JP2016158721A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus capable of easily performing smooth examination on a fixated eye.SOLUTION: An imaging apparatus includes fixation targets (fixation lights 71a-71i) to be presented to a subject eye E and a fixation optical system 70 capable of switching a position of fixation target presentation to change the sight line direction of the subject eye E. The imaging apparatus also includes a control unit 90 to detect sight line direction information, or the information of the sight line direction of the subject eye E. When the fixation target presentation position was switched from a first presentation position to a second presentation position, the control unit 90 of the imaging apparatus determines whether or not the sight line direction of the subject eye has changed with the switching of the fixation target presentation position, on the basis of change of the sight line direction information before and after the switching of the presentation position.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an ophthalmologic apparatus capable of switching a fixation lamp presenting position to a plurality of positions.

  Conventionally, in an ophthalmologic apparatus, by presenting a fixation target to an eye to be examined, the eye to be examined is observed, photographed, or examined (hereinafter collectively referred to as “optometry”). ) Is known. Such a device may be provided with a mechanism for changing the position of the eye to be examined by switching the presenting position of the fixation lamp to a plurality of presenting positions.

  For example, Patent Document 1 has a plurality of fixation lamps arranged at different positions on a plane that intersects the optical axis, and switches the fixation lamps to be lit while switching endothelial cell images at a plurality of locations on the cornea. A device for taking pictures is described.

JP 2011-245184 A

  However, when performing an optometry while switching the fixation target presentation position, the subject may not be able to fixate the fixation target properly, and the optometry may be performed with poor fixation. In this case, there is a high possibility that an optometry result for a desired position cannot be obtained.

  The present disclosure has been made in view of the problems of the prior art, and an object thereof is to provide an ophthalmologic apparatus that can easily perform optometry in a state in which fixation is performed.

  An ophthalmologic apparatus according to a first aspect of the present disclosure has a fixation target presented to an eye to be examined, and a fixation optical system capable of switching a presentation position of the fixation target in order to change a gaze direction of the subject eye Gaze direction information detecting means for detecting gaze direction information, which is information relating to the gaze direction of the eye to be examined, and a second presentation position in which the presentation position of the fixation target is different from the first presentation position from the first presentation position Whether or not the gaze direction of the eye to be examined has changed with the switching of the fixation target presentation position, the gaze direction information before and after the fixation target presentation position is switched. Determining means for determining based on the change.

  According to the present disclosure, it is easy to smoothly perform optometry in a state where fixation is performed.

It is the figure which showed the external appearance when the imaging device 100 which concerns on this embodiment is seen from the side. 1 is a schematic configuration diagram illustrating an example of an optical arrangement when an optical system housed in a housing 1a of an imaging device 100 is viewed from above. It is a figure when the 1st projection optical system 60 and the 2nd projection optical system 65 are seen from the subject side. It is a figure which shows an example of the anterior ocular segment observation screen at the time of image | photographing the endothelium of a cornea center part, (a) is a display example in case there exists a misalignment, (b) is a display example in the state with alignment appropriate It is. 3 is a flowchart illustrating a shooting operation in the shooting apparatus 100. It is a figure shown about the epithelial peak detected on the detector 89. FIG. 5 is a schematic diagram showing an example of an endothelium observation screen 300. FIG. (A) shows an anterior ocular segment image when the line of sight of the eye E faces a fixation lamp arranged in the vicinity of the fixation optical axis L4, and (b) shows the line of sight of the eye to be examined with respect to (a). It is the figure which showed the anterior eye part image when a direction turns to a paper surface lower left direction. FIGS. 8A and 8B are anterior ocular segment images similar to FIGS. 8A and 8B, respectively, and are diagrams for explaining an example of a method for deriving gaze direction information using the anterior segment image. FIGS. It is.

  Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, an ophthalmologic imaging apparatus 100 (hereinafter simply referred to as “imaging apparatus 100”) will be described as an example of an ophthalmic apparatus according to the present disclosure.

  First, an external configuration of the ophthalmologic apparatus 100 will be described with reference to FIG. In the following description, the X direction in FIG. 1 is described as the left-right direction, the Y direction is the up-down direction, and the Z direction is the front-back direction.

  The imaging apparatus 100 is an apparatus that captures an image of a corneal region of the eye E. As illustrated in FIG. 1, the photographing apparatus 100 includes a photographing unit 1 (apparatus main body), a base 2, a face support unit 3, and a movable base 4. The imaging device 100 is a so-called stationary device. The optical system of the photographing apparatus 100 is accommodated in the housing 1 a of the photographing unit 1.

  The movable table 4 can be moved on the base 2 by a sliding mechanism (not shown). The moving table 4 is provided with an XYZ driving unit 5. The imaging unit 1 can move in the left-right direction (X direction), the up-down direction (Y direction), and the front-rear direction (Z direction) with respect to the eye E by the XYZ driving unit 5. The movable table 4 moves on the base 2 in the XZ direction when the examiner operates the joystick 6 while tilting it. Further, when the examiner rotates the rotary knob 6 a, the photographing unit 1 is moved in the Y direction by the Y drive of the XYZ drive unit 5. A start switch 56 is provided on the top of the joystick 6. The monitor 97 is provided on the examiner side of the housing 1 a of the imaging unit 1.

  In addition, as a structure which moves the imaging | photography part 1, the structure which moves the imaging | photography part 1 with respect to a right-and-left eye by the drive of the motor of the drive part 5 without providing a mechanical sliding mechanism may be sufficient. Moreover, the structure which has a touch panel as a manual operation member like the joystick 6 may be sufficient as this apparatus.

  In the present embodiment, the monitor 97 is provided on the surface of the housing 1a opposite to the subject side surface. However, the monitor 97 may be disposed at another position of the housing 1a, or may be provided separately from the photographing apparatus 100.

