls each unit of the ophthalmic apparatus 1. In particular, the control unit 11 controls the optical system 20, the first drive mechanism 80A, and the second drive mechanism 80B.

The control for the optical system 20 includes a control for performing OCT measurement by the interference optical system 30. In order to execute the OCT measurement, the control unit 11 can control the optical scanner 40 so as to move the projection position of the measurement light in the eye E to be inspected according to a predetermined scan pattern. Scan patterns include three-dimensional scans, radial scans, line scans, and circle scans.

Further, the control unit 11 can control the alignment of the optical system 20 with respect to the eye E to be inspected. In the case of manual alignment, the control unit 11 receives an operation on the user interface unit 90 by the user and controls at least one of the first drive mechanism 80A and the second drive mechanism 80B to control the optical system 20 and the eye E to be inspected. Move relative to each other. In the case of auto-alignment, the control unit 11 controls at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the relative position between the optical system 20 and the eye to be inspected E, thereby controlling the optical system 20 and the eye to be inspected. Move relative to E. The control unit 11 can move the optical system 20 and the eye E to be inspected relative to each other based on the relative position with respect to the eye to be inspected E obtained from the image captured by the front eye camera 60. The control that can be executed by the control unit 11 will be described later.

(Memory unit 12)
The storage unit 12 stores various types of data. The data stored in the storage unit 12 includes data acquired by the interference optical system 30 (measurement data, detection result of interference light, etc.), information on the subject and the eye to be examined, and the like. Various computer programs and data for operating the ophthalmic apparatus 1 may be stored in the storage unit 12. Various data used / referenced in the processing described later are stored in the storage unit 12. The storage unit 12 includes the above-mentioned storage circuit and storage device.

(Image forming unit 13)
The image forming unit 13 forms image data of a tomographic image, a two-dimensional image, or a three-dimensional image of the eye to be inspected based on the detection result of the interference light described later obtained by the interference optical system 30. This process includes processing such as noise removal (noise reduction), filter processing, and FFT (Fast Fourier Transform), as in the conventional spectral domain type optical coherence tomography. In the case of other types of OCT devices, the image forming unit 13 executes a known process according to the type.

(Data processing unit 14)
The data processing unit 14 executes various data processing. In particular, the data processing unit 14 analyzes the detection result of the interference light obtained by the interference optical system 30, the image of the eye to be inspected formed by the image forming unit 13, and the image acquired by the anterior eye camera 60. The data processing unit 14 is provided with an analysis unit 141. As shown in FIG. 2, the analysis unit 141 includes a feature area analysis unit 1411, a scan identification unit 1412, a shape correction unit 1413, a position correction unit 1414, a characteristic information calculation unit 1415, and a characteristic distribution calculation unit 1416. including. These operations will be described later.

(Optical system 20)
In addition to the configuration shown in FIG. 1, the optical system 20 may be provided with an optical system (observation optical system, photographing optical system, etc.) or an alignment optical system for photographing the eye E to be inspected from the front. Further, a configuration for focusing the interference optical system 30 may be provided. Further, the optical system 20 may include a light source (anterior eye portion illumination light source) for illuminating the anterior eye portion Ea of the eye E to be inspected.

(Interference optical system 30)
The interference optical system 30 is provided with an optical system for acquiring an OCT image of the fundus or anterior eye portion of the eye E to be inspected. This optical system has a configuration similar to that of a conventional spectral domain type OCT apparatus. That is, this optical system divides the light from the light source (low coherence light) into reference light and signal light, and interferes with the measurement light that has passed through the fundus or anterior segment of the eye and the reference light that has passed through the reference optical path. It is configured to generate light and detect the spectral components of this interfering light. This detection result (detection signal) is sent to the processor 10.

When this optical system has the same configuration as the swept source type OCT device, a wavelength sweep light source is provided instead of a light source that outputs a low coherence light source, and an optical member that spectrally decomposes the interference light is provided. I can't. In general, a known technique according to the type of OCT can be arbitrarily applied to the configuration of the interference optical system 30.

The optical system 20 may include a configuration for providing a function associated with the inspection. For example, an fixation optical system for projecting an optotype (fixation target) for fixing the eye E to be inspected on the fundus of the eye E may be provided.

(Optical scanner 40)
The optical scanner 40 changes the traveling direction of the measurement light. The optical scanner 40 is controlled by the processor 10 (control unit 11) and deflects the measurement light in a direction orthogonal to the traveling direction of the measurement light (in a broad sense, an intersecting direction) according to a predetermined scan pattern. Thereby, a desired portion in the fundus or anterior segment of the eye can be scanned with the measurement light according to the scan pattern. The optical scanner 40 includes, for example, a galvano mirror that scans the measurement light in the x direction, a galvano mirror that scans the measurement light in the y direction, and a mechanism that independently drives them. Thereby, the measurement light can scan in any direction on the xy plane.

(Front lens 51)
The front lens 51 is an optical member for changing the focal length of the objective lens 50. The front lens 51 is configured so that it can be inserted / retracted with respect to the optical path toward the eye E to be inspected. The anterior lens 51 is retracted from the optical path when performing OCT measurement of the fundus, and is arranged in the optical path when performing OCT measurement of the anterior eye portion. In this embodiment, the front lens 51 is inserted and removed between the eye E to be inspected and the objective lens 50, but may be arranged between the objective lens 50 and the optical scanner 40. When the anterior lens 51 is retracted from between the eye E to be inspected and the objective lens 50, the conjugate position of the optical scanner 40 is arranged near the pupil of the eye E to be inspected, and the ophthalmologic apparatus 1 can scan the fundus. .. When the anterior lens 51 is arranged between the eye to be inspected E and the objective lens 50, the conjugate position of the optical scanner 40 is moved to a position different from the anterior eye portion Ea of the eye to be inspected E, and the ophthalmologic apparatus 1 is moved to the front. The eye area Ea can be scanned.

(Anterior eye camera 60)
The anterior segment camera 60 captures the anterior segment Ea of the eye E to be inspected. As described above, two or more front-eye cameras 60 are provided at positions where the eye E to be inspected is seen from different angles with respect to the optical axis of the objective lens 50. Each front eye camera 60 is, for example, a video camera that shoots a moving image at a predetermined frame rate. The two or more anterior segment cameras 60 capture the anterior segment Ea from different directions substantially simultaneously. In this embodiment, as shown in FIGS. 3A, 3B, 4A and 4B, two front eye cameras 60A and 60B are provided.

