JP2017184874A - Ophthalmic photographing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic photographing apparatus enabling adjustment of photographing condition associated with change of a fixation position to be correctly performed.SOLUTION: The ophthalmic photographing apparatus of the embodiment comprises: an image acquisition part; a fixation optical system; an optical system movement part; a first position detection part; and a control part. The image acquisition part includes an optical system for projecting a light to an eye to be examined and detecting a return light of the projected light, and acquires an image of the eye to be examined, from a detection result obtained by the optical system. The fixation optical system projects a fixation light flux according to a preset fixation position to the eye to be examined. The optical system movement part moves the optical system. The first position detection part detects a position of the eye to be examined. After the fixation optical system projects a fixation light flux according to a new fixation position to the eye to be examined, the first position detection part detects a position of the eye to be examined. The control part controls the optical system movement part based on the detected position.SELECTED DRAWING: Figure 3A

Description

  The present invention relates to an ophthalmologic photographing apparatus.

  Image diagnosis occupies an important position in the field of ophthalmology. For ophthalmologic image diagnosis, a fundus camera, a scanning laser ophthalmoscope (SLO), and a slit lamp microscope have been conventionally used. In recent years, optical coherence tomography (OCT) has been increasingly used. The fundus camera is a device that photographs the fundus with a digital camera. The SLO is an apparatus that forms an image by scanning the fundus at high speed with a weak laser beam. The slit lamp microscope is an apparatus for projecting slit light onto the anterior eye part and observing and photographing the projection surface (cross section) from an oblique direction. OCT is a technique for projecting measurement light onto the fundus or anterior eye, superimposing the return light with reference light to generate interference light, and forming an image from detection data of the interference light. OCT not only acquires B-mode images and three-dimensional images of the eye to be examined, but also constructs front images (en-face images) such as C-mode images and shadowgrams, constructs blood vessel-enhanced images (angiograms), It is also used for blood flow measurement and evaluation of eye tissue size and shape. Evaluation targets include axial length, corner angle, corneal thickness, retinal thickness, optic papilla shape, nerve running, and blood vessel running.

  In ophthalmologic image diagnosis, a wide range may be imaged or a plurality of parts may be imaged. Such imaging is realized by changing the fixation position of the eye to be examined. As a typical example, after the first imaging is executed in a state where the first fixation position is applied, the second imaging is executed after changing to the second fixation position. By repeating such processing as many times as desired, data of a plurality of ranges of the eye to be examined is collected. Note that the change of the fixation position is realized by changing the projection position of the fixation target.

  When the fixation position is changed, the eyeball rotates to capture the fixed fixation target in the fovea, and the alignment and focus states change. When the alignment state changes, there arises a problem that part or all of the light beam for fundus photographing is shifted to the iris, and the alignment must be performed again. Similarly, when the focus state changes, refocusing is required.

  In addition, when performing OCT of the fundus, if the alignment state is adjusted after changing the fixation position, the fundus that is the measurement object moves in the optical axis direction of the measurement light, so the measurement range in the optical axis direction (refer to the measurement optical path length and the reference) There arises a new problem that the fundus is out of the range of the measurement optical path in which the optical path length is substantially equal) or the measurement sensitivity is lowered.

  As a technique for solving the above problems, an OCT apparatus disclosed in Patent Document 1 is known. This OCT apparatus estimates the amount of alignment deviation and the amount of optical path length difference between the measurement light and the reference light from the estimated amount of rotation of the eye to be examined caused by the change of the fixation position, and based on the amount of deviation. Thus, it is configured to perform alignment adjustment and optical path length difference adjustment.

Japanese Patent No. 5836564

  However, considering that there are individual differences in the size of the eyeball and the position of the center of rotation, it is difficult to accurately determine the amount of deviation of the alignment and the optical path length difference from the change in the fixation position. In other words, when the invention according to Patent Document 1 is applied to actual photographing, there is a possibility that the photographing conditions cannot be accurately adjusted according to the change in the fixation position.

  An object of the ophthalmologic photographing apparatus according to the present invention is to accurately adjust photographing conditions accompanying a change in fixation position.

  The ophthalmologic photographing apparatus according to the embodiment includes an image acquisition unit, a fixation optical system, an optical system moving unit, a first position detecting unit, and a control unit. The image acquisition unit includes an optical system that projects light onto the eye to be examined and detects the return light, and obtains an image of the eye to be examined from the detection result obtained by the optical system. The fixation optical system projects a fixation light beam according to a preset fixation position onto the eye to be examined. The optical system moving unit moves the optical system. The first position detection unit detects the position of the eye to be examined. After the fixation optical system projects a fixation light beam corresponding to a new fixation position onto the eye to be examined, the first position detection unit detects the position of the eye to be examined. The control unit controls the optical system moving unit based on the detection position.

  According to the ophthalmologic photographing apparatus according to the embodiment, it is possible to accurately adjust the photographing condition accompanying the change in the fixation position.

Schematic showing the example of a structure of the ophthalmologic imaging device which concerns on embodiment. Schematic showing the example of a structure of the ophthalmologic imaging device which concerns on embodiment. Schematic showing the example of a structure of the ophthalmologic imaging device which concerns on embodiment. Schematic showing the example of a structure of the ophthalmologic imaging device which concerns on embodiment. The flowchart showing the example of operation | movement of the ophthalmologic imaging device which concerns on embodiment.

  Exemplary embodiments of the present invention will be described in detail with reference to the drawings. The ophthalmologic imaging apparatus according to the embodiment includes an optical system for acquiring an image of an eye to be examined, and includes, for example, any one of an OCT apparatus, a fundus camera, an SLO, and the like. Hereinafter, an example in which the swept source OCT and the fundus camera are combined will be described, but the embodiment is not limited thereto. For example, spectral domain OCT using a low-coherence light source and a spectroscope can be employed instead of the swept source OCT.

<Constitution>
As shown in FIG. 1, the ophthalmologic photographing apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 is provided with an optical system and mechanism for acquiring a front image of the eye E (anterior eye portion Ea, fundus oculi Ef). The OCT unit 100 is provided with an optical system and a mechanism for performing OCT. The arithmetic control unit 200 includes a processor that executes various arithmetic operations and controls. In addition to these, a member for supporting the subject's face (a chin rest, a forehead rest, etc.) and a lens unit (for example, an anterior segment OCT attachment) for switching an OCT target site are provided. Furthermore, the ophthalmologic photographing apparatus 1 includes a pair of anterior eye cameras 5A and 5B.

  In this specification, the “processor” is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), or a programmable logic device (eg, SPLD (Simple ProLigL). It means a circuit such as Programmable Logic Device (FPGA) or Field Programmable Gate Array (FPGA). For example, the processor implements the functions according to the embodiment by reading and executing a program stored in a storage circuit or a storage device.

<Fundus camera unit 2>
The fundus camera unit 2 is provided with an optical system for photographing the anterior segment Ea and the fundus oculi Ef. The acquired image is a front image such as an observation image or a captured image. The observation image is obtained by moving image shooting using near infrared light. The photographed image is a still image using flash light.