  Next, an optical system and a control system of the photographing apparatus 100 will be described with reference to FIG. The optical arrangement shown in FIG. 2 is an arrangement when the optical system housed in the photographing unit 1 is viewed from above.

  The imaging apparatus 100 of the present embodiment includes a cornea imaging optical system 10 (“second optical system” in the present embodiment), a front projection optical system 50, first projection optical systems 60a and 60b, and a second projection optical system 65 (65a). -65d) (see FIG. 3), internal fixation optical system 70 (70a-70g), external fixation optical system 75 (75a-75f) (see FIG. 3), and anterior eye observation optical system 80 (this embodiment) The “observation optical system” and the Z alignment detection optical system 85 are included.

  The cornea photographing optical system 10 includes an illumination optical system 10a (“second light projecting optical system” in the present embodiment) and a light receiving optical system 10b (“second light receiving optical system” in the present embodiment). The cornea photographing optical system 10 projects light from the illumination light source 11 (first light source) toward the cornea Ec of the eye E by the illumination optical system 10a. In addition, the cornea photographing optical system 10 receives the reflected light emitted from the illumination light source 11 and reflected by the cornea Ec by the light receiving optical system 10b by the imaging element 22 (“second photodetector” in the present embodiment). The imaging apparatus 100 images the corneal region of the eye in a non-contact manner using the cornea imaging optical system 10.

  The optical axes of the illumination optical system 10a and the light receiving optical system 10b intersect, for example, on the eye E. The illumination optical system 10a and the light receiving optical system 10b are advantageously arranged symmetrically with respect to a certain central axis. In the present embodiment, the optical axis L2 of the illumination optical system 10a and the optical axis L3 of the light receiving optical system 10b are symmetrical with respect to the optical axis L1.

  The illumination optical system 10 a of this embodiment includes an illumination light source 11, a condenser lens 12, a slit plate 13, a dichroic mirror 14, and a light projecting lens 15. The illumination light source 11 emits illumination light used for photographing a corneal region. In the present embodiment, the illumination light source 11 emits visible light. As the illumination light source 11, for example, a visible LED, a flash lamp, or the like may be used. The dichroic mirror 14 reflects visible light and transmits infrared light. The slit plate 13 and the cornea Ec are disposed at a substantially conjugate position with respect to the objective lens 15. The light emitted from the illumination light source 11 is collected by the condenser lens 12 and passes through the slit formed in the slit plate 13. The slit light that has passed through the slit plate 13 is reflected by the dichroic mirror 14, and then converged by the light projecting lens 15, thereby irradiating the cornea Ec.

  The light receiving optical system 10b receives reflected light from the cornea Ec including endothelial cells by the imaging element 22. The light receiving optical system 10b of this embodiment includes an objective lens 16, a dichroic mirror 17, a mask 18, a first imaging lens 19, a mirror 20, a second imaging lens 21, a two-dimensional imaging device 22 (hereinafter referred to as “imaging device 22”). ”). The dichroic mirror 17 reflects visible light and transmits infrared light. The mask 18 is disposed at a position substantially conjugate with the cornea Ec. The first imaging lens 19 and the second imaging lens 21 form an imaging optical system that forms an endothelial cell image on the image sensor 22. The imaging element 22 is used for photographing endothelial cells. The image sensor 22 is disposed at a position substantially conjugate with the cornea Ec. As the image sensor 22, for example, a two-dimensional CCD image sensor (Charge coupled device image sensor), a two-dimensional CMOS (Complementary Metal Oxide Semiconductor Image Sensor), or the like may be used.

  The light guided from the illumination optical system 10a to the cornea Ec is reflected in the cornea Ec and thereby guided in the optical axis L3 direction (oblique direction). Thereafter, the light is once imaged by the mask 18 through the objective lens 16 and the dichroic mirror 17. The mask 18 blocks light that becomes noise when an endothelial cell image is acquired. The light that has passed through the mask 18 forms an image on the image sensor 22 through the first imaging lens 19, the mirror 20, and the second imaging lens 21. As a result, a high-magnification endothelial cell image is acquired.

  The front projection optical system 50 projects an alignment index for XY alignment from the front toward the cornea Ec. The front projection optical system 50 includes an infrared light source 51, a light projecting lens 52, and a half mirror 53. The front projection optical system 50 projects infrared light for XY alignment detection onto the cornea Ec from the direction of the optical axis L1 when the infrared light source 51 is turned on.

  The first projection optical systems 60a and 60b and the second projection optical systems 65a to 65d project alignment indexes for XYZ alignment. In the photographing apparatus 100, rough alignment is performed by using alignment indexes projected from the first projection optical system 60 and the second photographing optical system 65.

  The first projection optical systems 60a and 60b project an alignment index at infinity toward the cornea Ec from an oblique direction. The first projection optical systems 60a and 60b are disposed so as to be inclined at a predetermined angle with respect to the optical axis L1. The first projection optical systems 60a and 60b have infrared light sources 61a and 61b and collimator lenses 63a and 63b, respectively, are arranged symmetrically with respect to the optical axis L1, and are infinite with respect to the eye E. An index is projected (see FIG. 3). The first projection optical systems 60a and 60b are disposed on substantially the same meridian as the horizontal direction passing through the optical axis L1 (see FIG. 3).

  The lights emitted from the light sources 61a and 61b are collimated by the collimator lenses 63a and 63b, respectively, and then projected onto the cornea Ec. As a result, indices i20 and i30 are formed on the cornea Ec (see FIG. 4).