FIG. 4A is a top view showing the positional relationship between the eye E to be inspected and the anterior eye cameras 60A and 60B. The + y direction indicates the vertical upper direction, and the + z direction indicates the optical axis direction of the objective lens 50 and the direction from the objective lens 50 toward the eye E to be inspected. FIG. 4B is a side view showing the positional relationship between the eye E to be inspected and the anterior eye cameras 60A and 60B. Each of the anterior segment cameras 60A and 60B is provided at a position outside the optical path of the interference optical system 30. Hereinafter, the two front eye cameras 60A and 60B may be collectively represented by reference numeral 60.

The number of front eye cameras may be any number of 2 or more, but any number of front eye cameras may be used as long as the front eye can be photographed substantially simultaneously from two different directions. Further, one front eye camera may be arranged coaxially with the objective lens 50.

“Substantially at the same time” means that in imaging with two or more anterior eye cameras, the deviation of the imaging timing to the extent that eye movements can be ignored is allowed. Thereby, the image when the eye E to be inspected is in the same position (orientation) can be acquired by two or more anterior eye cameras.

Further, the shooting with two or more front eye cameras may be a moving image shooting or a still image shooting, but in the present embodiment, a case where the moving image shooting is performed will be described in particular detail. In the case of moving image shooting, it is possible to realize substantially simultaneous front eye shooting as described above by controlling the shooting start timing to be adjusted, and controlling the frame rate and the shooting timing of each frame. On the other hand, in the case of still image shooting, this can be realized by controlling the shooting timing to be adjusted.

In this embodiment, two or more captured images obtained substantially simultaneously by two or more anterior eye cameras 60 are used for alignment of the optical system 20 and the eye E to be inspected. The alignment includes Z alignment in the optical axis direction (z direction) of the objective lens 50 and XY alignment in the x direction (horizontal direction) and y direction (vertical direction) orthogonal to the z direction.

In the present embodiment, the feature positions corresponding to the feature portions of the eye E to be inspected are specified for each of the two or more captured images obtained by the anterior eye camera 60, and the positions of the two or more identified as the front eye camera 60 are specified. The three-dimensional position of the feature portion of the eye E to be inspected is obtained based on the feature position in the captured image. The characteristic site includes, for example, a pupil center position, a pupil center of gravity position, a corneal center position, or a corneal apex position. In the case of manual alignment, the optical system 20 and the eye E to be inspected are operated by the user with respect to the user interface unit 90 so that the displacement of the position corresponding to the characteristic portion of the eye E to be inspected with respect to the predetermined alignment reference position is cancelled. To move relative to each other. In the case of auto-alignment, the control unit 11 three-dimensionally moves the optical system 20 and the eye E to be inspected relative to each other so that the displacement of the position corresponding to the characteristic portion of the eye E to be inspected with respect to the alignment reference position is cancelled. The alignment reference position may be a position where the optical axis of the optical system 20 substantially coincides with the axis of the eye to be inspected E and the distance of the optical system 20 to the eye to be inspected E is a predetermined operating distance. Here, the working distance is a default value, which is also called a working distance of the objective lens 50, and means a distance between the eye E to be inspected and the optical system 20 at the time of inspection using the interference optical system 30.

(Face support 70)
The face support portion 70 includes a member for supporting the face of the subject. For example, as shown in FIGS. 3A and 3B, the face support portion 70 includes a forehead pad on which the forehead of the subject is abutted and a chin rest on which the chin of the subject is placed. The face support portion 70 may include only one of the forehead pad and the chin rest, and may include members other than these.

In FIGS. 3A and 3B, the base 210 houses a drive system such as the first drive mechanism 80A and the second drive mechanism 80B, and the processor 10. The optical system 20 is housed in the housing 220 provided on the base 210. The objective lens 50 is housed in the lens housing unit 230. A lens accommodating portion 230 is provided so as to project from the front surface of the housing 220.

(1st drive mechanism 80A, 2nd drive mechanism 80B)
The first drive mechanism 80A moves the optical system 20 under the control of the control unit 11. The first drive mechanism 80A can move the optical system 20 three-dimensionally. The first drive mechanism 80A includes, for example, a mechanism for moving the optical system 20 in the x direction, a mechanism for moving the optical system 20 in the y direction, and a mechanism for moving the optical system 20 in the z direction, as in the conventional case. The first drive mechanism 80A includes a plurality of stepping motors (driving means) for driving a mechanism for moving in the x-direction, y-direction, and z-direction. For example, the control unit 11 can move the optical system 20 by a movement amount corresponding to the number of pulses by supplying a drive signal of a predetermined number of pulses to the stepping motor.

The second drive mechanism 80B moves the face support unit 70 under the control of the control unit 11. The second drive mechanism 80B can move the face support portion 70 three-dimensionally. The second drive mechanism 80B includes, for example, a mechanism similar to the first drive mechanism 80A. As described above, in general, at least one of the first drive mechanism 80A and the second drive mechanism 80B is provided. Further, the first drive mechanism 80A may move the optical system 20 three-dimensionally, and the second drive mechanism 80B may move the face support portion 70 only in the vertical direction.

(User interface unit 90)
The user interface unit 90 provides functions for exchanging information between the ophthalmic apparatus 1 and its user, such as information display, information input, and operation instruction input. The user interface unit 90 provides an output function and an input function. Examples of configurations that provide an output function include a display device such as a flat panel display, an audio output device, a print output device, and a data writer that writes to a recording medium. Examples of configurations that provide input functions include operating levers, buttons, keys, pointing devices, microphones, data writers, and the like. The user interface unit 90 may include a device such as a touch panel display in which an output function and an input function are integrated. Further, the user interface unit 90 may include a graphical user interface (GUI) for inputting / outputting information.

(Data processing unit 14)
The data processing unit 14 performs various data processing and analysis processing on the acquired interference light detection result and image. For example, the data processing unit 14 executes various correction processes such as image brightness correction and dispersion correction. As described above, the data processing unit 14 is provided with an analysis unit 141.