  The fundus camera unit 2 includes an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the eye E with illumination light. The imaging optical system 30 detects the return light of the illumination light from the eye E. The measurement light from the OCT unit 100 is guided to the eye E through the optical path in the fundus camera unit 2, and the return light is guided to the OCT unit 100 through the same optical path.

  The observation light source 11 of the illumination optical system 10 outputs continuous light (observation illumination light) including a near infrared component. The observation illumination light is reflected by the reflecting mirror 12 having a curved reflecting surface, passes through the condensing lens 13 and passes through the visible cut filter 14 to become near infrared light. 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 by the peripheral part of the aperture mirror 21 (region around the aperture part), passes through the dichroic mirror 46, is refracted by the objective lens 22, and is inspected by the eye E (anterior eye part Ea or Illuminate the fundus oculi Ef). The return light of the observation illumination light from the eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central region of the perforated mirror 21, and passes through the dichroic mirror 55. The light is reflected by the mirror 32 via the photographing focusing lens 31. Further, the return light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and forms an image on the light receiving surface of the image sensor 35 by the condenser lens. The image sensor 35 detects return light at a predetermined frame rate. Note that the focus of the photographing optical system 30 is adjusted with respect to the fundus oculi Ef or the anterior eye segment.

  The imaging light source 15 outputs flash light (imaging illumination light) including a visible component (and a near infrared component). The imaging illumination light is applied to the fundus oculi Ef through the same path as the observation illumination light. The return light of the imaging illumination light from the eye E is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is reflected by the condenser lens 37. An image is formed on the light receiving surface of the image sensor 38.

  The LCD 39 displays a fixation target and a visual acuity measurement target. A part of the light beam (fixed light beam or the like) output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, and passes through the photographing focusing lens 31 and the dichroic mirror 55, and then the aperture mirror 21 Pass through the hole. The light beam that has passed through the aperture of the aperture mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus oculi Ef.

  The change of the fixation position is realized by changing the display position of a bright spot or the like on the LCD 39. The display position of bright spots and the like is controlled by a main control unit 211 described later. The main control unit 211 displays a bright spot or the like at the screen position of the LCD 39 corresponding to the fixation position set by a predetermined method. The method for setting the fixation position is performed using, for example, a user interface 240 described later. Moreover, it can also be configured to display a bright spot or the like at a predetermined position according to the photographing mode (macular mode, nipple mode, panoramic mode, etc.).

  The alignment optical system 50 generates an alignment index used for alignment of the optical system with respect to the eye E. The alignment light output from the LED 51 passes through the apertures 52 and 53 and the relay lens 54, is reflected by the dichroic mirror 55, and passes through the hole 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 eye E by the objective lens 22. The return light of the alignment light (corneal reflection light, fundus reflection light, etc.) is guided to the image sensor 35 through the same path as the return light of the observation illumination light. Manual alignment and auto-alignment can be executed based on the received light image (alignment index image).

  The focus optical system 60 generates a split index used for focus adjustment with respect to the eye E. The focus optical system 60 is moved along the optical path (illumination optical path) of the illumination optical system 10 in conjunction with the movement of the imaging focusing lens 31 along the optical path (imaging optical path) of the imaging optical system 30. The reflection bar 67 can be inserted into and removed from the illumination optical path. When performing the focus adjustment, the reflecting surface of the reflecting bar 67 is inclinedly arranged in the illumination optical path. The focus light output from the LED 61 passes through the relay lens 62, is separated into two light beams by the split indicator plate 63, passes through the two-hole aperture 64, is reflected by the mirror 65, and is reflected by the condenser lens 66 as a reflecting rod 67. The light is once imaged and reflected on the reflection surface. 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 guided to the image sensor 35 through the same path as the return light of the alignment light. Manual focusing and autofocusing can be executed based on the received light image (split index image).

  The diopter correction lenses 70 and 71 can be selectively inserted into a photographing optical path between the perforated mirror 21 and the dichroic mirror 55. The diopter correction lens 70 is a plus lens (convex lens) for correcting the intensity hyperopia. The diopter correction lens 71 is a minus lens (concave lens) for correcting intensity myopia.

  The dichroic mirror 46 combines the fundus imaging optical path and the OCT optical path. The dichroic mirror 46 reflects light in a wavelength band used for OCT and transmits light for fundus photographing. In the optical path for OCT, 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 provided in this order from the OCT unit 100 side.

  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 for OCT. This change in optical path length is used for optical path length correction according to the axial length, adjustment of the interference state, and the like. The optical path length changing unit 41 includes a corner cube and a mechanism for moving the corner cube.

  The optical scanner 42 is disposed at a position optically conjugate with the pupil of the eye E. The optical scanner 42 deflects the measurement light LS passing through the optical path for OCT. The optical scanner 42 is, for example, a galvano scanner capable of two-dimensional scanning.

  The OCT focusing lens 43 is moved along the optical path of the measurement light LS in order to adjust the focus of the OCT optical system. The movement of the photographing focusing lens 31, the movement of the focus optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

  The ophthalmologic photographing apparatus 1 includes an auxiliary lens unit 80 that can be disposed on the front side (the eye E side) of the objective lens 22. The auxiliary lens unit 80 includes, for example, a lens group having a positive refractive power. The auxiliary lens unit 80 is retracted from the optical path when performing OCT of the fundus oculi Ef, and is inserted into the optical path when performing OCT of the anterior segment Ea. The movement of the auxiliary lens unit 80 (insertion and removal from the optical path) is performed electrically or manually.

<Anterior Eye Cameras 5A and 5B>
The anterior eye cameras 5A and 5B are used to obtain the relative position between the optical system of the ophthalmologic photographing apparatus 1 and the eye E as in the invention disclosed in Japanese Patent Laid-Open No. 2013-248376. The anterior eye cameras 5A and 5B are provided on the surface on the eye E side of a housing (such as the fundus camera unit 2) in which an optical system is stored. The ophthalmologic photographing apparatus 1 analyzes two anterior eye images acquired substantially simultaneously from different directions by the anterior eye cameras 5A and 5B, thereby obtaining a three-dimensional image between the optical system and the eye E to be examined. Find the relative position. The analysis of the two anterior segment images may be the same as the analysis disclosed in JP2013-248376A. Further, the number of anterior eye camera may be any number of 2 or more.

  In this example, the position of the eye E (that is, the relative position between the eye E and the optical system) is obtained using two or more anterior eye cameras, but a method for obtaining the position of the eye E is as follows. It is not limited to this. For example, the position of the eye E can be obtained by analyzing a front image of the eye E (for example, an observation image of the anterior segment Ea). Alternatively, means for projecting an index on the cornea of the eye E can be provided, and the position of the eye E can be obtained based on the projected position of the index (that is, the detection state of the corneal reflected light flux of the index).

<OCT unit 100>
As illustrated in FIG. 2, the OCT unit 100 is provided with an optical system for executing the swept source OCT. This optical system divides the light from the wavelength tunable light source (wavelength sweep type light source) into measurement light and reference light, and superimposes 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 and detects the interference light. A detection result (detection signal) obtained by the interference optical system is sent to the arithmetic control unit 200.