  The second projection optical systems 65a to 65d project alignment indexes at a finite distance toward the cornea Ec from a plurality of oblique directions. The second projection optical systems 65a to 65d are arranged to be inclined with respect to the optical axis L1. The second projection optical systems 65a to 65d have infrared light sources 66a to 66d, are arranged symmetrically with respect to the optical axis L1, and project a finite index onto the eye E. The second projection optical systems 65a and 65b are disposed above the optical axis L1 and are disposed at the same height with respect to the Y direction. The second projection optical systems 65c and 65d are disposed below the optical axis L1 and are disposed at the same height with respect to the Y direction. The second projection optical systems 65a and 65b and the second projection optical systems 65c and 65d are arranged in a vertically symmetrical relationship with the optical axis L1 in between.

  Here, the light from the light sources 66a and 66b is irradiated obliquely upward toward the upper part of the cornea Ec, and indexes i40 and i50 which are virtual images of the light sources 66a and 66b are formed. In addition, light from the light sources 66c and 66d is irradiated obliquely downward toward the lower portion of the cornea Ec, and indexes i60 and i70 that are virtual images of the light sources 66c and 66d are formed (see FIG. 4).

  According to the index projection optical system as described above, the index i10 is formed at the corneal apex of the eye E (see FIG. 4). In addition, the indices i20 and i30 by the first projection optical systems 60a and 60b are formed symmetrically with respect to the index i10 at the same horizontal position as the index i10. Furthermore, the indices i40 and i50 by the second projection optical systems 65a and 65b are formed symmetrically with respect to the index i10 above the index i10. The indices i60 and i70 by the second projection optical systems 65c and 65d are formed symmetrically with respect to the index i10 below the index i10.

  The photographing apparatus 100 includes a fixation optical system (for example, the internal fixation optical system 70 and the external fixation optical system 75 in FIG. 2). In the present embodiment, each of the fixation optical systems 70 and 75 has a plurality of fixation lamps arranged on a surface orthogonal to the optical axis, and changes the line-of-sight direction of the eye to be examined by switching the lighting position. .

  The internal fixation optical system 70 (70a to 70i) projects a fixation target onto the eye E from the inside of the housing 1a. Each of the internal fixation optical systems 70 a to 70 i includes one of visible light sources (fixation lamps) 71 a to 71 i, a light projecting lens 72, and a dichroic mirror 73. The visible light sources (fixation lamps) 71a to 71i are arranged at different positions with respect to the direction orthogonal to the optical axis L4. The dichroic mirror 73 reflects visible light and transmits infrared light. Visible light emitted from the light source 71 is converted into a parallel light beam by the light projection lens 72 and then reflected by the dichroic mirror 73. As a result, the fixation target is projected onto the fundus of the eye E. For example, the visible light source 71a is disposed in the vicinity of the optical axis L4. The visible light source 71a is used to guide the eye E in the front direction. The visible light source 71 is turned on when an endothelial image of the central part of the cornea Ec is obtained. Further, the plurality of visible light sources 71b to 71i are arranged on the same circumference with the optical axis L4 as the center. In the example of FIG. 2, 45 degrees are arranged at each position of 0 degree, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, and 315 degrees as viewed from the subject. The visible light sources 71b to 71i are used to obtain an endothelium image in the vicinity of the central portion of the cornea by guiding the visual line direction of the eye E to the peripheral direction.

  The external fixation optical systems 75a to 75f project a fixation target onto the eye E from the outside of the housing 1a. The external fixation optical systems 75 a to 75 f have a plurality of fixation targets arranged at different positions with respect to the XY directions, and cause the fixation direction of the eye to be examined to be swung more than the internal fixation optical system 70. The external fixation optical systems 75a to 75f are provided outside the housing 1a (that is, outside the imaging unit 1) and on the eye side to be examined. For example, it may be provided on the eye side housing surface of the housing 1a. The external fixation optical systems 75a to 75f shown in FIG. 3 have visible light sources (fixation lamps) 76a to 76f, and are 2 o'clock when viewed from the subject on the same circumference centered on the optical axis L1. They are arranged at the 4 o'clock, 6 o'clock, 8 o'clock, 10 and 12 o'clock positions. The visible light sources 76a to 76f are used to obtain an endothelial image in the peripheral part of the cornea by guiding the visual line direction of the eye E to the peripheral direction. In this case, an outer endothelial cell image is acquired further than the images acquired by the visible light sources 71b to 71g.

  For example, when photographing the lower cornea, the position of the fixation lamp (fixation target) is set upward, and fixation of the eye E is guided upward. When photographing the upper cornea, the position of the fixation lamp (fixation target) is set downward, and fixation of the eye E is guided downward.

  Further, in the present embodiment, a case where an optical system that changes a line-of-sight direction that is guided by switching and lighting a plurality of fixation lamps at different positions is described, but the present invention is not necessarily limited thereto. A single fixation lamp may be configured to move in a direction orthogonal to the optical axis, and the line-of-sight direction of the eye E may be changed. As another configuration, the fixation optical system may have a display panel such as a liquid crystal display or an organic EL (electroluminescence), and change the line-of-sight direction of the eye E by controlling the light emission position. .

  The anterior segment observation optical system 80 is used for observing and photographing the anterior segment image from the front. The anterior ocular segment observation optical system 80 includes an objective lens 81 and a two-dimensional image sensor 82 (“photodetector” in the present embodiment, hereinafter abbreviated as “image sensor 82”). The image sensor 82 captures the anterior segment image and the alignment index. The alignment in the XY direction and the rough alignment in the Z direction are performed based on an alignment index image photographed by the image sensor 82. As the imaging element 82, for example, a two-dimensional CCD image sensor, a two-dimensional CMOS, or the like may be used. As a light source used for photographing the anterior segment, an anterior segment illumination light source (not shown) is used.

