JP2018126256A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for the alignment of an ophthalmologic apparatus.SOLUTION: An ophthalmologic apparatus includes an optical system for collecting data by scanning a region including at least part of the front of the face of a subject using optical coherence tomography, a driving part for relatively moving an eye to be examined and the optical system in an optical axis direction of the optical system, an analysis part for specifying a first position corresponding to at least the part of the region based on the data collected by the optical system, and a control part for relatively moving the eye to be examined and the optical system by controlling the driving part based on the first position specified by the analysis part.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an ophthalmic apparatus.

  The ophthalmologic apparatus includes an ophthalmologic photographing apparatus for obtaining an image of the eye to be examined and an ophthalmologic measuring apparatus for measuring the characteristics of the eye to be examined.

  As an example of an ophthalmologic photographing apparatus, an optical coherence tomography (Optical Coherence Tomography, OCT) is used to obtain a tomographic image, a fundus camera for photographing the fundus, and a fundus image obtained by laser scanning using a confocal optical system. There is a scanning laser opthalmoscope (SLO).

  Examples of ophthalmic measuring devices include an ocular refraction examination device (refractometer, keratometer) that measures the refractive characteristics of the eye to be examined, a tonometer, a specular microscope that obtains corneal properties (corneal thickness, cell distribution, etc.), Hartmann There is a wave front analyzer that obtains aberration information of the eye to be examined using a shack sensor.

  In ophthalmic examination, alignment between the apparatus optical system and the eye to be examined is extremely important from the viewpoint of accuracy and accuracy of examination. This alignment is called alignment. The alignment includes an operation for aligning the optical axis of the apparatus optical system with the axis of the eye to be examined (XY alignment) and an operation for adjusting the distance between the eye to be examined and the apparatus optical system to a predetermined distance (Z alignment). included.

  There are various methods for alignment. As a typical technique, a technique is known in which light is projected onto the cornea and a reflected image (Purkinje image) is detected for alignment (see, for example, Patent Document 1).

  Further, as a technique realized in recent years, two or more photographed images obtained by photographing the anterior segment from different directions are analyzed to identify the three-dimensional position of the eye to be examined, and XY alignment is performed based on the three-dimensional position. There is a method for performing both of the Z alignment and the Z alignment (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-024019 JP 2013-248376 A

  In such a conventional alignment method, it is necessary to provide an optical system for alignment in the ophthalmic apparatus. However, the ophthalmologic apparatus is required to be highly simplified while simplifying the configuration. In particular, miniaturization of optical systems is required for portable ophthalmic devices.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a new technique for alignment of ophthalmic apparatuses.

The first aspect of the ophthalmologic apparatus according to the embodiment includes an optical system for collecting data by scanning an area including at least a part of the front surface of the subject's face using optical coherence tomography, and the optical A first position corresponding to at least a part of the region is identified based on a drive unit that relatively moves the eye to be examined and the optical system in the optical axis direction of the system, and the data collected by the optical system And a control unit that controls the drive unit based on the first position specified by the analysis unit to move the eye to be examined and the optical system relative to each other.
In the second aspect of the ophthalmologic apparatus according to the embodiment, in the first aspect, the optical system divides light from the objective lens and the light source into reference light and measurement light, and the measurement light passes through the objective lens. An interference optical system that detects interference light between the return light of the measurement light from the eye to be examined and the reference light, and the analysis unit is detected by the interference optical system. The first position is specified based on the detection result of the interference light, and the control unit includes the position of the objective lens, the first position, the optical path length of the reference light, and the optical path length of the measurement light. The eye to be examined and the optical system are relatively moved based on the second position where the two coincide with each other.
In a third aspect of the ophthalmologic apparatus according to the embodiment, in the second aspect, the control unit includes a first distance between the position of the objective lens and the second position, and the detection result of the interference light. The eye to be examined and the optical system are relatively moved based on a second distance between a position corresponding to two positions and the first position.
In a fourth aspect of the ophthalmologic apparatus according to the embodiment, in the third aspect, the control unit includes the eye to be examined and the optical system so that a sum of the first distance and the second distance becomes a predetermined working distance. And move relative to each other.
In the fifth aspect of the ophthalmologic apparatus according to the embodiment, in the third aspect or the fourth aspect, the interference optical system changes the optical path length that relatively changes the optical path length of the reference light and the optical path length of the measurement light. A distance specifying unit that specifies the first distance based on an optical path length difference between the optical path of the reference light and the optical path of the measurement light, which is changed by the optical path length changing unit.
In a sixth aspect of the ophthalmologic apparatus according to the embodiment, in the fifth aspect, the optical path length changing unit is arranged in the optical path of the reference light or the optical path of the measurement light, and a corner cube movable along the optical path is used. Including.
In a seventh aspect of the ophthalmologic apparatus according to the embodiment, in the fifth aspect or the sixth aspect, the apparatus includes a storage unit that stores in advance correspondence information in which the information corresponding to the optical path length difference is associated with the first distance, The distance specifying unit specifies the first distance based on the correspondence information stored in the storage unit.
In an eighth aspect of the ophthalmologic apparatus according to the embodiment, in any one of the first aspect to the seventh aspect, an imaging unit that images at least a part of the region is included, and the driving unit is in the optical axis direction of the optical system The eye to be examined and the optical system are relatively moved in a direction that intersects with the optical system, and the control unit is configured to intersect the optical axis direction of the optical system based on a photographed image obtained by the photographing unit. After relatively moving the eye to be examined and the optical system, the eye to be examined and the optical system are relatively moved in the optical axis direction based on the first position.
In a ninth aspect of the ophthalmologic apparatus according to the embodiment, in any one of the first aspect to the eighth aspect, the support unit supports the face, and the drive unit relatively connects the support unit and the optical system. Move to.
In a tenth aspect of the ophthalmic apparatus according to the embodiment, in any one of the first to ninth aspects, the optical system scans an area including the cornea, the eyelid, the nose, or the cheek.
In addition, it is possible to combine arbitrarily the structure which concerns on the above-mentioned several claim.

It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is the schematic for demonstrating the process which the ophthalmologic apparatus which concerns on embodiment performs. It is a schematic block diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a flowchart showing the operation example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation example of the ophthalmologic apparatus which concerns on embodiment. It is a flowchart showing the operation example of the ophthalmologic apparatus which concerns on embodiment. It is a flowchart showing the operation example of the ophthalmologic apparatus which concerns on embodiment.

  An example of an embodiment of an ophthalmologic apparatus according to the present invention will be described in detail with reference to the drawings. In addition, it is possible to use the description content of the literature referred in this specification, and arbitrary well-known techniques for the following embodiment.

  The ophthalmologic apparatus according to the embodiment has a function of an optical coherence tomography using OCT, and is used for optical examination of an eye to be examined. Such an ophthalmologic apparatus includes an ophthalmologic photographing apparatus having an optical coherence tomography function and an ophthalmic measurement apparatus. Examples of the ophthalmologic photographing apparatus include a fundus camera, a scanning laser ophthalmoscope, and a slit lamp in addition to the optical coherence tomography. In addition, examples of the ophthalmologic measurement apparatus include an eye refraction inspection apparatus, a tonometer, a specular microscope, and a wave front analyzer. In the following embodiments, an ophthalmologic apparatus having the function of an optical coherence tomography and the function of a fundus camera will be described as an example. However, the ophthalmologic apparatus having only the function of the optical coherence tomography and the function of the optical coherence tomography and any function other than the fundus camera (any function of the ophthalmologic photographing apparatus and ophthalmic measurement apparatus) The invention can be applied.