  The light source unit 101 includes, for example, a near-infrared wavelength variable laser that changes the wavelength of emitted light at high speed. 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. Further, the light L0 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 converted into a parallel light beam, and 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 acts to match the optical path length of the reference light LR and the optical path length of the measurement light LS. The dispersion compensation member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS. The corner cube 114 is movable in the incident direction of the reference light LR, and thereby the optical path length of the reference light LR is changed.

  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 to 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 its polarization state is adjusted. The reference light LR is guided to the attenuator 120 by the optical fiber 119 and the amount of light is adjusted, and is guided to the fiber coupler 122 by the optical fiber 121. It is burned.

  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, and the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, and the mirror 44. Then, the light passes through the relay lens 45, is reflected by the dichroic mirror 46, is refracted by the objective lens 22, and enters the eye E to be examined. When OCT of the anterior segment Ea is performed, the measurement light LS refracted by the objective lens 22 is further refracted by the lens group in the auxiliary lens unit 80 and irradiated to the anterior segment Ea. The measurement light LS is scattered and reflected at various depth positions of the fundus oculi Ef or the anterior segment Ea. The return light of the measurement light LS from the eye E 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 generates a pair of interference light LC by branching the interference light at a predetermined branching ratio (for example, 1: 1). The pair of interference lights LC are guided to the detector 125 through optical fibers 123 and 124, respectively.

  The detector 125 is, for example, a balanced photodiode. The balanced photodiode has a pair of photodetectors that respectively detect the pair of interference lights LC, and outputs a difference between detection results obtained by these. The detector 125 sends this output (detection 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 that is swept within a predetermined wavelength range by the wavelength variable light source 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 signal input from the detector 125 based on the clock KC. The DAQ 130 sends the sampling result of the detection signal from the detector 125 to the arithmetic control unit 200.

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

  The polarization controllers 103 and 118 have a known configuration. For example, the polarization controller 103 (118) includes one or more winding portions around which a part of the optical fiber is wound, and a rotation mechanism that rotates each winding portion. Alternatively, the polarization controller 103 (118) may include the following elements: a collimator lens that converts light once emitted from the optical fiber into a parallel light beam; a first 1/1 sequentially disposed in the optical path of the parallel light beam. 4-wavelength plate (λ / 4 plate), 1 / 2-wavelength plate (λ / 2 plate), and second 1 / 4-wavelength plate; the parallel light flux that has passed through the second 1 / 4-wavelength plate is directed toward the end of the optical fiber. A collimator lens for focusing the light; a rotation mechanism for rotating the first quarter-wave plate, the half-wave plate, and the second quarter-wave plate, respectively. Each of the polarization controllers 103 and 118 is controlled by the main control unit 211.

<Control system>
A configuration example of the control system of the ophthalmologic photographing apparatus 1 is shown in FIGS. 3A and 3B. The control unit 210, the image forming unit 220, and the data processing unit 230 are included in the arithmetic control unit 200.

<Control unit 210>
The control unit 210 executes various controls. The control unit 210 includes a main control unit 211 and a storage unit 212. Control unit 210 includes a processor.

<Main control unit 211>
The main control unit 211 controls each unit of the ophthalmologic photographing apparatus 1 (including the elements shown in FIGS. 1 to 3B). 3A moves the imaging focusing lens 31, the OCT focusing driving unit 43A moves the OCT focusing lens 43, and the reference driving unit 114A moves the corner cube 114.

  The optical system moving unit 150 moves at least a part of the optical system provided in the ophthalmologic photographing apparatus 1. As a typical example, the optical system moving unit 150 is configured to move the fundus camera unit 2 three-dimensionally. In this case, the optical system moving unit 150 includes, for example, one or more movable tables on which the fundus camera unit 2 is mounted, a horizontal direction (left and right direction, x direction), a vertical direction (y direction), and a front and rear direction (objective). And one or more actuators for moving the movable table in the optical axis direction and the z direction).

<Storage unit 212>
The storage unit 212 stores various data. Examples of data stored in the storage unit 212 include an OCT image, an anterior ocular segment image, a fundus image, and eye information to be examined. The eye information includes subject information such as patient ID and name, left / right eye identification information, electronic medical record information, and the like.

<Image forming unit 220>
The image forming unit 220 forms an image based on the output from the DAQ 130 (sampling result of the detection signal). For example, the image forming unit 220 forms a reflection intensity profile for each A line by performing signal processing on the spectrum distribution based on the sampling result for each A line as in the case of the conventional swept source OCT (A scan, A Called a scanned image). This signal processing includes noise removal (noise reduction), filter processing, FFT (Fast Fourier Transform), and the like. Furthermore, the image forming unit 220 forms a cross-sectional image along the arrangement of the plurality of A lines by imaging the plurality of A line profiles corresponding to the plurality of A lines and arranging them along the scan lines (B Called scan, B-scan image, etc.). The image forming unit 220 includes a processor.

<Data processing unit 230>
The data processing unit 230 executes various data processing. As a typical example, the data processing unit 230 processes images (fundus images, anterior eye images, etc.) acquired by the fundus camera unit 2, processes images acquired by the anterior eye cameras 5A and 5B, and an image forming unit. Processing of the image formed by 220 is executed. These processes include at least one of various image processes and various analysis processes. For example, the data processing unit 230 performs creation of 3D image data (stack data, volume data, etc.) based on OCT raster scan data, rendering of 3D image data, image correction, image analysis based on an analysis application, and the like. The data processing unit 230 includes a processor.

  The data processing unit 230 includes a first alignment processing unit 231, a second alignment processing unit 232, a focusing processing unit 233, and an optical path length adjustment processing unit 234. These processing units 231 to 234 execute processing for adjusting the imaging condition to the displacement (rotation) of the eye E to be examined accompanying the change of the fixation position. In this embodiment, after moving the fixation position, the position of the eye to be examined is detected to perform rough alignment (coarse alignment), and then finer alignment (alignment fine adjustment), focusing, and optical path length adjustment Execute. The first alignment processing unit 231 executes processing related to coarse alignment, the second alignment processing unit 232 executes processing related to fine alignment, the focusing processing unit 233 executes processing related to focusing, and the optical path length adjustment processing unit 234. Performs processing related to optical path length adjustment.

  In a typical example of the present embodiment, after a fixation light beam corresponding to the changed fixation position is projected onto the eye E, the pair of anterior eye cameras 5A and 5B capture the eye E substantially simultaneously. . A pair of anterior eye images acquired by the pair of anterior eye cameras 5A and 5B (which may be a plurality of pairs of anterior eye images acquired in time series) is an object that is displaced as the fixation position is changed. It is used to obtain the position (three-dimensional position) of the optometry E. The optical system is moved to a position corresponding to the obtained three-dimensional position of the eye E (coarse alignment), and then fine alignment, focusing, and optical path length adjustment are performed.

<First alignment processing unit 231>
The first alignment processing unit 231 performs data processing related to rough alignment. For example, the first alignment processing unit 231 analyzes the pair of anterior eye images acquired substantially simultaneously by the pair of anterior eye cameras 5A and 5B, thereby allowing the eye E to be examined after the fixation position is changed. A position (for example, a relative position with respect to the ophthalmologic photographing apparatus 1) is obtained. This processing includes, for example, arithmetic processing using trigonometry based on the positional relationship between the pair of anterior eye cameras 5A and 5B and the eye E as described in Japanese Patent Application Laid-Open No. 2013-248376.