  The output of the image sensor 82 is input to the control unit 90 described later. As shown in FIG. 4, the anterior segment image captured by the image sensor 82 is displayed on the monitor 97. Note that the reticle LT electronically displayed on the monitor 97 indicates a reference for XY alignment. The anterior ocular segment observation optical system 80 also serves as a detection optical system for detecting the alignment state of the imaging unit 1 with respect to the eye E.

  In the present embodiment, the Z alignment detection optical system 85 is used for precise alignment in the Z direction. The Z alignment detection optical system 85 includes a light projection optical system 85a and a detection optical system 85b. In the present embodiment, the optical axis L2 of the light projecting optical system 85a and the optical axis L3 of the detection optical system 85b are arranged at symmetrical positions with respect to the optical axis L1. The Z alignment detection optical system 85 projects light (that is, detection light) for detecting the focus state of the cornea photographing optical system 10 with respect to the eye cornea Ec to be examined toward the eye cornea Ec from an oblique direction. On the other hand, the detection optical system 85b includes a detector 89 (photodetector) in which a plurality of pixels are arranged, and the detector 89 receives reflected light from the cornea Ec of light projected from the light projecting optical system 85a. To do.

  The light projecting optical system 85 a of this embodiment includes an illumination light source 86, a condenser lens 87, a pinhole plate 88, and a lens 15. The pinhole plate 88 is disposed at a position substantially conjugate with the cornea Ec. The detection optical system 85b of the present embodiment includes a lens 16 and a detector 89. As the detector 89, for example, a one-dimensional light receiving element (line sensor) may be used. The detector 89 and the cornea Ec are disposed at a substantially conjugate position. The infrared light emitted from the light source 86 illuminates the pinhole plate 88 through the condenser lens 87. The light that has passed through the opening of the pinhole plate 88 is projected onto the cornea Ec through the lens 20. Light is reflected by the cornea Ec toward the optical axis L3. Thereafter, the corneal reflection light is received by the detector 89 via the lens 16 and the dichroic mirror 17. The detector 89 outputs the intensity distribution in the depth direction of the corneal reflected light as a signal to the control unit 90. The output signal from the detector 89 is used to detect the alignment state in the Z direction. Here, the light receiving position of the detection light on the detector 89 is changed according to the positional relationship between the imaging unit 1 and the eye E in the Z direction. The imaging apparatus 100 detects the amount of misalignment in the Z direction by detecting the misalignment between the detection light receiving position and the proper alignment position.

  Next, a schematic configuration of the control system of the photographing apparatus 100 will be described.

  In the photographing apparatus 100, each unit is controlled by the control unit 90. The control unit 90 is connected to the drive unit 5, joystick 6, various light sources 11, 71, 61, 86, image sensors 22, 82, detector 89, HDD 94, image processing IC 95, operation input unit 96, and monitor 97. . The monitor 97 may be a touch panel. In this case, the monitor 97 also serves as a part of the operation input unit 96.

  The control unit 90 includes a CPU 91, a ROM 92, and a RAM 93. The CPU 91 is a processing device for executing various processes related to the photographing apparatus 100. The ROM 92 is a nonvolatile storage device that stores various control programs and fixed data. The RAM 93 is used as a rewritable volatile storage device, but is not limited to this. The RAM 93 stores temporary data when the control program is executed.

  The HDD 94 is used as a rewritable nonvolatile storage device, but is not limited to this. In the present embodiment, the HDD 94 stores a program for main processing described later. In addition, the image of the eye to be examined photographed by the photographing apparatus 100 is stored in the HDD 94.

  The image processing IC 95 is used as an image forming unit. The image processing IC 95 forms an image of an endothelial cell image (hereinafter referred to as “endothelial image”) by processing a signal output from the image sensor 22. Further, by processing the signal output from the image sensor 82, an image of the front image of the anterior segment (hereinafter referred to as “anterior segment image”) is formed. In the present embodiment, the image processing IC 95, which is a separate circuit from the control unit 90, performs image processing such as forming an image related to the eye to be examined. The configuration may be such that all or all of them are performed by the control unit 90.

  Next, with reference to the flowchart in FIG. 5, a photographing operation of a corneal endothelial cell image in the photographing apparatus 100 will be described. In order to obtain a corneal endothelial cell image in a wide range of the cornea, the imaging device 100 captures the endothelial cell image a plurality of times while switching the position of the fixation target. Details of the operation will be described below.

  The imaging apparatus 100 first aligns the apparatus with respect to the eye to be inspected using the anterior segment image obtained through the anterior segment observation optical system 80.

  At the time of alignment, lighting of the fixation lamp is started (S1). First, among the plurality of fixation lamps 71a to 71i and 76a to 76f, the fixation lamp 71a in the vicinity of the optical axis L4 is turned on. That is, the fixation target is presented to the eye E at the presentation position near the optical axis L4. In this case, the examiner instructs the subject to fixate the fixation lamp 71a (that is, the fixation target).

  Further, the CPU 91 starts to turn on the anterior segment observation light source (not shown), and starts generation of an anterior segment observation image (live image) by the image processing IC 95 and output to the monitor 97 (S2). The anterior ocular segment observation screen 200 is formed and displayed for use in alignment of the imaging unit 1 with respect to the eye E. In the present embodiment, the anterior ocular segment observation images sequentially formed by the image processing IC 95 are sequentially displayed on the anterior ocular segment observation screen 200 (see FIG. 4) on the monitor 97.

  Next, alignment processing is performed (S3). The alignment of the imaging unit 1 with respect to the eye E is performed by the alignment process (S3). Here, an alignment operation by the alignment process of the present embodiment will be described. First, the CPU 91 turns on the alignment light source.