<Analysis unit 141>
The analysis unit 141 can perform an analysis process for performing alignment. As an example of the configuration for performing such an analysis process, the analysis unit 141 is provided with a feature area analysis unit 1411.

The analysis unit 141 analyzes two or more captured images obtained substantially at the same time by two or more anterior eye camera 60s to obtain a feature position corresponding to the feature portion of the eye E to be inspected. In this embodiment, the moving target position of the optical system 20 is determined based on the obtained feature position, and the first drive mechanism 80A or the like is controlled based on the determined moving target position.

<< Feature Area Analysis Unit 1411 >>
The feature area analysis unit 1411 analyzes each captured image obtained by the anterior eye portion camera 60, and thereby, a position (feature position and a feature position) in the captured image corresponding to a predetermined feature portion in the feature region of the anterior eye portion Ea. To identify). As the predetermined feature site, for example, the pupil center position, the pupil center of gravity position, the cornea center position, the corneal apex position, or the eye center position of the eye to be inspected E is used. Hereinafter, a specific example of the process for specifying the pupil center position of the eye E to be inspected will be described.

First, the feature region analysis unit 1411 identifies an image region (pupil region) corresponding to the pupil of the eye E to be inspected based on the distribution of pixel values (luminance values and the like) of the captured image. Since the pupil is generally drawn with a lower brightness than other parts, the pupil region can be specified by searching the low-brightness image region. At this time, the pupil region may be specified in consideration of the shape of the pupil. That is, it can be configured to specify the pupil region by searching for a substantially circular and low-luminance image region.

Next, the feature region analysis unit 1411 identifies the central position of the identified pupil region. Since the pupil is substantially circular as described above, the contour of the pupil region can be specified, the center position of this contour (approximate circle or approximate ellipse) can be specified, and this can be used as the pupil center position. Further, the center of gravity of the pupil region may be obtained, and the position of the center of gravity may be specified as the position of the center of gravity of the pupil.

Even when the feature position corresponding to another feature portion is specified, the feature position can be specified based on the distribution of the pixel values of the captured image in the same manner as described above.

The feature area analysis unit 1411 can sequentially identify the feature positions with respect to the captured images sequentially obtained by the two or more front eye camera 60s. Further, the feature area analysis unit 1411 may specify the feature positions at any one or more arbitrary number of frames with respect to the captured images sequentially obtained by the two or more front eye camera 60s.

Further, the feature area analysis unit 1411 is based on the positions of the two or more front eye camera 60s and the two or more positions corresponding to the feature parts in the two or more captured images specified by the feature area analysis unit 1411. It is possible to specify the three-dimensional position of the featured part. This process will be described with reference to FIGS. 4A and 4B.

In FIGS. 4A and 4B, the distance (baseline length) between the two anterior eye cameras 60A and 60B is represented by "B", the baselines of the two anterior eye cameras 60A and 60B, and the characteristic portion of the eye E to be inspected. The distance (shooting distance) from P is represented by "H". Further, the distance (screen distance) between the front eye cameras 60A and 60B and the screen plane thereof is represented by "f".

In such an arrangement state, the resolution of the images captured by the anterior eye cameras 60A and 60B is expressed by the following equation. Here, Δp represents the pixel resolution.

Resolution in the XY direction (planar resolution): ΔXY = H × Δp / f
Resolution in the Z direction (depth resolution): ΔZ = H × H × Δp / (B × f)

The feature area analysis unit 1411 is arranged as shown in FIGS. 4A and 4B with respect to the positions (known) of the two front eye cameras 60A and 60B and the positions corresponding to the feature parts P in the two captured images. By applying a known trigonometry in consideration of the relationship, it is possible to calculate the three-dimensional position of the feature portion P as the feature position.

The captured image to be analyzed by the feature area analysis unit 1411 may be one in which distortion is corrected in advance. In this case, the storage unit 12 stores in advance information about the distortion aberration generated in the captured image due to the influence of the optical system mounted on each front eye camera 60. Distortion aberration of the captured image is corrected based on the information stored in the storage unit 12.

The feature position specified by the feature area analysis unit 1411 is sent to the control unit 11 as a movement target position. Based on the movement target position, the control unit 11 has the positions of the optical axis of the optical system 20 in the x direction and the y direction coincide with the positions of the movement target position in the x direction and the y direction, and the distance in the z direction is set. At least one of the first drive mechanism 80A and the second drive mechanism 80B is controlled so as to have a predetermined working distance.

In addition, the analysis unit 141 can perform analysis processing for performing OCT measurement on the fundus and the anterior eye portion. The ophthalmic apparatus 1 according to the embodiment performs a radial scan on the anterior eye portion Ea in order to perform an OCT measurement on the anterior eye portion Ea (that is, a front lens 51 between the eye to be inspected E and the objective lens 50). Will be placed). Hereinafter, the case of performing OCT measurement on the anterior eye portion Ea will be mainly described as an example, but OCT measurement on the fundus of the eye subject E with the anterior lens 51 retracted from between the eye subject E and the objective lens 50 will be described. The same applies when performing.

FIG. 5 shows an explanatory diagram of the radial scan according to the embodiment. FIG. 5 schematically shows the trajectory of the projection position of the measurement light by the radial scan performed on the anterior eye portion Ea of the eye E to be inspected. In FIG. 5, the iris region AR0 and the pupil region AR1 are illustrated. In the radial scan, a plurality of scans are executed radially around a predetermined scan center position C. FIG. 5 shows a case where scanning in 16 directions is executed radially around the scanning center position C, but the number of scanning directions may be 2 or more. Scan SC1 represents a vertical scan. The scan SC2 represents a scan in a direction rotated by 11.25 ° clockwise with respect to the vertical direction about the scan center position C. The scan SC3 represents a scan in a direction rotated by 22.5 ° clockwise with respect to the vertical direction about the scan center position C. Similarly, the scan SC 16 represents a scan in a direction rotated clockwise by 168.75 ° with respect to the vertical direction about the scan center position C.