  The main control unit 211 moves the optical system based on the position of the eye E obtained by the first alignment processing unit 231 so that the optical system (for example, the fundus camera unit 2) and the eye E to be examined have a predetermined positional relationship. The unit 150 is controlled. Here, the predetermined positional relationship is a positional relationship in which imaging or examination of the eye E can be performed using the optical system. As a typical example, when the three-dimensional position (x coordinate, y coordinate, z coordinate) of the eye E is obtained by the first alignment processing unit 231, the x coordinate and y coordinate of the optical axis of the objective lens 22 are the eye E to be examined. And the position where the difference between the z coordinate of the objective lens 22 (front lens surface) and the z coordinate of the eye E (corneal surface) is equal to a predetermined distance (working distance). , Set as the movement destination of the optical system. The same process can be executed when any one or more of these three-dimensional coordinates are referred to.

<Second alignment processing unit 232>
The second alignment processing unit 232 executes data processing related to fine alignment adjustment performed after the rough alignment. The alignment fine adjustment is executed with an accuracy higher than the coarse alignment. Therefore, the detection accuracy of the position of the eye E in the alignment fine adjustment is set to be equal to or higher than the position detection accuracy in the rough alignment. In other words, the position detection in the fine alignment adjustment is executed with the same accuracy as the position detection in the coarse alignment or higher accuracy than that.

  The position detection in the rough alignment and the position detection in the alignment fine adjustment are performed using the same element (means) or are performed using different elements. If the same element is used for both alignments, the detection accuracy of this element may be switched. For example, the position detection for the coarse alignment may be performed with the first accuracy, and the position detection for the alignment fine adjustment may be performed with the second accuracy higher than the first accuracy. Is possible. When the same element is used for both alignments, the first alignment processing unit 231 and the second alignment processing unit 232 may be the same element (such as a processor).

  As a typical example, the position detection in the rough alignment includes one of the following elements: (1-1) Two or more imaging units (eg, a pair of imaging units) for imaging the eye E from different directions Anterior eye camera 5A and 5B); (1-2) Front image acquisition unit (for example, illumination optical system 10 and imaging optical system 30 for acquiring observation images) for imaging eye E to be examined from the front; 1-3) An index optical system that projects an index beam onto the cornea of the eye E and detects a reflected beam from the cornea. The combination of each of (1-1), (1-2), and (1-3) and the first alignment processing unit 231 is an example of a first position detection unit. In the present embodiment, (1-1) is applied. (1-2) and (1-3) will be described later.

  As a typical example, the position detection in the alignment fine adjustment includes any of the following elements: (2-1) Two or more imaging units for imaging the eye E from different directions (examples) (A pair of anterior eye cameras 5A and 5B); (2-2) means for projecting an alignment index onto the eye E (example: alignment optical system 50) and the eye E onto which the alignment index is projected Means (example: photographing optical system 30). Here, (2-1) is the same element as (1-1). (2-2) is an element different from any of (1-1), (1-2), and (1-3). A combination of each of (2-1) and (2-2) and the second alignment processing unit 232 is an example of a second position detection unit.

  In the present embodiment, (2-1) or (2-2) is applied. When (2-1) is applied, the second alignment processing unit 232 includes a pair of anterior eye cameras 5A and 5B, similar to the first alignment processing unit 231 when (1-1) is applied. The position (three-dimensional position) of the eye E is obtained by executing arithmetic processing using trigonometry based on the positional relationship with the eye E. On the other hand, when (2-2) is applied, an alignment index is projected onto the eye E and the return light is detected by the image sensor 35 as in general auto alignment. The second alignment processing unit 232 extracts the alignment index image from the output signal from the image sensor 35, and calculates the displacement of the alignment index image with respect to a predetermined alignment mark (for example, a parenthesis mark arranged at the center of the frame). The calculated displacement is used as the position of the eye E.

  After the optical system moving unit 150 is controlled based on the position of the eye E obtained by the first alignment processing unit 231, the second alignment processing unit 232 detects the position of the eye E. The main control unit 211 controls the optical system moving unit 150 based on the position detected by the second alignment processing unit 232. Thereby, the position of the optical system is adjusted so that the optical system and the eye E to be examined have the predetermined positional relationship described above.

<Focus processing unit 233>
The focusing processing unit 233 executes data processing related to focusing. The ophthalmologic photographing apparatus 1 according to the present embodiment includes a focusing function in a fundus camera (fundus photographing) and a focusing function in OCT. Focusing in the fundus camera includes, for example, a photographing focus lens 31 of the photographing optical system 30, a photographing focus driving unit 31A for moving the photographing focusing lens 31, and a main control unit that controls the photographing focus driving unit 31A. 211 and the focusing processing unit 233 are executed. The focusing in the OCT is, for example, the OCT focusing lens 43 in the measurement optical path, the OCT focusing driving unit 43A for moving the OCT focusing lens 43, and the main control unit 211 that controls the OCT focusing driving unit 43A. And a focusing processing unit 233. Both focusing may be performed in a coordinated manner or independently of each other.

  In focusing, first, processing for grasping the current focus state is executed. This process is executed using, for example, a split index. That is, as is generally performed, the focusing processing unit 233 extracts a pair of split index images by analyzing an observation image of the fundus oculi Ef on which the split index is projected, and a pair of split indices. The relative deviation of is calculated. The calculated shift (shift direction, shift amount) reflects the current focus state. The main control unit 211 controls the imaging focus drive unit 31A and the OCT focus drive unit 43A based on the calculated deviation.

  In another typical example, the current focus state can be grasped using OCT. The process using OCT is performed as follows, for example. First, OCT is repeatedly performed on substantially the same cross section of the fundus oculi Ef (live scan). Thereby, the moving image (OCT moving image) of this cross section is taken. The frame rate of the OCT moving image corresponds to the OCT repetition frequency. As a first method, manual focusing is possible by displaying an OCT moving image on the display unit 241.

  As a second technique, the focusing processing unit 233 performs the following processing, thereby enabling autofocusing. The focus processing unit 233 analyzes a pixel value (luminance value) of a still image constituting the OCT moving image to identify a high image quality region (high image quality region), and further, a depth direction (z direction) of the frame The current focus position can be specified based on the position (z coordinate) of the high-quality area at. When the tissue of the fundus oculi Ef to be focused (the fundus surface, the retinal pigment epithelium layer, the ganglion cell layer, the nerve fiber layer, the choroid, etc.) has already been determined, the focusing processing unit 233 applies the tissue to the tissue in the still image. The corresponding area (target area) is specified. Alternatively, the user may specify the target area. The focus processing unit 233 obtains the position (z coordinate) of the target area in the depth direction (z direction) of the frame. The main control unit 211 generates a control signal for moving the current focal position of the OCT optical system to a position corresponding to the target area, and sends the control signal to the OCT focusing drive unit 43A. Thereby, the focus position of the measurement light LS can be adjusted to the target area. The main control unit 211 can execute control of the imaging focus drive unit 31A in conjunction with control of the OCT focus drive unit 43A.