  In the present embodiment, the alignment in the X and Y directions is performed in two steps: a rough manual alignment based on the operation of the joystick 6 and an automatic alignment. During the manual alignment based on the operation of the joystick 6, the CPU 91 detects the index image indices i40, i50, i60, i70 projected by the second projection optical systems 65a to 65d. When the indices i40, i50, i60, i70 are detected, the CPU 91 detects the center position of the rectangle composed of the indices i40, i50, i60, i70 as a substantially corneal apex. Based on the deviation between the rectangular center position and the image center position (that is, the optical axis center position of the anterior ocular segment observation optical system), the misalignment direction / deviation amount in the XY directions are detected. The CPU 91 moves the photographing unit 1 in the XY directions so that the misalignment falls within the allowable range. As a result, when the index image i10 is detected from the anterior ocular segment observation image, the CPU 91 ends the alignment using the index images i40 to i70 and performs the alignment using the index i10. The CPU 91 moves the photographing unit 1 in the XY directions so that the deviation amount with respect to the index image i10 and the alignment reference position (for example, the image center) falls within the allowable range. As described above, alignment in the XY directions is performed.

  In the present embodiment, the alignment in the Z direction is performed in two stages: a first automatic alignment and a second automatic alignment. In the first automatic alignment, detection results of index images i20 and i30 at infinity and index images i60 and i70 at finite distance are used. When the index i10 is detected, index images i20 and i30 at infinity are also detected. The CPU 91 obtains the misalignment direction / deviation amount in the Z direction by comparing the interval between the index images i20 and i30 and the interval between the index images i60 and i70 at finite distance (first alignment detection). Further, the CPU 91 moves the photographing unit 1 in the Z direction so that the misalignment in the Z direction falls within the allowable range (first automatic alignment). Here, when the photographing unit 1 is displaced in the working distance direction, the distance between the infinity indices i20 and i30 hardly changes, whereas the image distance between the finite index images i60 and i70 changes. Using this, the misalignment in the Z direction is obtained (for details, refer to Japanese Patent Laid-Open No. 6-46999). Note that index images i40 and i50 may be used instead of the index images i60 and i70. Further, the alignment state in the Z direction may be detected based on the distance of the index (index height) from the optical axis L1.

  After the completion of the first automatic alignment, the second automatic alignment is performed. Z alignment detection optical systems 85a and 85b are used for the second automatic alignment. During the second automatic alignment, the CPU 91 turns on the light source 86 to continuously project the detection light from the light projecting optical system 85a onto the cornea Ec (the light source 86 may be turned on in advance).

  The cornea reflected light of the detection light is detected by the detector 89 of the detection optical system 85b. The CPU 91 controls the driving unit 5 based on the signal output from the detector 89 and moves the photographing unit 1 in the Z direction. For example, the CPU 91 detects the peak P corresponding to the reflected light from the corneal epithelium in the waveform indicating the intensity distribution of the corneal reflected light in the depth direction based on the intensity distribution indicated by the output signal from the detector 89 ( (See FIG. 6). The drive unit 5 is driven so that the position Pz of the epithelial peak on the detector 89 is the position of a predetermined pixel of the detector 89 (for example, the position of the center pixel). As a result, in the imaging apparatus 100, the focus of the cornea imaging optical system 10 is set at or near the corneal epithelium. As described above, alignment in the Z direction is performed.

  In the present embodiment, the CPU 91 detects completion of alignment in the XYZ directions. For example, regarding the alignment in the XY directions, the CPU 91 detects the completion of alignment when it is determined that the amount of deviation from the index image i10 and the alignment reference position (for example, the image center) falls within an allowable range. For example, regarding the alignment in the Z direction, the CPU 91 detects the completion of alignment when it is determined that the position Pz of the epithelial peak is the position of a predetermined pixel of the detector 89. When the completion of the alignment state in the XYZ directions is detected, the CPU 91 ends the alignment process (S4). At this time, the CPU 91 turns off the alignment light source.

  After the completion of the alignment is detected by the CPU 91, in the present embodiment, a still image of the anterior ocular segment observation image obtained through the anterior ocular segment observation optical system 80 is acquired (captured) and stored in the HDD 94 (S4). .

  Further, after the alignment is completed, the CPU 91 starts acquisition of an observation image of the cornea (a live image in the present embodiment) using the cornea photographing optical system 10 and display on the monitor 97 (S5). In this case, for example, an observation screen 300 is displayed on the monitor 97 as shown in FIG. The live image of the cornea image is shown in the window 301 in the cornea observation screen 300. A fixation position graphic 304 is displayed on the observation screen 300. The fixation position graphic 304 indicates the positions of the fixation lights 71a to 71i and 76a to 76f that are lit when viewed from the eye E. The fixation position graphic 304 allows the examiner to easily grasp the imaging position of the endothelial image around the cornea center. Note that, following the second automatic alignment, the CPU 91 performs control so that the detection light is continuously projected from the light projecting optical system 85a.

  Next, the CPU 91 captures a corneal endothelial image (S6). In the present embodiment, first, a corneal endothelium image is taken in a state where the fixation lamp 75a is turned on. The corneal endothelium image is taken after the focus of the corneal imaging optical system 10 is adjusted to the corneal endothelium. More specifically, the focus of the corneal imaging optical system 10 is automatically adjusted to the corneal endothelium by controlling the drive of the drive unit 5 based on the signal output from the detector 89. Then, the CPU 91 captures an endothelial image. The controller 90 causes the illumination light source 12 to emit light. Then, at least one endothelial image is acquired by the image sensor 22, and the acquired endothelial image is stored in the memory 92 (auto shot). When acquiring a plurality of endothelial images, the control unit 90 controls the drive of the drive unit 5 to move the imaging unit 1a in a predetermined direction. Then, a plurality of endothelial images may be acquired by the imaging element 22 by causing the illumination light source 11 to emit light continuously during movement of the imaging unit 1a. In this case, the control unit 90 may perform auto-alignment or auto-tracking (see, for example, JP 2013-212217 A).