Normally, the scan center position C is arranged on the optical axis of the objective lens 50. When the optical axis of the objective lens 50 and the above-mentioned alignment reference position (alignment reference position) AL substantially match, the alignment is completed, and the scan center position C substantially matches the alignment reference position AL. The alignment reference position may be the center position of the pupil, the center of gravity of the pupil, the center position of the cornea, the apex position of the cornea, or the center position of the eye to be inspected. FIG. 5 shows a state in which the alignment is completed and the scan center position C substantially coincides with the center position (pupil center position) of the pupil region AR1 in the eye E to be inspected. The analysis unit 141 obtains the corneal surface shape, the corneal inner surface shape, the corneal film thickness, the anterior chamber depth, etc. from the cross-sectional shape of each meridian drawn in the tomographic image obtained by each scan as shown in FIG. It is possible to calculate a dimensional distribution or a three-dimensional distribution.

For example, the OCT measurement of the anterior segment Ea of the eye E to be inspected is started when the alignment of the optical system 20 with respect to the eye E to be inspected is completed. In the ophthalmic apparatus 1, when the relative positions of the eye E to be inspected and the optical system 20 are within a predetermined range due to the positions of two or more feature positions in two or more captured images acquired by two or more anterior eye cameras 60. It is judged that the alignment is completed. As a result, the alignment reference position AL and the scan center position C coincide with each other. When it is determined that the alignment is completed, the radial scan as shown in FIG. 5 is started. Since the optical system 20 does not move during scanning, the scan center position C of the scan pattern is fixed. If there is no movement of the eye E to be inspected, a radial scan is performed radially around the alignment reference position AL of the eye E to be inspected.

6A and 6B show an explanatory diagram of the operation of the radial scan in the ophthalmic apparatus according to the comparative example of the embodiment. FIG. 6A schematically shows a scan line of a radial scan in which scans SC1 to SC16 are performed radially around the scan center position C with respect to the pupil region AR1. FIG. 6B schematically shows the scan range in the pupil region AR1 obtained by the scans SC1 to SC16 of FIG. 6A.

As shown in FIG. 6A, since the scan center position C of the scan pattern is fixed, the scan is started by aligning with the alignment reference position AL, and if there is no movement of the eye E to be inspected, the alignment reference of the eye E to be inspected is used. Radial scans are performed radially around the position AL. Therefore, as shown in FIG. 6B, the scan result in the pupil region AR1 can be correctly acquired centering on the scan center position C.

However, the eye to be inspected may move due to fixation microtremor or the like during OCT measurement (during radial scan).

7A, 7B, 8A, and 8B show an explanatory diagram of the operation of the radial scan when the eye E to be inspected moves during the OCT measurement. Here, it is assumed that the scans SC1 to SC16 are performed in order. 7A and 7B represent the scan lines of scans SC1 to SC9. FIG. 7B schematically shows the scan range in the pupil region AR1 obtained by the scans SC1 to SC9 of FIG. 7A. 8A and 8B represent scan lines of scans SC10 to SC16. For example, it is assumed that the eye E to be inspected moves diagonally upward from the completion of the scan SC9 to the start of the scan SC10. FIG. 8B schematically shows the scan range in the pupil region AR1 obtained by the scans SC10 to SC16 of FIG. 8A.

Scans SC1 to SC9 are executed in a state where the scan center position C substantially coincides with the alignment reference position AL (that is, the characteristic position of the eye E to be inspected). In the scans SC1 to SC9, data corresponding to the scan line passing through the alignment reference position AL (that is, the pupil center position) is acquired.

On the other hand, as shown in FIG. 8A, the scans SC10 to SC16 are executed centering on the scan center position C which is moved diagonally downward with respect to the alignment reference position AL. That is, in the scans SC10 to SC16, the scan center position C apparently moves with respect to the alignment reference position AL, and data corresponding to the scan line that does not pass through the alignment reference position AL is acquired.

As a result, even though the scan was started radially intersecting at the alignment reference position AL of the eye E to be inspected, the data of the scan line whose scan position deviated from the alignment reference position AL (pupil center position) was acquired. NS. Based on the data acquired assuming that the eye E to be inspected did not move, an accurate characteristic distribution cannot be obtained even if the shape, thickness, etc. of the cornea in the anterior eye portion Ea are obtained as shown in FIG. 9A.

Therefore, the analysis unit 141 according to the embodiment performs a process for correcting the position shift of the scan position from the scan result itself when the eye to be inspected moves due to fixation fine movement, line-of-sight shift, or the like during the radial scan. As an example of the configuration for executing such a position shift correction process of the scan position, the analysis unit 141 is provided with a scan identification unit 1412, a shape correction unit 1413, and a position correction unit 1414.

<< Scan Specific Unit 1412 >>
The scan identification unit 1412 identifies the scan performed on the characteristic region (pupil region) of the anterior eye portion Ea based on the detection result of the interference light obtained by the interference optical system 30. Specifically, the scan identification unit 1412 specifies the scan range in the B scan direction of the scan executed on the feature area.

The scan identification unit 1412 can specify the scan range by analyzing the tomographic image of the anterior eye portion Ea formed by the image forming unit 13 based on the detection result of the interference light. For example, the scan identification unit 1412 specifies the pupil region in the tomographic image obtained by scanning the anterior eye portion Ea including the pupil region, and specifies the range within the pupil region as the scan range. Further, for example, the scan identification unit 1412 specifies the iris region in the tomographic image obtained by scanning the anterior eye portion Ea including the pupil region, and specifies the range between the irises as the scan range. The scan identification unit 1412 can also specify the length of the specified scan range in the B scan direction.

<< Shape correction unit 1413 >>
The shape correction unit 1413 corrects the contour shape of the feature region specified by the feature region analysis unit 1411 from the front eye portion image of the eye E to be inspected acquired by the anterior eye portion camera 60. The characteristic region includes a region corresponding to the pupil (pupil region), a region corresponding to the cornea (cornea region), a region corresponding to the iris (iris region), and the like. The shape correction unit 1413 corrects the contour shape of the feature region based on the relative position of the anterior eye portion camera 60 with respect to the eye E to be inspected. Since the shape correction unit 1413 knows the relative position of the anterior eye portion camera 60 with respect to the eye E to be inspected, it is possible to correct the contour shape of the feature region by a known distortion correction process using this known information. .. When the eye E to be inspected is photographed from the front by correcting the contour shape of the characteristic region in the anterior segment image obtained by the anterior segment camera 60 arranged at a position off the optical axis of the interference optical system 30. It is possible to obtain an image in which a feature region having the same shape as is depicted.