  Another example of focusing using OCT will be described. In this example, focusing is performed based on OCT measurement sensitivity (interference sensitivity). For example, it is possible to determine the position of the OCT focusing lens 43 that maximizes the interference intensity while monitoring the intensity of the interference signal obtained by OCT (interference intensity). The main control unit 211 places the OCT focusing lens 43 at this position. Further, the main control unit 211 moves the imaging focusing lens 31 to a position corresponding to the position of the OCT focusing lens 43.

<Optical path length adjustment processing unit 234>
As described above, the ophthalmologic photographing apparatus 1 according to the present embodiment includes the optical path length changing unit 41 for changing the optical path length of the measurement light LS, the corner cube 114 for changing the optical path length of the reference light LR, and the reference. And a drive unit 114A. In general, at least one of an element for changing the optical path length of the measurement light and an element for changing the optical path length of the reference light is provided. In other words, an element for changing the difference between the length of the measurement optical path and the length of the reference optical path is provided.

  The optical path length adjustment processing unit 234 executes a process for calculating a deviation in optical path length between the measurement optical path and / or the reference optical path. The deviation of the optical path length is expressed as a displacement with respect to a predetermined position (reference position) in the optical axis direction (z direction) of the optical path of the measurement light LS, for example. This reference position is typically set to a z position that passes through the central position of the OCT imaging range or its vicinity. The main control unit 211 controls the optical path length changing unit 41 and / or the reference driving unit 114A so as to cancel out the deviation calculated by the optical path length adjustment processing unit 234.

  As described above, in the optical path length difference adjustment, the optical path length changing unit 41 and / or the reference driving unit 114A is drawn so that the predetermined part (reference part) of the eye E to be examined is drawn at the predetermined z position in the frame of the OCT image. Is controlled. Thereby, the optical path length difference between the measurement optical path and the reference optical path is adjusted. As the reference part, a part exhibiting characteristic luminance in the OCT image (or a part exhibiting characteristic reflection intensity in the reflection intensity profile) is set in advance. As a specific example, the retinal pigment epithelium layer can be set as a reference in OCT measurement of the fundus oculi Ef, and the corneal surface can be set as a reference in OCT measurement of the anterior segment. Such automatic processing for searching for a suitable optical path length difference is called auto-Z.

  The optical path length difference adjustment is not limited to auto Z. For example, an automatic process for maintaining a suitable image rendering position achieved by auto-Z can be applied. Such processing is called Z-lock. In the Z lock, for example, the optical path length changing unit 41 is controlled such that the state where the reference portion for adjusting the optical path length difference is depicted at a predetermined z position in the frame is maintained.

<Polarization adjustment processing unit 235>
The polarization characteristics of the fundus oculi Ef vary from site to site. For example, the polarization characteristics of the optic disc (and the vicinity thereof) are different from the polarization characteristics of the macula (and the vicinity thereof). Therefore, in order to improve the image quality of the OCT image, it is desirable to control the polarization state according to the imaging region. In this example, the polarization controller 118 controls the polarization state of the reference light LR. However, a polarization controller for controlling the polarization state of the measurement light LS may be arranged in the measurement optical path. Further, a polarization controller may be arranged in both the reference optical path and the measurement optical path.

  The main control unit 211 repeatedly executes the OCT scan while controlling the polarization controller 118. The polarization adjustment processing unit 235 analyzes the sequentially acquired OCT images and calculates an evaluation value of the image quality. The image quality evaluation value may be an arbitrary image quality parameter such as contrast. The main control unit 211 controls the polarization controller 118 based on the image quality evaluation values calculated sequentially. That is, the main control unit 211 searches for a polarization state in which the image quality evaluation value is optimized by feeding back the sequentially calculated image quality evaluation value to the control of the polarization controller 118.

<User Interface 240>
The user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes the display device 3. The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device such as a touch panel in which a display function and an operation function are integrated. Embodiments that do not include at least a portion of the user interface 240 can also be constructed. For example, the display device may be an external device connected to the ophthalmologic photographing apparatus.

<Operation>
The operation of the ophthalmologic photographing apparatus 1 will be described. An example of the operation is shown in FIG.

(S1: Start of macular mode)
First, preparation for shooting is performed. The examiner activates the ophthalmologic photographing apparatus 1 and selects a desired photographing mode. In this example, a case where the macular mode and the nipple mode are applied in this order will be described. The macular mode is an imaging mode for imaging the macula and its surrounding area (OCT scan), and the nipple mode is an imaging mode for imaging the optic nerve head and its surrounding area. The face of the subject is fixed by a chin rest and a forehead rest.

  In response to the predetermined operation, the main control unit 211 starts processing related to the macular mode. The main control unit 211 controls the LCD 39 to display a bright spot at a predetermined position corresponding to the macular mode. Thereby, a fixation light flux corresponding to a fixation position for photographing the macula and its peripheral region is projected onto the eye E.

(S2: execution of auto alignment)
The main control unit 211 performs auto alignment. Auto-alignment is performed in the same manner as before by using a pair of anterior eye cameras 5A and 5B or an alignment index.

(S3: Optimization of OCT conditions)
Next, the ophthalmologic imaging apparatus 1 executes a process for optimizing the OCT condition. This optimization process includes, for example, focusing, optical path length adjustment, and polarization adjustment. Focusing and optical path length adjustment are performed as described above. The optimization process may include adjustment of the light amount (for example, control of the attenuator 120).

(S4: OCT scan of macular)
After the optimization process is completed, the main control unit 211 controls the OCT unit 100, the optical scanner 42, and the like, thereby executing an OCT scan (for example, raster scan) of the macula and its surrounding area. The image forming unit 220 forms a plurality of B scan images based on data collected by the raster scan. The data processing unit 230 creates three-dimensional image data based on a plurality of B scan images.

(S5: Switch to nipple mode)
After completion of the macular OCT scan, the macular mode ends. The main control unit 211 causes the display unit 241 to display a graphical user interface (GUI) including an icon of the next imaging mode (imaging site or the like). The examiner selects a desired imaging mode. In this example, the nipple mode is selected. When another shooting mode is selected, processing according to the shooting mode is executed. If the imaging mode is not selected for a certain period of time, the imaging of the subject or the eye is completed.

(S6: Change of fixation position)
When the nipple mode is selected, the main control unit 211 controls the LCD 39 to display a bright spot at a predetermined position corresponding to the nipple mode. As a result, a fixation light flux corresponding to the fixation position for photographing the optic disc and the surrounding area is projected onto the eye E.

(S7: Capture of a pair of anterior segment images)
The main controller 211 captures a pair of anterior eye images acquired by the anterior eye cameras 5A and 5B substantially simultaneously after the fixation position is changed. The main control unit 211 sends the pair of captured anterior eye image to the data processing unit 230.

(S8: Detection of eye position)
The first alignment processing unit 231 obtains the position of the eye E after the fixation position is changed by analyzing the pair of anterior eye images input from the main control unit 211. This analysis process includes, for example, a process of extracting a pupil region from each anterior eye image, a process of obtaining the center of gravity or center of the pupil area, and the 3 of the eye E to be examined based on the obtained positions of the pair of pupil centers of gravity. Processing for calculating a dimension position.