  In this specification, information (signal) acquired by OCT may be collectively referred to as OCT information (OCT signal), and images acquired by OCT may be collectively referred to as OCT images. In addition, a measurement operation for forming an OCT image may be referred to as OCT measurement. An optical system housed in an ophthalmic apparatus may be referred to as an apparatus optical system. In addition, it is possible to use suitably the description content of the literature described in this specification as the content of the following embodiment.

  Further, in the following embodiments, an optical coherence tomography using a so-called “swept source” type OCT equipped with a wavelength-swept light source and a balanced photodiode will be described. However, the present invention can also be applied to optical coherence tomography using an OCT technique other than a swept source, for example, a spectral domain type or an infarth type. Spectral domain OCT means that the light from a low-coherence light source is divided into measurement light and reference light, and the return light of the measurement light from the test object is made to interfere with the reference light to generate interference light. In this method, the spectral distribution of light is detected by a spectroscope, and the detected spectral distribution is subjected to Fourier transform or the like to form an image. Further, in-face OCT is to irradiate the object to be measured with light having a predetermined beam diameter and analyze the component of the interference light obtained by superimposing the reflected light and the reference light. This is a technique for forming an image of an object to be measured in a cross section perpendicular to the traveling direction of light, and is also called a full-field type.

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

[Constitution]
The ophthalmologic apparatus 1 according to the embodiment houses an optical system (apparatus optical system) for inspecting an eye to be examined. As shown in FIGS. 1A and 1B, the ophthalmologic apparatus 1 includes a base 410, a housing 420 provided on the base 410, and a lens housing that can move three-dimensionally (in the xyz direction) relative to the base 410. Part 430. The base 410 stores a drive system such as an optical system drive unit, which will be described later, and an arithmetic control circuit. The housing 420 stores the above optical system. The lens housing portion 430 is provided so as to protrude from the front surface of the housing 420 and houses an objective lens 22 described later. Note that the lens housing portion 430 illustrated in FIGS. 1A and 2A may be provided so as not to protrude from the front surface of the housing 420. At least one of the housing 420 and the lens housing portion 430 may be configured to be movable with respect to the base 410.

  The ophthalmologic apparatus 1 is provided with a chin rest and a forehead pad that are fixed to the base 410 and support the face of the subject. The chin rest and the forehead support correspond to the support portion 440 shown in FIGS. 1A and 1B.

  As shown in FIG. 2, the ophthalmologic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The retinal camera unit 2 has almost the same optical system as a conventional retinal camera. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the fundus. The arithmetic control unit 200 includes a computer that executes various arithmetic processes and control processes.

[Fundus camera unit]
The fundus camera unit 2 shown in FIG. 2 is provided with an optical system for acquiring a two-dimensional image (fundus image) representing the surface form of the fundus oculi Ef of the eye E to be examined. The fundus image includes an observation image and a captured image. The observation image is, for example, a monochrome moving image formed at a predetermined frame rate using near infrared light. When the optical system is focused on the anterior segment of the eye E, the fundus camera unit 2 can acquire an observation image of the anterior segment. The captured image may be, for example, a color image obtained by flashing visible light, or a monochrome still image using near infrared light or visible light as illumination light. The fundus camera unit 2 may be configured to be able to acquire images other than these, for example, a fluorescein fluorescent image, an indocyanine green fluorescent image, a spontaneous fluorescent image, and the like.

  The fundus camera unit 2 is provided with an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the fundus oculi Ef with illumination light. The photographing optical system 30 guides the fundus reflection light of the illumination light to an imaging device (CCD image sensor (sometimes simply referred to as a CCD) 35, 38). In addition, the imaging optical system 30 guides the measurement light from the OCT unit 100 to the eye E (fundus Ef or anterior eye portion) and guides the measurement light passing through the eye E to the OCT unit 100.

  The observation light source 11 of the illumination optical system 10 is composed of, for example, a halogen lamp. The light (observation illumination light) output from the observation light source 11 is reflected by the reflection mirror 12 having a curved reflection surface, passes through the condensing lens 13, passes through the visible cut filter 14, and is converted into near infrared light. Become. Further, the observation illumination light is once converged in the vicinity of the photographing light source 15, reflected by the mirror 16, and passes through the relay lenses 17 and 18, the diaphragm 19 and the relay lens 20. Then, the observation illumination light is reflected at the peripheral portion (region around the hole portion) of the aperture mirror 21, passes through the dichroic mirror 46, and is refracted by the objective lens 22 to illuminate the fundus oculi Ef. An LED (Light Emitting Diode) can also be used as the observation light source.

  The fundus reflection light of the observation illumination light is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the center region of the perforated mirror 21, passes through the dichroic mirror 55, and is focused. The light is reflected by the mirror 32 via the lens 31. Further, the fundus reflection light passes through the half mirror 39A, is reflected by the dichroic mirror 33, and forms an image on the light receiving surface of the CCD image sensor 35 by the condenser lens. The CCD image sensor 35 detects fundus reflected light at a predetermined frame rate, for example. On the display device 3, an image (observation image) based on fundus reflection light detected by the CCD image sensor 35 is displayed. When the photographing optical system 30 is focused on the anterior segment, an observation image of the anterior segment of the eye E is displayed.

  The imaging light source 15 is constituted by, for example, a xenon lamp. The light (imaging illumination light) output from the imaging light source 15 is applied to the fundus oculi Ef through the same path as the observation illumination light. The fundus reflection light of the imaging illumination light is guided to the dichroic mirror 33 through the same path as that of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is reflected by the condenser lens 37 of the CCD image sensor 38. An image is formed on the light receiving surface. On the display device 3, an image (captured image) based on fundus reflection light detected by the CCD image sensor 38 is displayed. Note that the display device 3 that displays the observation image and the display device 3 that displays the captured image may be the same or different. In addition, when similar imaging is performed by illuminating the eye E with infrared light, an infrared captured image is displayed. It is also possible to use an LED as a photographing light source.

  An LCD (Liquid Crystal Display) 39 displays a fixation target and an eyesight measurement index. The fixation target is an index for fixing the eye E to be examined, and is used at the time of fundus photographing or OCT measurement.

  A part of the light output from the LCD 39 is reflected by the half mirror 39 </ b> A, reflected by the mirror 32, passes through the hole of the perforated mirror 21 through the photographing focusing lens 31 and the dichroic mirror 55. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus oculi Ef.

  By changing the display position of the fixation target on the screen of the LCD 39, the fixation position of the eye E can be changed. The fixation position of the eye E includes, for example, a position for acquiring an image similar to that of a conventional fundus camera. Examples of such an image include an image centered on the macular portion of the fundus oculi Ef, an image centered on the optic disc, and an image centered on the fundus center between the macula portion and the optic disc. It is also possible to arbitrarily change the display position of the fixation target.

  Further, the fundus camera unit 2 is provided with a focus optical system 60 as in the conventional fundus camera. The alignment optical system 50 generates an index (alignment index) for performing alignment (alignment) of the apparatus optical system with respect to the eye E. The focus optical system 60 generates an index (split index) for focusing on the fundus oculi Ef.

  The light (alignment light) output from the LED 51 of the alignment optical system 50 is reflected by the dichroic mirror 55 via the apertures 52 and 53 and the relay lens 54, and passes through the hole portion of the perforated mirror 21. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46 and is projected onto the cornea of the eye E by the objective lens 22.