  Next, the CPU 91 changes the fixation lamp to be turned on from among the fixation lamps 71a to 71i and 76a to 76f (S7). Thereby, in this embodiment, the presentation position of the fixation target presented to the eye to be examined is switched from the first presentation position to the second presentation position different from the first presentation position based on the lighting switching signal. . Note that the first presentation position is the fixation target presentation position in the previous imaging when the corneal endothelial cell image is captured twice in succession, and the second presentation position is the fixation target in the subsequent imaging. Is the presenting position. In the process of S7 in the present embodiment, the fixation lamp to be lit is switched according to a predetermined fixation lamp lighting sequence. Here, as an example of the lighting order, it is assumed that switching is performed in the order of 71a → 71b → 71c →... (Omitted) → 71i → 76a → 76b →. According to this lighting sequence, for example, after the fixation lamp 71a is turned on, the fixation lamp 71b is switched on. That is, the fixation target presentation position is switched from the presentation position near L4 to the presentation position around L4 on the right side of L4. Here, when a fixation target is presented at a certain presentation position, it is assumed that the fixation lamp corresponding to the presentation position is in a state where the lighting state is continuously maintained (so-called constant lighting). However, the present invention is not limited to this, and the fixation target may be presented by repeatedly turning on and off (that is, blinking) the fixation light.

  Note that the lighting order of each fixation lamp (that is, the fixation target presentation order) does not necessarily have to be uniquely determined. A plurality of patterns may be prepared. In this case, a configuration in which the examiner can select the lighting order according to the purpose of photographing is also possible. Further, a configuration in which the examiner can arbitrarily set the lighting order before or at the time of photographing may be employed.

  After the fixation lamp presentation position is changed, the CPU 91 obtains a still image of the anterior ocular segment observation image obtained via the anterior ocular segment observation optical system 80 as in S4 described above (more specifically, Capture and store in HDD 94) (S8).

  The CPU 91 then obtains the two images obtained before and after the fixation target presentation position is switched (that is, before and after the output of the lighting switching signal for switching the fixation lamp presentation position). Gaze direction information is detected from the eye image (S9). That is, the first gaze direction information is acquired from the anterior segment image (first observation image) obtained when the fixation target presentation position is the first presentation position, and the fixation target presentation position is Second line-of-sight direction information is acquired from the anterior segment image (second observation image) obtained in the case of the two presentation positions. Thus, in this embodiment, the line-of-sight direction information is detected from each anterior segment image. The gaze direction information is information related to the gaze direction of the eye to be examined. In the process of S9, when the line-of-sight direction of the eye E is different, different information is detected as the line-of-sight direction information. Various types of information can be used as the gaze direction information obtained from the anterior segment image. Here, as a specific example, the position of the pupil of the eye to be examined and the position of the corneal bright spot sp are used (see FIG. 8). The corneal bright spot sp is formed at or near the corneal apex, for example, when the anterior segment illumination (not shown) from the anterior segment observation optical system 50 is irradiated to the cornea Ec.

  FIG. 8A shows an anterior eye image when the line of sight of the eye E faces a fixation target (fixation lamp 71a) arranged in the vicinity of the optical axis L4, and FIG. FIG. 8B shows an anterior ocular segment image when facing the lower left of the front view with respect to FIG. As described above, the position where the corneal luminescent spot sp is generated according to the line-of-sight direction changes with respect to the pupil. Therefore, the position of the pupil of the eye E (for example, the position of the pupil center ic) and the position of the corneal luminescent spot sp From this, an approximate line-of-sight direction can be obtained. In such a specific example, the CPU 91 detects the center position of the pupil and the corneal bright spot position from each anterior eye image by performing image processing on each anterior eye image. Then, as the line-of-sight direction information detected from each anterior segment image, for example, position information of the corneal luminescent spot sp with respect to the position of the pupil center ic in each anterior segment image is acquired.

  Next, when the fixation target presentation position is switched, the CPU 91 determines whether or not the line-of-sight direction of the eye to be examined has changed with the switching of the fixation target presentation position (S10). This determination is performed based on the amount of change in the gaze direction information before and after the fixation target presentation position is switched (that is, the difference between the first gaze direction information and the second gaze direction information). When the amount of change in the line-of-sight direction information is small, it is considered that there is little possibility that the subject is properly fixed with respect to the fixation target after the presentation position is switched.

  More specifically, in the determination of S10, the CPU 91 compares the amount of change in the line-of-sight direction information with a certain threshold value, and outputs a determination result corresponding to the magnitude relationship between the change amount and the threshold value. Here, the amount of change in the line-of-sight direction information may be, for example, the amount of change in the position of the corneal bright spot sp on the basis of the pupil center ic in the first observation image and the second observation image.

  Further, the threshold is a change amount of the gaze direction information due to the fixation fine movement, and a large value is set with respect to the change amount assumed in the normal eye to be examined. In the specific example in which the amount of change in the position of the corneal luminescent spot sp is used as the amount of change in the line-of-sight direction information, the threshold value is set to a large value with respect to the amount of change in the position of the corneal luminescent spot sp associated with the fixation eye movement. The

  Here, the threshold value may be set to a large value with respect to a change in the viewing angle caused by flicking (microsaccade), which is the movement with the largest amplitude in the fixation fine movement. There are various theories about the size of the flick, but it is said that it is within 1 °. For this reason, for example, if the threshold is set to 1 ° or more, it is considered that a change in the line of sight due to fine fixation movement and a change in the line of sight direction other than the fixation fine movement can be distinguished well. The threshold value needs to be set to a small value with respect to the interval between the fixation target presentation positions. For example, when the interval between the fixation target presentation positions is about 5 ° at the narrowest portion, for example, a threshold value may be set between about 2 ° and 4 °.