The scan position of the scan result obtained by scanning the feature area may also be corrected by the shape correction unit 1413 using the parameter for correcting the contour shape of the feature area. Further, if necessary, it is not necessary to correct the contour shape of the feature region in the anterior eye portion image obtained by the anterior eye portion camera 60.

<< Position correction unit 1414 >>
The position correction unit 1414 corrects the positional deviation of the scan center position C of the radial scan based on the contour shape of the feature region. The contour shape may be a contour shape corrected by the shape correction unit 1413.

The position correction unit 1414 can correct the positional deviation of the scan center position C so that the scan range specified by the scan identification unit 1412 fits in the feature area. For example, the position correction unit 1414 corrects the misalignment of the scan center position C so that both ends of the scan range of at least two scans among the plurality of scans executed by the radial scan are arranged at the boundary of the feature area. be able to. Further, the position correction unit 1414 may correct the misalignment of the scan center position C so that at least the end side of the scan range corresponding to the lower eyelid side of the eye E to be inspected is arranged at the boundary of the feature area. As a result, even when the measurement light is eclipsed by the eyelashes or the eyelids, at least the data on the lower eyelid side in the feature region can be accurately acquired.

Further, the scan identification unit 1412 specifies the length of the scan range in the feature area of each scan, and the scan angle of the scan with reference to the vertical direction is known. Therefore, the position correction unit 1414 can correct the positional deviation of the scan center position C so that each scan range fits in the feature area from the length of the scan range and the scan angle.

Further, the position correction unit 1414 corrects the scan center position C so that the error between the polygon connecting both ends of the scan range of the plurality of scans executed by the radial scan with a straight line and the contour shape of the pupil region is minimized. can do.

FIG. 10 shows an operation explanatory view of the position correction unit 1414. In FIG. 10, the same parts as those in FIGS. 7A to 9A are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The position correction unit 1414 identifies the scan range in the pupil region AR1 for each scan, corrects the scan center position as described above, and acquires the scan result corresponding to the scan line as shown in FIG. Can be done. That is, the displacement of the scan center position C1 after the movement of the eye E to be examined is corrected with respect to the scan center position C0 before the movement of the eye E to be examined. As a result, the scan results of the scans SC1 to SC9 centered on the scan center position C0 before the movement of the eye E to be examined and the scan results of the scans SC10 to SC16 centered on the scan center position C1 after the movement of the eye E to be examined. Can be used to accurately acquire the data in the pupil region AR1.

By correcting the misalignment of the scan center position with the position correction unit 1414 as described above, even if the eye E to be inspected moves during the radial scan, the data in the feature area can be accurately acquired using only the scan result. be able to.

The analysis unit 141 is calculated by the characteristic information calculation unit 1415 and the characteristic information calculation unit 1415 that calculate the characteristic information of the eye E to be inspected from the scan result of the scan range in which the misalignment of the scan center position is corrected as described above. The characteristic distribution calculation unit 1416 for obtaining the distribution of the characteristic information is included.

<< Characteristic information calculation unit 1415 >>
The characteristic information calculation unit 1415 calculates the characteristic information of the anterior eye portion Ea based on the detection result of the interference light corresponding to the scan range of the scan in which the positional deviation of the scan center position is corrected by the position correction unit 1414. The characteristic information includes at least one of corneal shape information, corneal thickness information, and anterior chamber depth information. For example, the characteristic information calculation unit 1415 uses a known method using the detection result of the interference light corresponding to the scan range of the scan in which the misalignment of the scan center position is corrected, and the shape of the corneal surface, the shape of the corneal back surface, and the corneal thickness. Ask for.

<< Characteristic distribution calculation unit 1416 >>
The characteristic distribution calculation unit 1416 obtains the distribution of the characteristic information calculated by the characteristic information calculation unit 1415. The characteristic distribution calculation unit 1416 associates the obtained information representing the shape of the corneal surface with the x-coordinate position and the y-coordinate position to generate information representing a two-dimensional distribution. Further, the characteristic distribution calculation unit 1416 may generate information representing a three-dimensional distribution by associating information indicating the shape of the corneal surface with the x-coordinate position, the y-coordinate position, and the z-coordinate position.

Further, the characteristic distribution calculation unit 1416 obtains the shape of the corneal surface, the shape of the back surface of the cornea, and the corneal film thickness by a known method using the detection result of the interference light, and then obtains information indicating the shape of the obtained corneal surface and the like. On the other hand, the misalignment of the scan center position may be corrected to generate information representing a two-dimensional distribution. Similarly, the characteristic distribution calculation unit 1416 may generate information representing a three-dimensional distribution by correcting the positional deviation with respect to the obtained information representing the shape of the corneal surface and the like.

The data processing unit 14 that functions as described above includes, for example, the above-mentioned processor, RAM, ROM, hard disk drive, circuit board, and the like. A computer program that causes a processor to execute the above functions is stored in a storage device such as a hard disk drive in advance.

The region corresponding to the pupil in the eye E to be inspected (pupil region) is an example of the "characteristic region" according to the embodiment. The direction orthogonal to the traveling direction of the measurement light or the B-scan direction is an example of the "intersection direction" according to the embodiment. The scan identification unit 1412 is an example of the “scan range identification unit” according to the embodiment. The position correction unit 1414 is an example of the “correction unit” according to the embodiment. At least one of the first drive mechanism 80A and the second drive mechanism 80B is an example of the "moving mechanism" according to the embodiment. The anterior segment camera 60 is an example of the “anterior segment imaging system” according to the embodiment. The feature area analysis unit 1411 is an example of the "specific unit" according to the embodiment.

[motion]
The operation of the ophthalmic apparatus 1 will be described.

FIG. 11 shows a flow chart of an operation example of the ophthalmic apparatus 1.

(Step S1)
When the user instructs the user interface unit 90 to start OCT measurement, the ophthalmic apparatus 1 starts alignment. The alignment start instruction may be automatically given by the control unit 11.