(S9: Coarse alignment)
The main control unit 211 controls the optical system moving unit 150 based on the three-dimensional position of the eye E detected in step S8 so that the fundus camera unit 2 and the eye E are in a predetermined positional relationship. As described above, this predetermined positional relationship is such that the x-coordinate and y-coordinate of the optical axis of the objective lens 22 coincide with the x-coordinate and y-coordinate of the eye E, respectively, and the objective lens 22 (front lens surface). The positional relationship is such that the difference between the z coordinate and the z coordinate of the eye E (corneal surface) is equal to a predetermined distance (working distance).

(S10: Fine alignment adjustment)
After the rough alignment is completed, the main control unit 211 and the second alignment processing unit 232 perform alignment fine adjustment in the manner described above.

(S11: Focusing)
After the alignment fine adjustment is completed, the main control unit 211 and the focusing processing unit 233 perform focusing in the manner described above.

(S12: Optical path length adjustment)
After the focusing is completed, the main control unit 211 and the optical path length adjustment processing unit 234 perform the optical path length adjustment as described above.

(S13: Polarization adjustment)
After completing the optical path length adjustment, the main control unit 211 and the polarization adjustment processing unit 235 perform the optical path length adjustment in the manner described above.

(S14: OCT scan of nipple)
After completing the processing (optimization processing) in steps S10 to S13, the main control unit 211 controls the OCT unit 100, the optical scanner 42, and the like to perform an OCT scan (for example, raster scan) of the optic nerve head and its surrounding area. Run. The image forming unit 220 forms a plurality of B scan images based on data collected by the raster scan. The data processing unit 230 creates three-dimensional image data based on a plurality of B scan images.

  Furthermore, when performing the OCT scan of another site | part, the process similar to step S5-S14 is repeated. In addition, photographing of the eye of the eye E is performed as necessary. When the imaging of the subject is completed, the main control unit 211 stores the acquired image and data in a medical image archiving apparatus (not shown) or the like. The process according to this example ends here.

<Modification>
Several modifications of the above embodiment will be described.

(About coarse alignment)
In the above embodiment, as shown in (1-1) above, coarse alignment is performed using two or more imaging units (eg, a pair of anterior eye cameras 5A and 5B) for imaging the eye to be examined from different directions. The configuration for executing is described. Hereinafter, a case where the following configuration is applied will be described: (1-2) Front image acquisition unit for imaging the eye E to be examined from the front (example: illumination optical system 10 and imaging optics for acquiring an observation image) System 30); (1-3) An index optical system that projects an index beam onto the cornea of the eye E and detects a reflected beam from the cornea.

  (1-2) When a front image acquisition unit for photographing the eye E from the front is applied, for example, a process for specifying the pupil region in the observation image of the anterior eye part Ea and its center of gravity or center are specified. Processing, processing for calculating a displacement between the position of the center of gravity and the like and the center of the frame (the optical axis position of the photographing optical system 30), and controlling the optical system moving unit 150 so as to cancel the displacement, the fundus camera unit 2 and the like The process of moving is performed. In this example, the positions in the x direction and the y direction are referred to.

  (1-3) When an index optical system that projects an index beam onto the cornea of the eye E and detects a reflected beam from the cornea is applied, for example, the index is applied to the cornea from a direction different from the optical axis of the imaging optical system 30. A projection system for projecting a light beam and a light receiving system arranged in a direction symmetrical to the projection system with respect to the optical axis of the photographing optical system 30 are provided. The projection system includes, for example, a light source and a condenser lens. The image of the index light beam projected onto the cornea is, for example, a bright spot image or a ring image. The light receiving system includes, for example, an imaging lens, an image sensor, and the like, and detects the reflected light beam of the index light beam projected onto the cornea by the projection system. An output signal from the image sensor is input to the main control unit 211. The first alignment processing unit 231 specifies the pixel of the image sensor that detects the reflected light beam of the index light beam based on the output signal from the image sensor, and obtains the position of the eye E based on the position of this pixel. When a ring image or the like is projected onto the cornea, the position of the pixel corresponding to the center of gravity or center of the ring image detected by the image sensor is obtained, and the position of the eye E is obtained based on the position of this pixel. it can.

  Any one or more of (1-1), (1-2) and (1-3) can be combined. Moreover, you may perform rough alignment using structures other than these. It is also possible to combine any two or more of (1-1), (1-2), (1-3) and other configurations.

  Another method of coarse alignment (and / or fine alignment) will be described. In this example, the fundus camera unit 2 (the illumination optical system 10 and the photographing optical system 30) is used to acquire a live image of the anterior segment Ea, and the first alignment processing unit 231 uses the size (area, pupil) of the pupil region in each frame. The position of the fundus camera unit 2 is changed stepwise or continuously. Thereby, the size of the pupil region changes in time series. It is considered that the size of the pupil region is maximized when the optical axis of the photographing optical system 30 coincides with the center of gravity (center) of the pupil. Therefore, coarse alignment can be performed by searching for the position of the fundus camera unit 2 that maximizes the size of the pupil region using the main control unit 211, the first alignment processing unit 231, and the like.

  Still another method will be described. In this example, a live image of the anterior segment Ea is acquired using the pair of anterior segment cameras 5A and 5B. That is, the pair of anterior eye cameras 5A and 5B repeatedly execute substantially simultaneous imaging at a predetermined time interval (frame rate). A pair of frames (anterior segment image) acquired substantially simultaneously are sequentially sent to the first alignment processing unit 231. The first alignment processing unit 231 calculates the size (area, diameter, etc.) of the pupil region in each of the pair of frames. The relationship between the sizes of the pupil regions in the pair of frames is affected by the positional relationship between the pair of anterior eye cameras 5A and 5B. For example, when the pair of anterior eye cameras 5A and 5B are arranged at positions (directions) symmetrical with respect to the optical axis of the photographing optical system 30, the optical axis of the photographing optical system 30 is the center of gravity (center) of the pupil. Are equal to each other, the sizes of the pupil regions in the pair of frames are considered to be equal. Therefore, coarse alignment can be performed by searching for the position of the fundus camera unit 2 such that the sizes of the pupil regions in the pair of frames are equal using the main control unit 211, the first alignment processing unit 231, and the like.

(About panorama shooting)
The panorama shooting is a shooting mode in which a plurality of regions of the fundus oculi Ef are sequentially shot and a plurality of acquired images are combined to construct a wide area image (panoramic image). The configuration and operation of the ophthalmologic photographing apparatus 1 can be applied to panoramic photographing. In panoramic photography, first, an OCT scan of the first region of the fundus oculi Ef is executed while projecting a fixation light beam corresponding to the first fixation position. After completion of the OCT scan of the first area, a fixation light beam corresponding to the second fixation position is projected, coarse alignment, fine alignment adjustment, focusing, optical path length adjustment, etc. are executed, and the OCT scan of the second area is executed. Is done. Similarly, after completion of imaging of the mth area, a fixation light beam corresponding to the (m + 1) th fixation position is projected, coarse alignment, fine alignment adjustment, focusing, optical path length adjustment, etc. are performed, and an OCT scan of the (m + 1) th area is performed. Is executed. This series of processes is repeated until the OCT scan of a plurality of areas is completed. The OCT scan of each region is, for example, a raster scan. The data processing unit 230 forms a plurality of three-dimensional images from a plurality of OCT scan data corresponding to a plurality of regions, and combines these three-dimensional images to provide a single three-dimensional representing a range including the plurality of regions. Form an image.