  The cornea-reflected light of the alignment light passes through the objective lens 22, the dichroic mirror 46, and the hole, part of which passes through the dichroic mirror 55, passes through the photographing focusing lens 31, is reflected by the mirror 32, and is half The light passes through the mirror 39A. The light transmitted through the half mirror 39 </ b> A is reflected by the dichroic mirror 33 and projected onto the light receiving surface of the CCD image sensor 35 by the condenser lens 34. The light reception image (alignment index) by the CCD image sensor 35 is displayed on the display device 3 together with the observation image. The user performs alignment by performing the same operation as that of a conventional fundus camera. Further, the arithmetic control unit 200 may perform alignment by analyzing the position of the alignment index and moving the optical system (auto-alignment function). In this embodiment, since auto-alignment can be executed using OCT information as will be described later, it is not an essential matter that auto-alignment using an alignment index is possible. However, it is possible to configure so that the auto alignment using the alignment index can be performed when the auto alignment using the OCT information is not successful. Moreover, you may comprise so that the auto alignment using an OCT information and the auto alignment using an alignment parameter | index can be used selectively.

  When performing the focus adjustment, the reflecting surface of the reflecting rod 67 is obliquely provided on the optical path of the illumination optical system 10. The light (focus light) output from the LED 61 of the focus optical system 60 passes through the relay lens 62, is separated into two light beams by the split indicator plate 63, and passes through the two-hole aperture 64. The light that has passed through the two-hole aperture 64 is reflected by the mirror 65, and once formed on the reflecting surface of the reflecting bar 67 by the condenser lens 66 and reflected. Further, the focus light passes through the relay lens 20, is reflected by the perforated mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus oculi Ef.

  The fundus reflection light of the focus light is detected by the CCD image sensor 35 through the same path as the cornea reflection light of the alignment light. A light reception image (split index) by the CCD image sensor 35 is displayed on the display device 3 together with the observation image. The arithmetic control unit 200 analyzes the position of the split index and moves the photographing focusing lens 31 and the focus optical system 60 to perform focusing as in the conventional case (autofocus function). Alternatively, focusing may be performed manually while visually checking the split indicator.

  The dichroic mirror 46 branches the optical path for OCT measurement from the optical path for fundus photography. The dichroic mirror 46 reflects light in a wavelength band used for OCT measurement and transmits light for fundus photographing. In this OCT measurement optical path, a collimator lens unit 40, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, and a relay lens 45 are sequentially arranged from the OCT unit 100 side. Is provided.

  The optical path length changing unit 41 is movable in the direction of the arrow shown in FIG. 1, and changes the optical path length of the optical path for OCT measurement (the optical path of measurement light). This change in the optical path length is used for correcting the optical path length according to the axial length of the eye E, adjusting the interference state, moving the region depicted in the OCT image, and the like. The optical path length changing unit 41 includes, for example, a corner cube and a moving mechanism (a moving mechanism 41A described later) that moves the corner cube.

  The optical scanner 42 changes the traveling direction of light (measurement light LS) passing through the optical path for OCT measurement. Thereby, the fundus oculi Ef or the anterior segment can be scanned with the measurement light LS. The optical scanner 42 includes, for example, a galvanometer mirror that scans the measurement light LS in the x direction, a galvanometer mirror that scans in the y direction, and a mechanism that drives these independently. Thereby, the measurement light LS can be scanned in an arbitrary direction on the xy plane.

[OCT unit]
An example of the configuration of the OCT unit 100 will be described with reference to FIG. The OCT unit 100 is provided with an optical system for acquiring an OCT image of an area including at least a part of the front surface of the subject's face. The area may be a peripheral area of the eye E including the eye E (for example, the cornea). The peripheral area may be an area including the subject's eyelid, nose, or cheek. This optical system has the same configuration as a conventional swept source type OCT apparatus. That is, this optical system divides the light from the wavelength sweep type (wavelength scanning type) light source into the measurement light and the reference light, and returns the return light of the measurement light from the eye E and the reference light via the reference light path. An interference optical system that generates interference light by causing interference and detects the interference light. The detection result (detection signal) of the interference light by the interference optical system is an interference signal indicating the spectrum of the interference light, and is sent to the arithmetic control unit 200.

  In the case of a spectral domain type OCT apparatus, a light source that outputs a low-coherence light source is provided instead of a wavelength swept light source, and an optical member that spectrally decomposes interference light is provided. In general, for the configuration of the OCT unit 100, a known technique corresponding to the type of OCT can be arbitrarily applied.

  The light source unit 101 is configured to include a wavelength sweep type (wavelength scanning type) light source capable of sweeping (scanning) the wavelength of emitted light, as in a general swept source type OCT apparatus. The swept wavelength light source includes a laser light source including a resonator. The light source unit 101 temporally changes the output wavelength in the near-infrared wavelength band that cannot be visually recognized by the human eye.

  The light L0 output from the light source unit 101 is guided to the polarization controller 103 by the optical fiber 102 and its polarization state is adjusted. The polarization controller 103 adjusts the polarization state of the light L0 guided through the optical fiber 102, for example, by applying stress from the outside to the looped optical fiber 102.

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

  The reference light LR is guided to the collimator 111 by the optical fiber 110 and becomes a parallel light beam. The reference light LR that has become a parallel light beam is guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 functions as a delay unit for matching the optical path length (optical distance) of the reference light LR and the optical path length of the measurement light LS. The dispersion compensation member 113 functions as a dispersion compensation means for matching the dispersion characteristics between the reference light LR and the measurement light LS.

  The corner cube 114 folds the traveling direction of the reference light LR that has become a parallel light beam by the collimator 111 in the reverse direction. The optical path of the reference light LR incident on the corner cube 114 and the optical path of the reference light LR emitted from the corner cube 114 are parallel. The corner cube 114 is movable in a direction along the incident optical path and the outgoing optical path of the reference light LR. By this movement, the length of the optical path of the reference light LR is changed.

  2 and 3, the optical path length changing unit 41 for changing the length of the optical path of the measurement light LS (measurement optical path, measurement arm) and the optical path of the reference light LR (reference optical path, reference) Both corner cubes 114 for changing the length of the arm) are provided. However, only the corner cube 114 may be provided. It is also possible to change the optical path length difference between the measurement optical path and the reference optical path using optical members other than these.

  The reference light LR that has passed through the corner cube 114 passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel light beam into a focused light beam by the collimator 116, and enters the optical fiber 117. The reference light LR incident on the optical fiber 117 is guided to the polarization controller 118 and the polarization state of the reference light LR is adjusted.

  For example, the polarization controller 118 has the same configuration as the polarization controller 103. The reference light LR whose polarization state is adjusted by the polarization controller 118 is guided to the attenuator 120 by the optical fiber 119, and the light quantity is adjusted under the control of the arithmetic control unit 200. The reference light LR whose light amount has been adjusted by the attenuator 120 is guided to the fiber coupler 122 by the optical fiber 121.

  On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and converted into a parallel light beam by the collimator lens unit 40. The measurement light LS converted into a parallel light beam is guided to the dichroic mirror 46 via the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, the mirror 44, and the relay lens 45. The measurement light LS guided to the dichroic mirror 46 is reflected by the dichroic mirror 46, refracted by the objective lens 22, and irradiated to the eye E. The measurement light LS is scattered (including reflection) at various depth positions of the eye E. The return light of the measurement light LS including such backscattered light travels in the reverse direction on the same path as the forward path, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

  The fiber coupler 122 combines (interferes) the measurement light LS incident through the optical fiber 128 and the reference light LR incident through the optical fiber 121 to generate interference light. The fiber coupler 122 branches the interference light between the measurement light LS and the reference light LR at a predetermined branching ratio (for example, 1: 1), thereby generating a pair of interference lights LC. The pair of interference lights LC emitted from the fiber coupler 122 are guided to the detector 125 by optical fibers 123 and 124, respectively.