When the alignment start instruction is given, the control unit 11 starts photographing the anterior eye portion Ea by the anterior eye portion cameras 60A and 60B, respectively. This shooting is a moving image shooting in which the anterior eye portion Ea is the shooting target. Each anterior eye camera 60A and 60B shoots a moving image at a predetermined frame rate. Here, the imaging timings of the front eye camera 60A and 60B may be synchronized by the control unit 11. The front eye cameras 60A and 60B sequentially send the acquired frames to the control unit 11 in real time. The control unit 11 associates the frames obtained by both front eye cameras 60A and 60B with each other according to the shooting timing. That is, the control unit 11 associates frames acquired substantially at the same time by both front eye camera 60A and 60B. This association is executed, for example, based on the above-mentioned synchronization control or based on the input timing of the frame from the anterior eye camera 60A and 60B. The control unit 11 sends the associated pair of frames to the analysis unit 141. The analysis unit 141 analyzes each frame.

In the case of auto-alignment, the feature region analysis unit 1411 analyzes each frame and executes a process for identifying a pupil region corresponding to the pupil of the anterior segment Ea in the anterior segment image acquired in step S1. .. The feature area analysis unit 1411 specifies the pupil region as described above, and specifies the pupil center position in the specified pupil region as the feature position. Subsequently, the control unit 11 causes the analysis unit 141 to specify the amount of misalignment and the direction of misalignment between the position corresponding to the optical axis of the optical system 20 and the center position of the pupil. Further, the control unit 11 relatively controls the optical system 20 and the eye E to be inspected by controlling at least one of the first drive mechanism 80A and the second drive mechanism 80B so that the specified displacement amount is cancelled. Move.

In the case of manual alignment, the control unit 11 controls at least one of the first drive mechanism 80A and the second drive mechanism 80B in response to the user's operation with respect to the user interface unit 90, thereby causing the optical system 20 and the eye to be inspected E. To move relatively. In this case, the user can perform the alignment by using the user interface unit 90 while referring to the displayed observation image. The user moves the optical system 20 relative to the eye E to be inspected by operating the user interface unit 90 so that the image of the pupil is reflected in the observation image.

(Step S2)
The control unit 11 determines whether or not the alignment of the optical system 20 with respect to the eye E to be inspected is completed. The control unit 11 determines whether or not the alignment of the optical system 20 with respect to the eye E to be inspected is completed by determining whether or not the amount of misalignment specified in step S1 is equal to or less than a predetermined threshold value. Is possible.

When it is determined that the alignment of the optical system 20 with respect to the eye E to be inspected is completed (step S2: Y), the operation of the ophthalmic apparatus 1 shifts to step S3. When it is not determined that the alignment of the optical system 20 with respect to the eye E to be inspected is completed (step S2: N), the operation of the ophthalmic apparatus 1 shifts to step S1.

(Step S3)
When it is determined in step S2 that the alignment of the optical system 20 with respect to the eye to be inspected E is completed (step S2: Y), the control unit 11 controls the anterior eye portion camera 60 to control the anterior eye portion of the eye to be inspected E. Get the image. In step S3, the anterior segment image acquired in step S2 may be used as it is.

(Step S4)
The control unit 11 causes the feature region analysis unit 1411 to specify the pupil region in the anterior eye portion image acquired in step S3.

(Step S5)
The control unit 11 causes the shape correction unit 1413 to correct the contour shape of the pupil region specified in step S4. The shape correction unit 1413 corrects the contour shape of the pupil region in the anterior eye portion image by performing a known arithmetic process corresponding to the relative position of the anterior eye portion camera 60 with respect to the eye E to be inspected.

(Step S6)
Next, the control unit 11 starts the OCT measurement by controlling the interference optical system 30.

(Step S7)
The control unit 11 controls the optical scanner 40 according to a predetermined scan pattern to start a radial scan on the anterior eye portion Ea of the eye E to be inspected. The control unit 11 executes each scan shown in FIG. 5 in order.

(Step S8)
The control unit 11 determines whether or not the scan is completed. The control unit 11 can determine whether or not the scan is completed based on a predetermined scan pattern. When it is determined that the scan is completed (step S8: Y), the operation of the ophthalmic apparatus 1 shifts to step S9. When it is determined that the scan is not completed (step S8: N), the operation of the ophthalmic apparatus 1 shifts to step S7.

(Step S9)
When it is determined in step S8 that the scan is completed (step S8: Y), the control unit 11 specifies the scan range for each scan executed in step S7 as described above, and shifts the position of the scan center position. Is corrected by the position correction unit 1414.

(Step S10)
Subsequently, the control unit 11 causes the characteristic information calculation unit 1415 to calculate the characteristic information based on the detection result of the interference light corresponding to the scan range of the scan in which the scan center position is corrected in step S9.

(Step S11)
The control unit 11 causes the characteristic distribution calculation unit 1416 to calculate the characteristic distribution information representing the distribution of the specific information calculated in step S10.

(Step S12)
The control unit 11 causes the display unit of the user interface unit 90 to display the characteristic distribution corresponding to the characteristic distribution information calculated in step S11. This completes the operation of the ophthalmic apparatus 1 (end).

As described above, according to the embodiment, even if the eye to be inspected moves due to fixation tremor, line-of-sight shift, etc. during the radial scan, the position of the scan center position of the radial scan with the pupil region as the scan range from the scan result itself. Since the deviation can be corrected, the data of the anterior segment can be accurately acquired (collected).

In the above embodiment, the case of collecting the data of the anterior segment Ea of the eye E to be inspected has been described, but the above embodiment can be similarly applied to the case of collecting the data of the fundus of the eye E to be inspected. can.

(Modification example)
In the above embodiment, the measurement light may be eclipsed by the eyelids, eyelashes, etc. during scanning. In the modified example of the embodiment, the scan center position C of the radial scan is arranged so that the end side of the scan range corresponding to the lower eyelid side of the eye E to be inspected is arranged at the boundary of the feature region when the measurement light is eclipsed. The misalignment is corrected. Hereinafter, a modified example of the embodiment will be described focusing on the differences from the embodiment.

The configuration of the ophthalmic apparatus according to this modification is substantially the same as the configuration of the ophthalmic apparatus 1 according to the embodiment. The configuration of the ophthalmic apparatus according to this example is different from the configuration of the ophthalmic apparatus 1 according to the embodiment in that the analysis unit 141a is provided instead of the analysis unit 141.