(About other modalities)
In fundus photography using SLO, the same processing as described above can be applied. For example, in panoramic photography using SLO, an SLO scan of the first region of the fundus oculi Ef is executed while projecting a fixation light beam corresponding to the first fixation position. After the SLO scan of the first area is completed, a fixation light beam corresponding to the second fixation position is projected, coarse alignment, fine alignment, focusing, etc. are executed, and the SLO scan of the second area is executed. Similarly, after imaging of the mth area, a fixation light beam corresponding to the (m + 1) th fixation position is projected, rough alignment, fine alignment, focusing, etc. are executed, and SLO scan of the (m + 1) th area is executed. . This series of processing is repeated until the SLO scan of a plurality of areas is completed. The SLO scan of each area is, for example, a raster scan. The data processing unit 230 combines a plurality of SLO images corresponding to a plurality of areas to form a single SLO image representing a range including the plurality of areas.

  The SLO scan can be performed while changing the fixation position, or while performing rough alignment, alignment fine adjustment, focusing, or the like. For example, it is possible to execute fixation position change, coarse alignment, fine alignment adjustment, focusing, and the like while repeatedly executing SLO scan (raster scan or the like). It is also possible to perform SLO scan while continuously moving the fixation position.

<Action and effect>
Operations and effects of the ophthalmologic photographing apparatus according to the embodiment and the modification will be described.

  The ophthalmologic photographing apparatus according to the embodiment includes an image acquisition unit, a fixation optical system, an optical system moving unit, a first position detecting unit, and a control unit.

  The image acquisition unit includes an optical system that projects light onto the eye to be examined and detects the return light, and obtains an image of the eye to be examined from the detection result obtained by the optical system. In the above embodiment, this optical system includes elements included in the OCT unit 100 and elements that form a measurement optical path in the fundus camera unit 2. The image acquisition unit includes an image forming unit 200 in addition to the optical system. The image acquisition unit is configured to be able to execute at least one of OCT and SLO, for example.

  The fixation optical system projects a fixation light beam according to a preset fixation position onto the eye to be examined. In the above embodiment, the fixation optical system includes the LCD 39 and an element that guides the light beam output from the LCD 39 to the eye to be examined.

  The optical system moving unit includes a configuration for moving the optical system in the image acquisition unit, and the optical system moving unit 150 in the above embodiment corresponds to this.

  The first position detection unit detects the position of the eye to be examined. In the above embodiment, the pair of anterior eye cameras 5A and 5B and the first alignment processing unit 231 correspond to the first position detection unit. Moreover, in the said modification, the combination of the front image acquisition part for imaging | photographing a to-be-tested eye from the front, and the 1st alignment process part 231 corresponds to a 1st position detection part. Alternatively, a combination of an index optical system that projects an index beam onto the cornea of the eye to be examined and detects a reflected beam from the cornea and the first alignment processing unit 231 corresponds to the first position detection unit.

  After the fixation optical system projects a fixation light beam corresponding to a new fixation position onto the eye to be examined, the first position detection unit detects the position of the eye to be examined. That is, the first position detection unit detects the position of the eye to be examined after the fixation position is changed. The control unit controls the optical system moving unit based on the position of the subject eye detected after the fixation position is changed. In the above embodiment, the main control unit 211 corresponds to the control unit.

  According to the ophthalmologic photographing apparatus configured as described above, the position of the eye to be examined after changing the fixation position can be actually detected, and the alignment of the optical system can be performed according to the detection result. Therefore, it is possible to accurately adjust the shooting conditions accompanying the change in the fixation position.

  In the embodiment having the OCT function, the optical path length can be adjusted after the alignment. For this purpose, the optical system includes an interference optical system and an optical scanner for performing OCT. The interference optical system projects measurement light onto the eye to be examined, generates interference light by superimposing the return light and the reference light, and detects the interference light. In the above embodiment, the elements that form the measurement optical path, the reference optical path, and the optical path of the interference light correspond to the interference optical system. The optical scanner is disposed in the optical path of the measurement light, and the optical scanner 42 in the above embodiment corresponds to this.

  Furthermore, the image acquisition unit includes a cross-sectional image forming unit that forms a cross-sectional image based on data collected by the interference optical system and the optical scanner. The image forming unit 220 (and the data processing unit 230) in the above embodiment corresponds to the cross-sectional image forming unit. In addition, an optical path length changing unit that changes the optical path length of at least one of the measurement light and the reference light is provided. In the above embodiment, the optical path length changing unit 41 or the combination of the corner cube 114 and the reference driving unit 114A corresponds to the optical path length changing unit. The control unit can execute control (optical path length adjustment) of the optical path length changing unit in addition to control (alignment) of the optical system moving unit.

  The optical path length adjustment is performed by, for example, auto Z. Therefore, after control (alignment) of the optical system moving unit, data is collected by the interference optical system and the optical scanner (that is, OCT scan is executed). The cross-sectional image forming unit forms a cross-sectional image based on the collected data. Further, the first analysis unit analyzes the cross-sectional image to obtain the displacement of the eye to be examined with respect to a predetermined position in the optical axis direction of the optical path of the measurement light. In the above embodiment, the optical path length adjustment processing unit 234 corresponds to the first analysis unit. The control unit executes control (optical path length adjustment) of the optical path length changing unit so as to cancel the displacement obtained by the first analysis unit.

  According to such a configuration, in addition to the alignment accompanying the change of the fixation position, the optical path length adjustment of the interference optical system for OCT can be automatically executed, so that photographing with the change of the fixation position is easy. And it becomes possible to carry out smoothly.

  In an embodiment having an OCT function, polarization adjustment can be performed after the alignment. For this purpose, a polarization state changing unit is provided for changing the polarization state of at least one of the measurement light and the reference light. The polarization controller 118 in the above embodiment corresponds to a polarization adjustment processing unit. The control unit can execute control of the optical path length changing unit in addition to control of the optical system moving unit.

  According to such a configuration, in addition to the alignment associated with the change of the fixation position, the polarization adjustment for OCT can be automatically executed, so that the imaging with the change of the fixation position can be performed easily and smoothly. Is possible.

  In an embodiment having an OCT function or an SLO function, focusing can be performed after the alignment. For this purpose, the optical system includes a focusing lens for changing the focal position. In the above embodiment, the OCT focusing lens 43 (and the imaging focusing lens 31) corresponds to the focusing lens. Further, a focusing lens moving unit for moving the focusing lens is provided. In the above-described embodiment, the OCT focusing driving unit 43A (and the imaging focusing driving unit 31A) corresponds to the focusing lens moving unit. The control unit executes control (focusing) of the focusing lens moving unit in addition to control (alignment) of the optical system moving unit.

  According to such a configuration, since focusing can be automatically executed in addition to the alignment associated with the change in the fixation position, it is possible to easily and smoothly perform photographing with the change in the fixation position.