  The detector 125 is, for example, a balanced photodiode that includes a pair of photodetectors that respectively detect a pair of interference lights LC and outputs a difference between detection results obtained by the pair of photodetectors. The detector 125 sends the detection result (interference signal) to a DAQ (Data Acquisition System) 130. The clock 130 is supplied from the light source unit 101 to the DAQ 130. The clock KC is generated in synchronization with the output timing of each wavelength swept (scanned) by the wavelength sweep type light source within the set wavelength range (wavelength sweep width) in the light source unit 101. For example, the light source unit 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then generates a clock KC based on the result of detecting these combined lights. Generate. The DAQ 130 samples the detection result of the detector 125 based on the clock KC. The DAQ 130 sends the sampled detection result of the detector 125 to the arithmetic control unit 200. Further, in order to cope with a case where the measurement range (imaging range) is changed, the sampling timing may be changeable. Note that the DAQ 130 may acquire the detection result of the detector 125 without using the clock KC. The arithmetic control unit 200 performs a Fourier transform or the like on the spectrum distribution based on the detection result obtained by the detector 125 for each series of wavelength scans (for each A line), for example, thereby obtaining a reflection intensity profile in each A line. Form. Furthermore, the arithmetic control unit 200 can form image data by imaging the reflection intensity profile of each A line.

  Prior to imaging and measurement of the eye E, the ophthalmologic apparatus 1 performs alignment (XY alignment) in a direction orthogonal to the optical axis of the apparatus optical system (interference optical system) by a known method, It is possible to perform alignment (Z alignment) in the direction.

  When performing the Z alignment, the ophthalmologic apparatus 1 scans a region including at least a part of the front surface of the subject's face by the OCT unit 100 to acquire OCT information, and analyzes the acquired OCT information. A position corresponding to at least a part of the region is specified. When the eye E is included in the region, the ophthalmologic apparatus 1 relatively moves the eye E and the apparatus optical system based on the specified position. When the eye E is not included in the area, the ophthalmologic apparatus 1 can relatively move the area of the subject's face and the apparatus optical system based on the specified position.

  Hereinafter, the ophthalmologic apparatus 1 performs alignment in the optical axis direction of the apparatus optical system by relatively moving the cornea of the eye E to be examined and the apparatus optical system. That is, the ophthalmologic apparatus 1 acquires the OCT information by scanning the peripheral region of the eye E including the cornea of the eye E, and analyzes the acquired OCT information to thereby determine the position (depth) of the region corresponding to the cornea. Direction position, z-direction position). The ophthalmologic apparatus 1 relatively moves the cornea of the eye E to be examined and the apparatus optical system using the specified position.

  FIG. 4 is an explanatory diagram of Z alignment in the ophthalmologic apparatus 1 according to the embodiment. 4, parts that are the same as those in FIGS. 2 and 3 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

  For the Z alignment, for example, the relative position between the surface of the objective lens 22 on the eye E side and the cornea (for example, the apex of the cornea) of the eye E is used. Specifically, the ophthalmologic apparatus 1 identifies the distance in the z direction between the surface of the objective lens 22 and the cornea from this relative position, and covers the z direction so that the identified distance becomes a predetermined working distance. Z alignment is performed by relatively moving the optometry E and the optical system.

  In this embodiment, as shown in FIG. 4, a predetermined intermediate point Zr is provided between the surface of the objective lens 22 on the eye E side and the cornea of the eye E. Thereby, the relative position is specified by the first relative position between the surface on the eye E side of the objective lens 22 and the intermediate point Zr, and the second relative position between the intermediate point Zr and the cornea of the eye E. Is possible. The intermediate point Zr is provided so that the second relative position can be specified by the OCT information. Specifically, as the intermediate point Zr, a position where the optical path length of the reference light LR and the optical path length of the measurement light LS coincide with each other in the interference optical system is used. Hereinafter, a position where the optical path length of the reference light LR and the optical path length of the measurement light LS coincide with each other in such an interference optical system is referred to as a zero position (OCT zero position).

  In this case, the distance LL obtained from the first relative position can be specified by the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS in the interference optical system. The optical path length difference can be specified from the state (monitor value, etc.) of the optical path length changing unit or the control content for these. The state of the optical path length changing unit includes the position of the corner cube constituting the optical path length changing unit 41 that changes the optical path length of the measurement light LS, or the corner cube included in the optical path length changing unit that changes the optical path length of the reference light LR. There are 114 positions.

  Further, the distance Lzd obtained from the second relative position can be specified from the position corresponding to the cornea with respect to the zero position by analyzing the OCT information. For example, the position zd in the depth direction of the region corresponding to the cornea with respect to the zero position as the intermediate point Zr is specified from the OCT image IMG as the OCT information. Therefore, the distance Lzd between the zero position and the cornea is uniquely obtained from the position zd. The ophthalmologic apparatus 1 can perform Z alignment by relatively moving the eye E and the apparatus optical system in the z direction so that the distance (LL + Lzd) becomes the working distance of the objective lens 22.

  The ophthalmologic apparatus 1 specifies the position of the surface of the objective lens 22 and the position of the corneal apex of the eye E using an imaging unit (or detection unit) provided separately, and the distance LL from the two specified positions. May be requested.

[Calculation control unit]
The configuration of the arithmetic control unit 200 will be described. The arithmetic control unit 200 analyzes the interference signal input from the detector 125 to form an OCT image of the eye E or calculates the intraocular distance of the eye E. The arithmetic processing for forming the OCT image and the processing for calculating the intraocular distance are the same as those of the conventional swept source type ophthalmologic apparatus.

  The arithmetic control unit 200 controls each part of the fundus camera unit 2, the display device 3, and the OCT unit 100. For example, the arithmetic control unit 200 displays the OCT image of the eye E to be examined, the calculation result of the intraocular distance, and the like on the display device 3.

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

[Control system]
The configuration of the control system (processing system) of the ophthalmologic apparatus 1 will be described with reference to FIG. In FIG. 5, some components of the ophthalmologic apparatus 1 are omitted, and components particularly necessary for explaining this embodiment are selectively shown.

(Control part)
The arithmetic control unit 200 includes a control unit 210, an image forming unit 220, and a data processing unit 230. The control unit 210 includes, for example, a microprocessor, a RAM, a ROM, a hard disk drive, a communication interface, and the like. The control unit 210 is provided with a main control unit 211 and a storage unit 212.

(Main control unit)
The main control unit 211 performs the various controls described above. In particular, as shown in FIG. 5, the main control unit 211 controls the movement mechanisms 31A, 41A and 43A, the CCD image sensors 35 and 38, the LCD 39, and the optical scanner 42 of the fundus camera unit 2. The main control unit 211 controls the light source unit 101, the moving mechanism 114A, the detector 125, the DAQ 130, and the like of the OCT unit 100.

  The moving mechanism 31 </ b> A moves the photographing focusing lens 31 along the optical axis of the photographing optical system 30. The moving mechanism 31A is provided with a holding member that holds the photographing focusing lens 31, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. The actuator is constituted by, for example, a pulse motor. The transmission mechanism is configured by, for example, a combination of gears, a rack and pinion, or the like. Thereby, the moving mechanism 31 </ b> A under the control of the control unit 210 moves the photographing focusing lens 31, thereby changing the focusing position of the photographing optical system 30. Note that the moving mechanism 31 </ b> A may move the photographing focusing lens 31 along the optical axis of the photographing optical system 30 by manual or user operation on the operation unit 242.

  The moving mechanism 41A moves the corner cube constituting the optical path length changing unit 41 along the optical path of the measuring light LS. The moving mechanism 41A includes a holding member that holds the corner cube, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. The actuator is constituted by, for example, a pulse motor. The transmission mechanism is configured by, for example, a combination of gears, a rack and pinion, or the like. As a result, the moving mechanism 41A controlled by the control unit 210 moves the corner cube, thereby changing the optical path length of the measuring light LS. Note that the moving mechanism 41 </ b> A may move the corner cube along the optical path of the measurement light LS by manual or user operation on the operation unit 242.