FIG. 12 shows a block diagram of a configuration example of the analysis unit 141a according to this modification. In FIG. 12, the same parts as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The difference between the analysis unit 141a and the analysis unit 141 is that the detection unit 1417 is provided. The detection unit 1417 detects the occurrence of eclipse of the measurement light. The detection unit 1417 can detect the presence or absence of eclipse of the measurement light from the detection result of the interference light obtained by the interference optical system 30. In this modification, when the detection unit 1417 detects the occurrence of eclipse of the measurement light, the position correction unit 1414 corrects the positional deviation of the scan center position as described above. The position correction unit 1414 can correct the misalignment of the scan center position so that the end side of the scan range corresponding to the lower eyelid side of the eye E to be inspected is arranged at the boundary of the pupil region.

FIG. 13A schematically shows a scan line when the measurement light is eclipsed by the eyelid of the eye E to be inspected in this modified example. FIG. 13A schematically shows a scan line when the eye E to be inspected moves diagonally upward between the time when the executions of the scans SC1 to SC9 are completed and the time when the scan SC10 is killed. In FIG. 13A, the same parts as those in FIG. 7A or FIG. 8A are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

When the measurement light is eclipsed by the eyelid MB1 of the eye E to be inspected, it becomes impossible to scan the upper eyelid side of the scanning range depending on the scanning angle. On the other hand, it is possible to scan the lower eyelid side of the scan range for scans SC1 to SC16. Therefore, as described above, the position correction unit 1414 corrects the misalignment of the scan center position so that the end side of the scan range corresponding to the lower eyelid side of the eye E to be inspected is arranged at the boundary of the pupil region. As a result, as shown in FIG. 13B, even when the measurement light is eclipsed by the eyelid MB1, data can be accurately acquired for at least a part of the pupil region AR1.

Therefore, when the scan center position when the scans SC1 to SC9 are executed and the scan center position when the scans SC10 to SC16 are executed are aligned as shown in FIG. 14, the shape of the cornea in the anterior eye portion Ea and the shape of the cornea It is not possible to accurately determine the thickness and the like. On the other hand, in this modification, the misalignment of the scan center position is corrected so that at least the end side of the scan range corresponding to the lower eyelid side of the eye E to be inspected is arranged at the boundary of the pupil region. , The shape and thickness of the cornea in the anterior segment Ea can be accurately determined by using the scan results corresponding to the scan lines as shown in FIG.

[effect]
The effect of the ophthalmic apparatus according to the embodiment will be described.

The ophthalmic apparatus (1) according to the embodiment includes an optical scanner (40), an interference optical system (30), a control unit (11), a scan range identification unit (scan identification unit 1412), and a position correction unit (1414). ) And the specific information calculation unit (1415). The interfering optical system divides the light from the light source into the measurement light and the reference light, projects the measurement light onto the eye to be inspected (E) via an optical scanner, and combines the return light and the reference light of the measurement light from the eye to be inspected. Detects interference light. The control unit uses an optical scanner to perform a radial scan that performs a plurality of radial scans centered on the reference position in the anterior segment of the eye with respect to the characteristic region (pupil region AR1) in the anterior segment (Ea) of the eye to be inspected. Control. The scan range specifying unit specifies a scan range in the crossing direction (B scan direction) that intersects the traveling direction of the measurement light in the feature region based on the detection result of the interference light. The correction unit corrects the misalignment of the scan center position (C) of the radial scan based on the contour shape of the feature area. The characteristic information calculation unit calculates the characteristic information of the anterior eye portion based on the detection result of the interference light corresponding to the scan range of the scan in which the misalignment of the scan center position is corrected by the correction unit.

According to such a configuration, for a plurality of scans executed by the radial scan, the misalignment of the scan center position is corrected based on the contour shape of the feature area, and the scan range of the scan in which the misalignment is corrected is supported. Since the characteristic information of the anterior segment is calculated based on the detection result of the interference light, the difference between the image acquisition timing and the scan timing even if the eye to be examined moves due to fixation fine movement or line-of-sight shift during scanning. It becomes possible to accurately acquire the data of the anterior segment of the eye without being affected by the error caused by the above.

Further, in the ophthalmic apparatus according to the embodiment, the correction unit may correct the misalignment so that the scan range falls within the feature area.

According to such a configuration, the displacement of the scan center position can be easily corrected only by the scan result.

Further, in the ophthalmic apparatus according to the embodiment, the correction unit may correct the misalignment based on the length of the scan range and the scan angle of the scan with respect to the reference direction.

According to such a configuration, it is possible to correct the misalignment of the scan center position by a simple process based on the scan range and the scan angle.

Further, in the ophthalmic apparatus according to the embodiment, the correction unit may correct the misalignment so that the end side of the scan range corresponding to the lower eyelid side of the eye to be inspected is arranged at the boundary of the feature region.

According to such a configuration, even if the measurement light is eclipsed by the eyelids, eyelashes, or the like, data can be accurately acquired for at least a part of the feature region.

Further, the ophthalmic apparatus according to the embodiment includes a detection unit (1417) for detecting the occurrence of eclipse of the measurement light, and the correction unit may correct the misalignment when the occurrence of eclipse is detected by the detection unit. good.

According to such a configuration, the misalignment is corrected so that the end side of the scan range corresponding to the lower eyelid side of the eye to be inspected is arranged at the boundary of the feature area when the measurement light is eclipsed. Therefore, the data of the anterior segment can be accurately acquired regardless of the presence or absence of eclipse of the measurement light.

Further, the ophthalmic apparatus according to the embodiment includes an anterior segment imaging system (anterior segment camera 60) for photographing the anterior segment of the eye to be inspected and an anterior segment image acquired by using the anterior segment imaging system. A specific unit (feature area analysis unit 1411) that specifies the feature area in the above may be included.

According to such a configuration, it becomes possible to provide an ophthalmic apparatus capable of accurately acquiring data by following a change in the shape of a feature region such as a change in the pupil diameter.

Further, the ophthalmic apparatus according to the embodiment may include a shape correction unit (1413) that corrects the contour shape of the feature region based on the relative position of the anterior ocular segment imaging system with respect to the eye to be inspected.

According to such a configuration, it is possible to obtain an image in which a feature region having a shape similar to that when the eye to be inspected is photographed from the front is depicted.

Further, the ophthalmic apparatus according to the embodiment includes an image forming portion (13) that forms a tomographic image of the eye to be inspected based on the detection result of the interference light, and the scanning range specifying portion is a tomographic image formed by the image forming portion. The scan range may be specified based on.