  In the present embodiment, in the determination of S10, when the amount of change in the line-of-sight direction information between the first observation image and the second observation image is larger than the threshold value, it is determined that the line-of-sight direction of the eye to be examined has changed (S10). : Yes). On the other hand, when the amount of change in the line-of-sight direction information is smaller than the threshold value, it is determined that the line-of-sight direction of the eye to be examined has not changed (S10: No).

  In addition to the determination in S10, a change in the line-of-sight direction information between the first observation image and the second observation image (for example, the direction of the movement vector of the corneal bright spot sp with respect to the pupil center ic) The CPU 91 may further determine whether or not the change is in the direction corresponding to the change in the fixation target presentation position. For example, when the second presentation position is higher than the first presentation position, whether or not the change in the gaze direction information indicates an upward change in the gaze direction. The determination may be made based on the change (specifically, based on the sign of the movement vector of the corneal bright spot sp with the pupil center ic as a reference). If the gaze direction does not change in the direction corresponding to the change in the fixation target presentation position, the subject is not properly fixed to the fixation target after the presentation position is switched. Conceivable. Therefore, in this case, the CPU 91 may proceed to the same step as that in the case of No determination in the processing of S10. Further, if it is determined that the line-of-sight direction has changed in the direction corresponding to the change in the fixation target presentation position, the same step as in the case of Yes determination may be made in the processing of S10 described above.

  When it is determined that the line-of-sight direction of the eye to be examined is not changed by the process of S10 (S10: No), the CPU 91 causes the information providing unit to output information indicating that there is a possibility of fixation failure (S11). ). As an example, in the present embodiment, a monitor 97 is used as the information providing unit. For example, the CPU 91 notifies the examiner that there is a possibility of fixation failure by displaying a message such as “There is a possibility of fixation failure” on the monitor 97. As a result, the examiner who has confirmed the message can inquire whether or not the subject is fixation, or can instruct the subject to prompt fixation.

  After displaying the message, the CPU 91 returns to the process of S8 to newly acquire an anterior ocular segment image and detect gaze direction information (S8, S9). The CPU 91 newly sets the line-of-sight direction information as the second line-of-sight direction information, and based on the amount of change between the same first line-of-sight direction information and the new second line-of-sight direction information as before, the line of sight of the eye to be examined The direction change is again determined (S10). Therefore, the imaging operation is on standby until the subject's line-of-sight direction changes beyond the threshold (for example, imaging of a corneal endothelial cell image at a second presentation position as described later is on standby). Note that the standby for the photographing operation may be canceled in response to a predetermined input operation on the operation input unit 96.

  On the other hand, when it is determined that the line-of-sight direction of the eye E has changed by the process of S10 (S10: Yes), the CPU 91 executes the alignment of the imaging unit 1 with respect to the eye E again (S11), and then A corneal endothelium image is taken at the second presentation position (S12).

  Since the endothelial cell imaging at the first presentation position has been performed so far, the imaging unit 1 has been moved to the endothelial side. Also, in the eye E, the position that becomes the surface of the cornea changes due to the change of the line-of-sight direction. Therefore, the alignment is performed again so that the eye E and the corneal imaging optical system 10 have a predetermined positional relationship (for example, the positional relationship in which the focus of the corneal imaging optical system 10 is set at the corneal apex position). I do. The alignment here may be performed by all or part of the operations in the alignment process (S3) described above.

  Then, after completion of the alignment is detected by the CPU 91, an endothelial cell image is captured when the fixation target presentation position is the second presentation position (S12). A specific photographing operation is performed in the same manner as in S6. The CPU 91 stores the photographed endothelial cell image in the HDD 94.

  Next, the CPU 91 determines whether or not imaging of the endothelial cells is completed at each fixation target presentation position (S13). If there is a position for presenting a fixation target that has not been photographed, the process returns to S7, the lighting position of the fixation lamp is further switched, and the process is repeated. That is, the processes from S7 to S13 are newly executed. In this case, the presentation position of the fixation lamp (fixation target) that is turned on in the process of S7 that is newly executed (that is, this time) is set as the second presentation position. Further, the presenting position of the fixation lamp that has been turned on by the previous processing of S7 (one time before this time) is set as the first presenting position. Therefore, in the process of S10, by comparing the still image of the anterior segment image obtained at the present presentation position with the still image of the anterior segment image obtained at the previous presentation position, the line-of-sight direction of the eye to be examined is determined. It is determined whether it has changed.

  On the other hand, when the photographing at each fixation target presenting position is completed (S13: Yes), this process ends.

  Here, since there are individual differences in the shape and refraction of each part in the eye to be examined, it is difficult to easily and accurately detect the line-of-sight direction of the eye to be examined. For this reason, for example, it is not easy to measure the degree of coincidence of the gaze direction with the direction of the fixation target and grasp the fixation state of the eye to be inspected based on the measurement result.

  On the other hand, the ophthalmologic apparatus 100 according to this embodiment determines whether or not the gaze direction of the eye E has changed with the change of the fixation target presentation position before and after the fixation target presentation position is switched. Judgment is made based on a change in direction information. According to this, even if the fixation position interval of each fixation target is small, if the fixation of the eye to be examined is switched, the gaze direction information changes with the switching of the fixation target presentation position. To do. Therefore, it is possible to accurately detect that the line of sight of the subject's eye has moved in accordance with at least switching of the fixation target presentation position. Therefore, according to the ophthalmologic apparatus 100, the fixation state of the eye to be examined can be easily and satisfactorily monitored.