  The moving mechanism 43A moves the OCT focusing lens 43 along the optical path of the measurement light LS. The moving mechanism 43A is provided with a holding member that holds the OCT focusing lens 43, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. The actuator is constituted by, for example, a pulse motor. The transmission mechanism is configured by, for example, a combination of gears, a rack and pinion, or the like. As a result, the moving mechanism 43A under the control of the control unit 210 moves the OCT focusing lens 43, thereby changing the focusing position of the measurement light LS. Note that the moving mechanism 43A may move the OCT focusing lens 43 along the optical path of the measurement light LS by manual or user operation on the operation unit 242.

  The optical system driving unit 1A drives a moving mechanism that three-dimensionally moves the apparatus optical system shown in FIGS. The moving mechanism is provided with a holding member that holds the apparatus optical system, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. The actuator is constituted by, for example, a pulse motor. The transmission mechanism is configured by, for example, a combination of gears, a rack and pinion, or the like. The main control unit 211 can control the optical system driving unit 1A to move the optical system provided in the ophthalmologic apparatus 1 three-dimensionally. This control is used in alignment and tracking. Tracking refers to moving the apparatus optical system in accordance with the movement of the eye E. When tracking is performed, alignment and focusing are performed in advance. Tracking maintains a suitable positional relationship in which alignment and focus are achieved by moving the apparatus optical system in real time according to the position and orientation of the eye E based on an image obtained by taking a moving image of the eye E. It is a function.

  The moving mechanism 114A moves the corner cube 114 provided in the reference optical path. The moving mechanism 114A includes a holding member that holds the corner cube 114, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. Thereby, the optical path length of the reference light LR is changed. Note that the moving mechanism 114A may move the corner cube 114 along the reference optical path manually or by a user operation on the operation unit 242.

(Memory part)
The storage unit 212 stores various data. Examples of data stored in the storage unit 212 include image data of an OCT image, image data of a fundus image, intraocular distance data of an eye to be examined, and eye information to be examined. The eye information includes information about the subject such as patient ID and name, and information about the eye such as left / right eye identification information. The storage unit 212 stores various programs and data for operating the ophthalmologic apparatus 1.

  In this embodiment, the storage unit 212 stores correspondence information 212a for specifying the distance LL in FIG. 4 in advance. The correspondence information 212a is information in which information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS and the distance between the position of the objective lens 22 and the zero position are associated in advance. Here, the information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measuring light LS includes the position of the corner cube constituting the optical path length changing unit 41, the position of the corner cube 114, and the like. For example, the main control unit 211 specifies the position of the corner cube constituting the optical path length changing unit 41 and the position of the corner cube 114 from the control content for the moving mechanism 41A or the moving mechanism 114A. You may acquire the position of the corner cube which comprises the optical path length change part 41, and the position of the corner cube 114 from the detection means which detects these. Further, the main control unit 211 may specify the position of the corner cube constituting the optical path length changing unit 41 or the position of the corner cube 114 from the information acquired by accessing the moving mechanism 41A or the moving mechanism 114A. Good. The correspondence information 212a may be stored in the data processing unit 230.

(Image forming part)
The image forming unit 220 forms image data of a tomographic image of the eye E based on the interference signal from the detector 125 (DAQ 130). That is, the image forming unit 220 forms image data of the eye E based on the detection result of the interference light LC by the interference optical system. This processing includes processing such as noise removal (noise reduction), filter processing, and FFT (Fast Fourier Transform). The image data acquired in this way is a data set including a group of image data formed by imaging the reflection intensity profiles in a plurality of A lines.

  In order to improve the image quality, it is possible to superimpose (addition average) a plurality of data sets acquired by repeating scanning with the same pattern a plurality of times.

  Further, the image forming unit 220 generates two or more split target images from the image signal detected by the CCD 35 based on the return lights of the two or more split targets from the eye E to be examined that have passed through the photographing focusing lens 31. It is possible to form a rendered image. The formation of the image in which the two or more split target images are drawn may be performed by the main control unit 211.

  The image forming unit 220 includes, for example, the circuit board described above. In this specification, “image data” and “image” based thereon may be identified. Moreover, the part of the eye E to be examined and the image thereof may be identified.

(Data processing part)
The data processing unit 230 performs various types of data processing (image processing) and analysis processing on the image formed by the image forming unit 220. For example, the data processing unit 230 executes correction processing such as image luminance correction and dispersion correction. Further, the data processing unit 230 performs various types of image processing and analysis processing on images (fundus image, anterior eye image, etc.) obtained by the fundus camera unit 2.

  The data processing unit 230 can form volume data (voxel data) of the eye E by performing known image processing such as interpolation processing for interpolating pixels between tomographic images. When displaying an image based on volume data, the data processing unit 230 performs a rendering process on the volume data to form a pseudo three-dimensional image when viewed from a specific viewing direction.

  The data processing unit 230 includes an analysis unit 231 and a distance specifying unit 232. Based on the interference signal obtained by the detector 125, the analysis unit 231 specifies a position corresponding to a region including at least a part of the front surface of the subject's face (for example, the pupil and the cornea). The analysis unit 231 can also specify the position from the OCT image formed by the image forming unit 220 based on the interference signal. For example, the analysis unit 231 identifies a position corresponding to the zero position and a position corresponding to the cornea by analyzing the OCT image in the optical axis direction of the apparatus optical system. Note that the analysis unit 231 may specify the position directly from the interference signal.

  The distance specifying unit 232 specifies the distance LL in the z direction between the position of the objective lens 22 and the zero position based on the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS. Specifically, the distance specifying unit 232 receives information corresponding to the optical path length difference acquired by the main control unit 211, and specifies the distance LL by referring to the correspondence information 212a based on the information. For example, the distance specifying unit 232 specifies the distance associated with the information corresponding to the optical path length difference as the distance LL in the correspondence information 212a. The distance specifying unit 232 may specify the distance associated with the information corresponding to the optical path length difference closest to the optical path length difference as the distance LL in the correspondence information 212a. Alternatively, the distance specifying unit 232 may specify the distance LL by interpolating two or more distances associated with information corresponding to two or more optical path length differences close to the above optical path length difference in the correspondence information 212a. .

  The data processing unit 230 may calculate one or more intraocular distances of the eye E based on detection data of two or more interference lights LC by the interference optical system. The data processing unit 230 calculates the intraocular distance of the eye E based on the interval between the positions of the two interference signals based on the two interference lights included in the detection data. Such a data processing unit 230 can calculate corneal thickness, anterior chamber depth, lens thickness, axial length, and the like.

  The data processing unit 230 can perform alignment between the fundus image and the OCT image. When the fundus image and the OCT image are acquired in parallel, since both optical systems are coaxial, the optical axis of the imaging optical system 30 is used to (substantially) simultaneously acquire the fundus image and the OCT image. Can be aligned with reference to. Regardless of the acquisition timing of the fundus image and the OCT image, the front image obtained by projecting at least a part of the image area corresponding to the fundus oculi Ef of the OCT image onto the xy plane is aligned with the fundus image. By doing so, it is possible to align the OCT image and the fundus image. This alignment method is applicable even when the fundus image acquisition optical system and the OCT optical system are not coaxial. Even if both optical systems are not coaxial, if the relative positional relationship between both optical systems is known, the same alignment as in the coaxial case is executed with reference to this relative positional relationship. It is possible.