According to such a configuration, since the scan range is specified by analyzing the tomographic image, the displacement of the scan center position can be corrected by a simple process.

Further, the ophthalmic apparatus according to the embodiment may include a characteristic distribution calculation unit (1416) for obtaining a distribution of characteristic information of the anterior eye portion calculated by the characteristic information calculation unit.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of obtaining a distribution of characteristic information that accurately reflects the data of the anterior eye portion.

Further, in the ophthalmic apparatus according to the embodiment, the characteristic information may include at least one of corneal shape information, corneal film thickness information, and anterior chamber depth information.

According to such a configuration, even if the eye to be inspected moves due to fixation tremor or line-of-sight shift during scanning, corneal shape information, corneal film thickness information, anterior chamber depth information, etc. can be accurately obtained. ..

Further, the ophthalmic device according to the embodiment includes a moving mechanism (first drive mechanism 80A, second drive mechanism 80B) that relatively moves the eye to be inspected and the interference optical system, and the reference position is the interference with the eye to be inspected. It may be the alignment reference position of the optical system.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of accurately acquiring data of the anterior segment of the eye to be inspected in consideration of the positional deviation of the scan position with respect to the alignment reference position. Become.

Further, in the ophthalmic apparatus according to the embodiment, the reference position may be the pupil center position, the pupil center of gravity position, the cornea center position, the cornea apex position, or the eye center position to be inspected.

According to such a configuration, the data of the anterior segment can be accurately acquired in consideration of the positional deviation of the scan position with respect to the pupil center position, the pupil center of gravity position, the cornea center position, the cornea apex position or the eye center position to be inspected. It will be possible to provide an ophthalmic device capable of providing an ophthalmic device.

Further, in the ophthalmic apparatus according to the embodiment, the characteristic region may be a region corresponding to the pupil, cornea, or iris of the eye to be inspected.

According to such a configuration, it is possible to provide an ophthalmic apparatus capable of accurately acquiring data of a pupil region, a corneal region, or an iris region.

A computer program for realizing the above embodiment can be stored in any computer-readable recording medium. Examples of the recording medium include semiconductor memory, optical disc, magneto-optical disk (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), magnetic storage medium (hard disk / floppy (registered trademark) disk / ZIP, etc.) and the like. Can be used.

It is also possible to send and receive this program through a network such as the Internet or LAN.

1 Ophthalmology device 10 Processor 11 Control unit 12 Storage unit 13 Image formation unit 14 Data processing unit 20 Optical system 30 Interference optical system 40 Optical scanner 50 Objective lens 51 Front lens 60 Front eye camera 70 Face support 80A First drive mechanism 80B Second drive mechanism 90 User interface unit 141, 141a Analysis unit 1411 Feature area analysis unit 1412 Scan identification unit 1413 Shape correction unit 1414 Position correction unit 1415 Characteristic information calculation unit 1416 Characteristic distribution calculation unit 1417 Detection unit E Eye to be inspected Ea Front eye Department

Claims (11)

With an optical scanner
The light from the light source is divided into a measurement light and a reference light, the measurement light is projected onto the eye to be inspected via the optical scanner, and the return light of the measurement light from the eye to be inspected and the interference light of the reference light. Interference optical system to detect
A control unit that controls the optical scanner to perform a radial scan that performs a plurality of scans radially around a reference position in the anterior eye portion with respect to a characteristic region in the anterior segment of the eye to be inspected.
Based on the detection result of the interference light, a scan range specifying unit that specifies a scan range in the crossing direction that intersects the traveling direction of the measurement light in the feature region, and a scan range specifying unit.
A correction unit that corrects the displacement of the scan center position of the radial scan so that the scan range fits within the feature area based on the contour shape of the feature area.
A characteristic information calculation unit that calculates characteristic information of the anterior eye portion based on the detection result of interference light corresponding to the scan range of the scan in which the displacement of the scan center position is corrected by the correction unit.
Only including,
The correction unit is an ophthalmic apparatus that corrects the misalignment so that the end side of the scan range corresponding to the lower eyelid side of the eye to be inspected is arranged at the boundary of the feature region. The ophthalmic apparatus according to claim 1, wherein the correction unit corrects the positional deviation based on the length of the scan range and the scan angle of the scan with respect to the reference direction. Includes a detector that detects the occurrence of eclipse of the measurement light.
The ophthalmic apparatus according to claim 1 or 2, wherein the correction unit corrects the misalignment when the detection unit detects the occurrence of the eclipse. An anterior segment imaging system for photographing the anterior segment of the eye to be inspected,
A specific portion that specifies the characteristic region in the anterior segment image acquired by using the anterior segment imaging system, and a specific portion that specifies the characteristic region.
The ophthalmic apparatus according to any one of claims 1 to 3, wherein the ophthalmic apparatus comprises. The ophthalmologic apparatus according to claim 4, further comprising a shape correction unit that corrects the contour shape of the feature region based on the relative position of the anterior eye portion photographing system with respect to the eye to be inspected. It includes an image forming portion that forms a tomographic image of the eye to be inspected based on the detection result of the interference light.
The ophthalmic apparatus according to any one of claims 1 to 5, wherein the scan range specifying unit specifies the scan range based on a tomographic image formed by the image forming unit. The ophthalmic apparatus according to any one of claims 1 to 6, wherein the ophthalmic apparatus includes a characteristic distribution calculation unit for obtaining a distribution of characteristic information of the anterior eye portion calculated by the characteristic information calculation unit. The ophthalmic apparatus according to any one of claims 1 to 7, wherein the characteristic information includes at least one of corneal shape information, corneal film thickness information, and anterior chamber depth information. It includes a moving mechanism that relatively moves the eye to be inspected and the interferometric optical system.
The ophthalmic apparatus according to any one of claims 1 to 8, wherein the reference position is an alignment reference position of the interference optical system with respect to the eye to be inspected. The ophthalmic apparatus according to any one of claims 1 to 9, wherein the reference position is a pupil center position, a pupil center of gravity position, a cornea center position, a cornea apex position, or an eye test center position. The ophthalmic apparatus according to any one of claims 1 to 10, wherein the characteristic region is a region corresponding to the pupil, cornea, or iris of the eye to be inspected.

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