  The first position detection unit has an arbitrary configuration. For example, the first position detection unit may include two or more imaging units and a second analysis unit. The two or more photographing units photograph the subject's eye from different directions, and the pair of anterior eye cameras 5A and 5B in the above embodiment correspond to this. The second analysis unit is configured to obtain the position of the eye to be examined by analyzing two or more images acquired substantially simultaneously by two or more imaging units, and the first alignment processing unit 231 in the above-described embodiment is configured to obtain the position of the eye. It corresponds to. The control unit controls the optical system moving unit based on the position of the eye to be examined obtained by the second analysis unit so that the optical system and the eye to be examined have a predetermined positional relationship (that is, performs alignment).

  Another example of the first position detection unit includes a front image acquisition unit and a third analysis unit. The front image acquisition unit images the eye to be examined from the front. In the above embodiment, the illumination optical system 10 and the photographing optical system 30 correspond to the front image acquisition unit. The third analysis unit obtains the position of the eye to be examined by analyzing the front image acquired by the front image acquisition unit. In the above embodiment, the first alignment processing unit 231 corresponds to the third analysis unit. The control unit controls the optical system moving unit based on the position of the eye to be examined obtained by the third analyzing unit (that is, performs alignment) so that the optical system and the eye to be examined have a predetermined positional relationship.

  Still another example of the first position detection unit includes an index optical system and a fourth analysis unit. The index optical system projects an index light beam onto the cornea of the eye to be examined and detects a reflected light beam from the cornea. The indicator light beam forms, for example, a bright spot image or a ring image on the cornea. The fourth analysis unit obtains the position of the eye to be examined by analyzing the detection result obtained by the index optical system. In the above embodiment, the first alignment processing unit 231 corresponds to the fourth analysis unit. The control unit controls the optical system moving unit based on the position of the eye to be examined obtained by the fourth analysis unit (that is, performs alignment) so that the optical system and the eye to be examined have a predetermined positional relationship.

  The alignment state achieved by the above alignment (coarse alignment) can be finely adjusted. For this purpose, a second position detection unit capable of detecting the position of the eye to be examined with an accuracy equal to or higher than the detection accuracy of the first position detection unit is provided. The second position detection unit may be configured to include elements different from the first position detection unit, or may be configured from the same elements as the first position detection unit. In the above embodiment, the combination of the pair of anterior eye cameras 5A and 5B (or the alignment optical system 50) and the second alignment processing unit 232 corresponds to the second position detection unit. After the optical system moving unit is controlled based on the position of the eye to be examined detected by the first position detecting unit, the second position detecting unit detects the position of the eye to be examined. That is, the position of the eye to be examined after the rough alignment is performed is detected by the second position detection unit. The control unit controls the optical system moving unit based on the position of the eye to be examined detected by the second position detection unit (that is, performs fine alignment adjustment).

  According to such a configuration, since the alignment state can be finely adjusted after the rough alignment accompanying the change of the fixation position, it is possible to easily and smoothly perform the photographing with the change of the fixation position.

  The configuration and operation of the elements included in the ophthalmologic photographing apparatus according to the embodiment are not limited to the items exemplified above.

  The embodiment described above is merely an example of the present invention. A person who intends to implement the present invention can arbitrarily make modifications (omission, substitution, addition, etc.) within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Ophthalmology imaging device 2 Fundus camera unit 5A, 5B Anterior eye part camera 10 Illumination optical system 30 Imaging optical system 39 LCD
100 OCT unit 150 Optical system moving unit 211 Main control unit 220 Image forming unit 231 First alignment processing unit

Claims (10)

Including an optical system for projecting light onto the eye to be examined and detecting the return light, and an image acquisition unit for obtaining an image of the eye to be examined from a detection result obtained by the optical system;
A fixation optical system that projects a fixation light beam corresponding to a preset fixation position onto the eye to be examined; and
An optical system moving unit for moving the optical system;
A first position detector for detecting the position of the eye to be examined;
A control unit and
After the fixation optical system projects a fixation light beam corresponding to a new fixation position onto the eye to be examined, the first position detection unit detects the position of the eye to be examined,
The said control part controls the said optical system moving part based on the said position. The ophthalmic imaging device characterized by the above-mentioned. The optical system is
An interference optical system that projects measurement light onto the eye to be examined, generates interference light by superimposing the return light and reference light, and detects the interference light;
An optical scanner disposed in the optical path of the measurement light,
The ophthalmic imaging apparatus according to claim 1, wherein the image acquisition unit includes a cross-sectional image forming unit that forms a cross-sectional image based on data collected by the interference optical system and the optical scanner. An optical path length changing unit that changes an optical path length of at least one of the measurement light and the reference light;
The ophthalmologic photographing apparatus according to claim 2, wherein the control unit executes control of the optical path length changing unit in addition to control of the optical system moving unit. After the control of the optical system moving unit, the interference optical system and the optical scanner collect data,
The cross-sectional image forming unit forms a cross-sectional image based on the data,
A first analysis unit that obtains a displacement of the eye to be examined with respect to a predetermined position in the optical axis direction of the optical path of the measurement light by analyzing the cross-sectional image;
The ophthalmic imaging apparatus according to claim 3, wherein the control unit executes control of the optical path length changing unit so as to cancel the displacement. A polarization state changing unit for changing the polarization state of at least one of the measurement light and the reference light;
The ophthalmic imaging apparatus according to claim 2, wherein the control unit executes control of the optical path length changing unit in addition to control of the optical system moving unit. The optical system includes a focusing lens for changing a focal position,
A focusing lens moving unit for moving the focusing lens;
The ophthalmic imaging apparatus according to claim 1, wherein the control unit executes control of the focusing lens moving unit in addition to control of the optical system moving unit. The first position detector is
Two or more imaging units for imaging the eye to be examined from different directions;
A second analysis unit for determining the position of the eye to be examined by analyzing two or more images acquired substantially simultaneously by the two or more imaging units;
The control unit controls the optical system moving unit based on the position obtained by the second analysis unit so that the optical system and the eye to be examined have a predetermined positional relationship. Item 7. The ophthalmologic photographing apparatus according to any one of Items 1 to 6. The first position detector is
A front image acquisition unit for photographing the eye to be examined from the front;
A third analysis unit for determining the position of the eye to be examined by analyzing the front image acquired by the front image acquisition unit;
The control unit controls the optical system moving unit based on the position obtained by the third analysis unit so that the optical system and the eye to be examined have a predetermined positional relationship. Item 7. The ophthalmologic photographing apparatus according to any one of Items 1 to 6. The first position detector is
An index optical system for projecting an index beam onto the cornea of the eye to be examined and detecting a reflected beam from the cornea;
Analyzing a detection result obtained by the index optical system to obtain a position of the eye to be examined; and a fourth analysis unit,
The control unit controls the optical system moving unit based on the position obtained by the fourth analysis unit so that the optical system and the eye to be examined have a predetermined positional relationship. Item 7. The ophthalmologic photographing apparatus according to any one of Items 1 to 6. A second position detection unit capable of detecting the position of the eye to be examined with an accuracy equal to or higher than the detection accuracy of the first position detection unit;
After the optical system moving unit is controlled based on the position detected by the first position detecting unit, the second position detecting unit detects the position of the eye to be examined,
The ophthalmologic photographing apparatus according to claim 1, wherein the control unit controls the optical system moving unit based on the position detected by the second position detection unit.