  The data processing unit 230 that functions as described above includes, for example, a microprocessor, a RAM, a ROM, a hard disk drive, a circuit board, and the like. In a storage device such as a hard disk drive, a computer program for causing the microprocessor to execute the above functions is stored in advance.

(User interface)
The user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes the display device of the arithmetic control unit 200 and the display device 3 described above. The operation unit 242 includes the operation device of the arithmetic control unit 200 described above. The operation unit 242 may include various buttons and keys provided on the housing of the ophthalmologic apparatus 1 or outside. Further, the display unit 241 may include various display devices such as a touch panel provided in the housing of the fundus camera unit 2.

  The display unit 241 and the operation unit 242 do not need to be configured as individual devices. For example, a device in which a display function and an operation function are integrated, such as a touch panel, can be used. In that case, the operation unit 242 includes the touch panel and a computer program. The operation content for the operation unit 242 is input to the control unit 210 as an electrical signal. Further, operations and information input may be performed using the graphical user interface (GUI) displayed on the display unit 241 and the operation unit 242.

  Of the optical systems shown in FIGS. 2 and 3, at least the optical system included in the OCT unit 100 is an example of the “optical system” according to the embodiment. The optical system drive unit 1A is an example of the “drive unit” according to the embodiment. The position corresponding to the cornea is an example of the “first position” according to the embodiment. The optical system included in the OCT unit 100 divides the light from the light source into measurement light and reference light, and causes interference light to interfere with the return light of the measurement light from the eye to be examined and the reference light passing through the reference light path. It is an example of an “interference optical system” that generates and detects the interference light. The zero position (OCT zero position) where the optical path length of the reference light LR and the optical path length of the measurement light LS coincide is an example of the “second position” according to the embodiment. The OCT unit 100, the image forming unit 220, or the imaging optical system 30 is an example of the “imaging unit” according to the embodiment. The distance between the surface of the objective lens 22 on the eye E side and the intermediate point Zr is an example of the “first distance” according to the embodiment. The distance between the intermediate point Zr and the cornea of the eye E is an example of the “second distance” according to the embodiment.

[Operation example]
The operation of the ophthalmologic apparatus 1 will be described. Examples of the operation of the ophthalmologic apparatus 1 are shown in FIGS. First, correspondence information is registered before alignment according to the embodiment, and the above-described alignment is performed using the registered correspondence information.

  FIG. 6 shows a flowchart of an operation example of the ophthalmologic apparatus 1 according to the embodiment. FIG. 6 illustrates an operation example of the correspondence information registration process. This registration process may be performed at the time of shipment of the ophthalmologic apparatus 1 or every predetermined time after shipment.

(S1)
First, a measurement sample (optical member) is arranged at a position separated from the objective lens 22 by a known predetermined distance DT. An example of the measurement sample is a reflection mirror. The main control unit 211 controls the OCT unit 100 and the like to execute an OCT scan on the measurement sample and acquire OCT information. Specifically, the main control unit 211 turns on the light source unit 101 and controls the optical scanner 42 to start scanning the eye E with the measurement light LS based on the light L0 from the light source unit 101. For example, the image forming unit 220 forms an OCT image as the OCT information based on the detection result of the interference light by the detector 125 as described above.

(S2)
The main control unit 211 causes the analysis unit 231 to analyze whether or not the measurement sample is included in a predetermined measurement range (imaging range) from the OCT information acquired in S1. For example, the analysis unit 231 determines whether or not the position of the intensity of the return light of the measurement light LS reflected from the measurement sample is included in a predetermined range, so that the measurement sample is included in the measurement range. It can be determined whether or not. When it is determined that the measurement sample is included in the predetermined measurement range (S2: Y), the operation of the ophthalmologic apparatus 1 proceeds to S4. When it is determined that the measurement sample is not included in the predetermined measurement range (S2: N), the operation of the ophthalmologic apparatus 1 proceeds to S3.

(S3)
When it is determined from the OCT information acquired in S1 that the measurement sample is not included in the predetermined measurement range (S2: N), the main control unit 211 controls the moving mechanism 41A or the moving mechanism 114A. Thus, the optical path length of the reference light LR or the optical path length of the measurement light LS is changed. Thereby, the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS is changed, and the position of the return light of the measurement light LS reflected from the measurement sample in the OCT information changes in the z direction. For example, when the OCT information is an OCT image, the position of the region corresponding to the measurement sample depicted in the OCT image changes in the z direction. Thereafter, the operation of the ophthalmologic apparatus 1 proceeds to S1.

(S4)
When it is determined from the OCT information acquired in S1 that the measurement sample is included in the predetermined measurement range (S2: Y), the main control unit 211 performs the processing based on the OCT information acquired in S1. The analysis unit 231 specifies the position of the region corresponding to the cornea of the optometry E. The analysis unit 231 specifies the position of the region in the depth direction, and obtains the depth (z-direction distance) of the position with reference to the zero position.

(S5)
Subsequently, the main control unit 211 subtracts the distance corresponding to the depth specified in S4 from the distance DT of S1 to obtain the distance between the objective lens and the zero position.

(S6)
The main control unit 211 determines the position of the current corner cube (the corner cube constituting the optical path length changing unit 41 or the corner cube 114) as information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS. Refer to As described above, the main control unit 211 can specify the position of the corner cube constituting the optical path length changing unit 41 and the position of the corner cube 114 from the control contents for the moving mechanism 41A or the moving mechanism 114A.

(S7)
The main control unit 211 generates correspondence information by associating the distance between the objective lens and the zero position obtained in S5 and the position of the corner cube specified in S6, and stores the correspondence information in the storage unit 212 as correspondence information 212a.

(S8)
The main control unit 211 determines whether there is a next optical path length. When it is determined that there is the next optical path length (S8: Y), the operation of the ophthalmologic apparatus 1 proceeds to S9. When it is determined that there is no next optical path length (S8: N), the operation of the ophthalmologic apparatus 1 ends (end).

(S9)
When it is determined that there is a next optical path length (S8: Y), the main control unit 211 controls the moving mechanism 41A or the moving mechanism 114A, so that the reference light LR becomes a predetermined optical path length difference. Or the optical path length of the measurement light LS is changed. Thereafter, the operation of the ophthalmologic apparatus 1 proceeds to S1.

As described above, the correspondence information 212a associating the plurality of optical path length differences MT ₁ , MT ₂ , MT ₃ ,... And the objective lens / zero position distances LL ₁ , LL ₂ , LL ₃ ,. It is registered in the storage unit 212 (see FIG. 7).

  Note that correspondence information may be registered for each of a plurality of known predetermined distances (see S1). In this case, when performing alignment described later, one piece of correspondence information is selected from a plurality of pieces of correspondence information, and the distance between the objective lens and the zero position can be specified using the selected correspondence information. One objective lens / zero position replacement distance may be specified from a plurality of pieces of correspondence information. Thereby, the distance between the objective lens and the zero position can be specified with high accuracy from the optical path length difference.

  When the correspondence information 212a as illustrated in FIG. 7 is stored in the storage unit 212, the ophthalmologic apparatus 1 can execute alignment at an arbitrary timing.

  FIG. 8 and FIG. 9 are flowcharts showing an example of alignment operation in the ophthalmic apparatus 1 according to the embodiment.

(S20)
The main control unit 211 moves the optical system to the initial position by controlling the optical system driving unit 1A. The initial position may be a position where the distance between the eye E and the objective lens 22 is sufficiently larger than the working distance of the objective lens 22. Thereby, it is easy to specify the alignment target position (corneal position) from a wide area including the eye E.

(S21)
Next, the main control unit 211 causes the imaging optical system 30 to image the peripheral part of the eye E to acquire a planar image of the eye E. The planar image acquired in S21 may be an xy planar image generated from the OCT information acquired using the OCT unit 100, a projection image, or the like.

(S22)
The main control unit 211 causes the analysis unit 231 to identify a characteristic part from the planar image acquired in S21. The characteristic part includes the cornea (pupil) and the like. For example, the analysis unit 231 specifies a corneal region by a known method.

(S23)
The main control unit 211 controls the optical system drive unit 1A so that the center of the cornea from the specified cornea region is optically aligned in the xy direction so as to be the center of the planar image (position of the optical axis) acquired in S21. The system is moved (XY alignment).

(S24)
Subsequently, the main control unit 211 turns on the light source unit 101 and controls the optical scanner 42 to start scanning the eye E with the measurement light LS based on the light L0 from the light source unit 101. For example, the image forming unit 220 forms an OCT image based on the detection result of the interference light by the detector 125 as described above.

(S25)
The main control unit 211 causes the analysis unit 231 to analyze whether or not a region corresponding to the cornea of the eye E to be examined is included in a predetermined measurement range (imaging range) from the OCT information acquired in S24. For example, the analysis unit 231 measures the region corresponding to the cornea by determining whether or not the position of the intensity of the return light of the measurement light LS reflected from the cornea of the eye E is within a predetermined range. Whether it is included in the range can be determined. When it is determined that the region corresponding to the cornea of the eye E to be examined is included in the predetermined measurement range (S25: Y), the operation of the ophthalmologic apparatus 1 proceeds to S27. When it is determined that the region corresponding to the cornea of the eye E is not included in the predetermined measurement range (S25: N), the operation of the ophthalmologic apparatus 1 proceeds to S26.

(S26)
When it is determined from the OCT information acquired in S24 that the region corresponding to the cornea of the eye E is not included in the predetermined measurement range (S25: N), the main control unit 211 moves the moving mechanism 41A or the moving The optical path length of the reference light LR or the optical path length of the measurement light LS is changed by controlling the mechanism 114A. Thereby, the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS is changed, and the position of the return light of the measurement light LS reflected from the cornea of the eye E in the OCT information changes in the z direction. For example, when the OCT information is an OCT image, the position of the region corresponding to the cornea of the eye E to be examined depicted in the OCT image changes in the z direction. Thereafter, the operation of the ophthalmologic apparatus 1 proceeds to S24.

(S27)
When it is determined from the OCT information acquired in S24 that the region corresponding to the cornea of the eye E to be examined is included in the predetermined measurement range (S25: Y), the main control unit 211 is acquired in S24. Based on the OCT information, the analysis unit 231 specifies the position of the region corresponding to the cornea of the eye E to be examined. The analysis unit 231 specifies the position of the region in the depth direction, and obtains the depth (z-direction distance) of the position with reference to the zero position.

(S28)
Subsequently, the main control unit 211 detects the current corner cube (the corner cube constituting the optical path length changing unit 41 or the corner cube 114) as information corresponding to the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS. ), The correspondence information 212a is referred to.

(S29)
The main control unit 211 identifies the distance between the objective lens and the zero position from the correspondence information 212a. The main control unit 211 adds the identified distance between the objective lens and the zero position and the distance corresponding to the depth identified in S27, and thereby the surface of the objective lens 22 on the eye E side and the eye E to be examined. The distance between the objective lens and the cornea is calculated as the distance between the corneas. The distance between the objective lens and the cornea may be obtained by the distance specifying unit 232.

(S30)
The main control unit 211 compares the objective lens / corneal distance calculated in S <b> 29 with the working distance of the objective lens 22.

(S31)
The main control unit 211 obtains a difference between the objective lens-corneal distance and the working distance of the objective lens 22 and determines whether the difference is equal to or less than a predetermined target value. This target value corresponds to the allowable value of the Z alignment shift amount. When it is determined that the difference is equal to or less than the target value (S31: Y), the operation of the ophthalmologic apparatus 1 ends (end).

  When it is determined that the difference is equal to or less than the target value (S31: Y), the main control unit 211 determines that the adjustment of the relative positional relationship between the eye E and the apparatus optical system is completed, and the measurement light You may make it perform adjustment of OCT imaging systems, such as LS focus position and a polarization state. When adjusting the OCT imaging system, the main control unit 211 performs an OCT scan on the eye E to form an OCT image, and changes the optical path length changing unit so that the contrast of the image of the region of interest is maximized. 41 and each part of the OCT unit 100 can be controlled. For example, the main control unit 211 adjusts the optical path length difference by moving the position of the corner cube (the corner cube or the corner cube 114 that constitutes the optical path length changing unit 41), or the imaging focusing lens 31 by the moving mechanism 31A. Or the polarization state is changed by controlling the polarization controllers 103 and 118.

  When it is determined in S31 that the difference is not less than or equal to the target value (S31: N), the operation of the ophthalmologic apparatus 1 proceeds to S32.

(S32)
When it is determined in S31 that the difference is not less than or equal to the target value (S31: N), the main control unit 211 moves the apparatus optical system in the z direction by controlling the optical system driving unit 1A. Thereafter, the operation of the ophthalmologic apparatus 1 proceeds to S24.

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

  The ophthalmologic apparatus (1) according to the embodiment includes an optical system (an optical system included in the OCT unit 100 and an optical system through which measurement light passes), a drive unit (optical system drive unit 1A), an analysis unit (232), And a control unit (210, main control unit 211). The optical system is used to collect data by scanning an area including at least a portion of the front surface of the subject's face using optical coherence tomography. The drive unit relatively moves the eye to be examined (E) and the optical system in the optical axis direction (z direction) of the optical system. The analysis unit specifies a first position (a position corresponding to the cornea) corresponding to at least a part of the region based on the data collected by the optical system. The control unit moves the eye to be examined and the optical system relative to each other by controlling the drive unit based on the first position specified by the analysis unit.

  According to such a configuration, a position corresponding to at least a part of the area is specified based on data collected by scanning an area including at least a part of the front surface of the subject's face using OCT. Since the drive unit is controlled based on the specified position to move the eye to be examined and the optical system relative to each other, alignment of the optical axis direction of the optical system is performed using information obtained by OCT. It becomes possible to do. Thereby, it is not necessary to provide an optical system dedicated for alignment, and the ophthalmologic apparatus can be miniaturized. In addition, since the positional relationship between the front surface of the subject's face and the apparatus can be grasped, it is possible to adjust the positions of the subject and the optical system while ensuring safety.

  In the ophthalmologic apparatus according to the embodiment, the optical system may include an objective lens (22) and an interference optical system. The interference optical system divides light (L0) from the light source (light source unit 101) into reference light (LR) and measurement light (LS), irradiates the eye to be examined with the measurement light via the objective lens, and the eye to be examined. The interference light (LC) between the return light of the measurement light from the light and the reference light is detected. The analysis unit identifies the first position based on the detection result of the interference light detected by the interference optical system, and the control unit determines the position of the objective lens, the first position, the optical path length of the reference light, and the measurement light. The eye to be examined and the optical system may be relatively moved based on the second position (zero position, direct current component position) that matches the optical path length.

  According to such a configuration, the position of the objective lens, the first position based on the detection result of the interference light in the interference optical system, and the second position where the optical path length of the reference light and the optical path length of the measurement light coincide with each other. Since the alignment is performed using the optical system, alignment in the direction of the optical axis of the optical system can be performed without providing an optical system dedicated to alignment.

  In the ophthalmologic apparatus according to the embodiment, the control unit includes a first distance between the position of the objective lens and the second position, and a position corresponding to the second position in the detection result of the interference light and the first position. The eye to be examined and the optical system may be moved relative to each other based on the second distance therebetween.

  According to such a configuration, since the alignment is performed using the first distance and the second distance that can be specified from the information obtained by OCT, the optical system can be provided without providing an optical system dedicated to alignment. It is possible to perform alignment in the direction of the optical axis.

  In the ophthalmologic apparatus according to the embodiment, the control unit relatively moves the eye to be examined and the optical system so that the sum of the first distance and the second distance becomes a predetermined working distance (the working distance of the objective lens 22). You may let them.

  According to such a configuration, it is possible to execute alignment in the direction of the optical axis of the optical system without providing an optical system dedicated to alignment.

  In the ophthalmic apparatus according to the embodiment, the interference optical system includes an optical path length changing unit (41 or an optical path length changing unit including the corner cube 114) that relatively changes the optical path length of the reference light and the optical path length of the measurement light. ) And a distance specifying unit (232) that specifies the first distance based on the optical path length difference between the optical path of the reference light and the optical path of the measurement light, which is changed by the optical path length changing unit.

  According to such a configuration, since the first distance is specified based on the optical path length difference between the optical path of the reference light and the optical path of the measurement light, OCT is used without providing an optical system dedicated for alignment. It becomes possible to execute alignment in the optical axis direction of the optical system only with the acquired information.

  In the ophthalmologic apparatus according to the embodiment, the optical path length changing unit may include a corner cube that is arranged in the optical path of the reference light or the optical path of the measurement light and is movable along the optical path.

  According to such a configuration, it is possible to simplify the configuration and control of an ophthalmologic apparatus capable of alignment in the direction of the optical axis of the optical system using information obtained by OCT.

  The ophthalmologic apparatus according to the embodiment includes a storage unit (212) that stores in advance correspondence information (212a) that associates information corresponding to the optical path length difference with the first distance, and the distance specifying unit is stored in the storage unit. The first distance may be specified based on the stored correspondence information.

  According to such a configuration, it is possible to provide an ophthalmologic apparatus capable of highly accurate alignment in the direction of the optical axis of the optical system without providing an optical system dedicated for alignment.

  The ophthalmologic apparatus according to the embodiment includes an imaging unit (imaging optical system 30) that images at least a part of the above-described region, and the drive unit is in a direction (xy direction) intersecting the optical axis direction of the optical system. The control unit moves the eye to be examined and the optical system in a direction intersecting the optical axis direction of the optical system based on the photographed image obtained by the photographing unit. After that, the eye to be examined and the optical system may be relatively moved in the optical axis direction based on the first position.

  According to such a configuration, it is possible to provide an ophthalmologic apparatus capable of alignment in the direction of the optical axis of an optical system using information obtained by OCT and capable of alignment in a direction crossing the optical axis. Will be able to.

  Moreover, the ophthalmologic apparatus which concerns on embodiment contains the support part (440) which supports a face, and a drive part may move a support part and an optical system relatively.

  According to such a configuration, an ophthalmologic apparatus capable of performing high-precision alignment of the face of the subject supported by the support unit and the optical system in the direction using information obtained by OCT. Will be able to provide.

  In the ophthalmologic apparatus according to the embodiment, the optical system may scan a region including the cornea, the eyelid, the nose, or the cheek.

  According to such a configuration, it is possible to perform alignment between an optical system and a region including a subject's cornea, heel, nose, or cheek using information obtained by OCT.

<Modification>
The configuration described above is merely an example for favorably implementing the present invention. Therefore, arbitrary modifications (omitted, replacement, addition, etc.) within the scope of the present invention can be made as appropriate.

  In the above embodiment, the optical path length difference between the optical path of the reference light LR and the optical path of the measurement light LS is changed by changing the position of the corner cube. It is not limited. For example, the optical path length difference may be changed by moving the fundus camera unit 2 or the OCT unit 100 with respect to the eye E to change the optical path length of the measurement light LS.

  When safety is ensured, the optical path length difference can be changed by moving the face of the subject in the z direction. For example, a chin receiving drive unit that moves the support unit 440 at least in the z direction under the control of the main control unit 211 may be provided. The chin rest drive may be movable in the xy direction.

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

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

DESCRIPTION OF SYMBOLS 1 Ophthalmology apparatus 2 Fundus camera unit 1A Optical system drive part 10 Illumination optical system 30 Shooting optical system 31 Focusing lens 41 Optical path length change part 41A, 114A Moving mechanism 42 Optical scanner 100 OCT unit 114 Corner cube 200 Arithmetic control unit 210 Control part 211 Main control unit 212 Storage unit 212a Corresponding information 220 Image forming unit 230 Data processing unit 231 Analysis unit 232 Distance specifying unit 240 User interface 241 Display unit 242 Operation unit 410 Base 420 Case 430 Lens housing unit 440 Support unit E Eye to be examined LS Measurement light LR Reference light LC Interference light

Claims (10)

An optical system for collecting data by scanning an area including at least a portion of the front surface of the subject's face using optical coherence tomography;
A drive unit that relatively moves the eye to be examined and the optical system in the optical axis direction of the optical system;
An analysis unit that identifies a first position corresponding to at least a part of the region based on the data collected by the optical system;
A control unit that relatively moves the eye to be examined and the optical system by controlling the drive unit based on the first position specified by the analysis unit;
Ophthalmic device. The optical system is
An objective lens;
The light from the light source is divided into reference light and measurement light, the measurement light is irradiated to the eye to be examined through the objective lens, and interference between the return light of the measurement light from the eye to be examined and the reference light An interference optical system for detecting light;
Including
The analysis unit identifies the first position based on a detection result of the interference light detected by the interference optical system;
The control unit includes the eye and the optical system based on the position of the objective lens, the first position, and the second position where the optical path length of the reference light and the optical path length of the measurement light coincide with each other. The ophthalmic apparatus according to claim 1, wherein the ophthalmologic apparatus is moved relatively. The control unit includes a first distance between the position of the objective lens and the second position, and a second between the position corresponding to the second position and the first position in the detection result of the interference light. The ophthalmologic apparatus according to claim 2, wherein the eye to be examined and the optical system are relatively moved based on a distance. The ophthalmologic according to claim 3, wherein the control unit relatively moves the eye to be examined and the optical system so that a sum of the first distance and the second distance becomes a predetermined working distance. apparatus. The interference optical system includes an optical path length changing unit that relatively changes the optical path length of the reference light and the optical path length of the measurement light,
The distance specifying unit that specifies the first distance based on an optical path length difference between the optical path of the reference light and the optical path of the measurement light that is changed by the optical path length changing unit. Item 5. The ophthalmic apparatus according to Item 4. The ophthalmic apparatus according to claim 5, wherein the optical path length changing unit includes a corner cube that is arranged in the optical path of the reference light or the optical path of the measurement light and is movable along the optical path. A storage unit that stores in advance correspondence information that associates the information corresponding to the optical path length difference with the first distance;
The ophthalmologic apparatus according to claim 5, wherein the distance specifying unit specifies the first distance based on the correspondence information stored in the storage unit. Including a photographing unit for photographing at least a part of the region;
The drive unit relatively moves the eye to be examined and the optical system in a direction intersecting an optical axis direction of the optical system;
The control unit moves the eye to be examined and the optical system relative to each other in a direction intersecting the optical axis direction of the optical system based on a captured image obtained by the imaging unit, and then moves the control unit to the first position. The ophthalmologic apparatus according to claim 1, wherein the eye to be examined and the optical system are relatively moved based on the optical axis direction. Including a support part for supporting the face;
The ophthalmologic apparatus according to any one of claims 1 to 8, wherein the driving unit relatively moves the support unit and the optical system. The ophthalmic apparatus according to any one of claims 1 to 9, wherein the optical system scans an area including a cornea, a heel, a nose, or a cheek.

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