  In the present embodiment, whether or not the gaze direction has changed is determined according to the magnitude relationship between the change amount of the gaze direction information before and after the fixation target presentation position is switched and the predetermined threshold value. Made. The threshold value is set to a large value with respect to the amount of change in the line-of-sight direction due to microscopic fixation. Such a threshold value can be set sufficiently small, for example, with respect to a change amount representing a change in the line-of-sight direction of about several degrees (for example, a viewing angle of about 5 °). Therefore, even if the interval between adjacent presentation positions is about several degrees in view angle, the fixation state of the eye to be examined can be monitored well.

  Further, when it is determined that the gaze direction of the eye to be examined has not changed before and after the fixation target presentation position is switched, a message indicating that there is a possibility of fixation failure is output from the monitor 97. As a result, in the above-described embodiment, the examiner can grasp that there is a risk of fixation failure, and can instruct the examiner to cause fixation. Therefore, in the imaging device 100, it is easy to capture an endothelial cell image in a state where the fixation is surely performed.

  In the present embodiment, since it is determined that the line-of-sight direction has changed by the above determination, at least a subsequent imaging operation including imaging of a corneal endothelial cell image (that is, an alignment operation and a light emission operation of the illumination light source 11). Any). Therefore, since the photographing operation is easily performed after the fixation is surely performed, it is easy to suppress re-taking of the photographing due to the fixation failure. Moreover, in the said embodiment, after determining with the said determination that the gaze direction changed, alignment in the presentation position of the fixation target at that time is performed. Therefore, re-alignment is also suppressed. As a result, according to the imaging device 100, a series of imaging times can be suppressed.

  As described above, the description has been given based on the embodiment, but the technology disclosed by the above embodiment may be modified as follows.

  For example, in the above embodiment, when a change in the line-of-sight direction accompanying switching of the fixation target presentation position is determined, the anterior segment image (observation image) obtained before switching and obtained after switching are obtained. One anterior segment image was used. Specifically, the CPU 91 detects a change in the line-of-sight direction information from the two anterior segment images. In order to obtain line-of-sight direction information before switching of the fixation target presentation position (that is, the first presentation position) or after switching (that is, the second presentation position), a plurality of anterior segment images are respectively obtained. May be used. For example, the imaging apparatus 1 acquires average line-of-sight direction information in a plurality of anterior segment images obtained when the fixation target is at the first presentation position (mainly by the CPU 91), and at the same time, Average line-of-sight direction information in a plurality of anterior segment images obtained when the visual target is at the second presentation position may be acquired, and changes in the average line-of-sight direction information may be detected. The average line-of-sight direction information is obtained by, for example, obtaining line-of-sight direction information for each image from a plurality of anterior segment images obtained continuously in a certain period, and further by taking the average of the obtained line-of-sight direction information. You may get it. By averaging the line-of-sight direction information, the effect of temporary movement in the line-of-sight direction due to microscopic movements such as microsaccade is easily suppressed. Therefore, the fixation state of the eye to be examined can be monitored better.

  In the above-described embodiment, the case has been described in which the line-of-sight direction information is detected as position information with respect to the corneal bright spot sp with the pupil center ic as a reference in the anterior segment image (observation image).

  In particular, in the above-described embodiment, the bright spot formed at the apex of the cornea is used as the cornea bright spot sp. However, the bright spot used to obtain the line-of-sight direction information may be a bright spot formed away from the top of the cornea, such as a bright spot for alignment (for example, at least one of i20 to i70 in FIG. 4). Good.

  The line-of-sight direction information may be information regarding the line of sight of the eye E, and may not necessarily be a value obtained based on the corneal bright spot. For example, in the case of detecting gaze direction information from the anterior ocular segment image, the ratio between the major axis a and the minor axis b of the ellipse when the pupil shape (or corneal shape) is approximated to an ellipse, and the angle of each axis Etc. can be used as line-of-sight direction information (see FIG. 9). In this case, as the inclination of the line of sight with respect to the front direction of the apparatus (for example, the optical axis L4) increases, the long axis a of the ellipse becomes longer than the short axis b. Therefore, for example, if the threshold is set as a ratio of the major axis a to the minor axis b, the value of the ratio of the major axis a to the minor axis b in the ellipse detected in the anterior segment image is greater than the threshold. When the value is small, it can be determined that the line-of-sight direction of the eye to be examined has not changed. In the above embodiment, the positional relationship between the pupil and the corneal bright spot, the pupil shape, and the like are calculated by the control unit 70 for each anterior segment image, and the presence / absence of a change in the gaze direction is determined based on the comparison of the values. Judgment. However, the method for determining the change in the line-of-sight direction is not necessarily limited to this. For example, the control unit 70 may obtain a correlation between observation images by image matching or the like, and may determine a change in the line-of-sight direction based on the correlation.

  Moreover, in the said embodiment, in order to provide the information regarding the fixation state of the eye E to at least one of the examiner and the examinee, the case where the monitor 97 is used as the information providing unit has been described. However, the present invention is not limited to providing information using information displayed on the monitor 97, and various means can be used. For example, any one of a fixation target and a speaker (not shown) may be used. For example, when notifying information indicating that there is a risk of fixation failure using a fixation target, the presentation mode of the fixation target presented to the eye to be examined at that time changes from the normal state You may make it make it. For example, the subject may be informed that there is a risk of fixation failure by switching the lighting state of the fixation lamp corresponding to the presenting position at that time. In this case, for example, the lighting state may be switched between constant lighting and blinking. In this way, it is considered that by switching the fixation mode of the fixation target, the attention of the subject can be attracted to the fixation target and further fixation can be promoted. Further, for example, a message indicating that there is a risk of fixation failure may be notified to the examiner and the subject by voice or the like from a speaker not shown. Further, information indicating that there is a risk of fixation failure due to a combination of a plurality of means such as a combination of a monitor 97 and a speaker may be notified to at least one of the examiner and the subject.

  In the present embodiment, the imaging apparatus 100 includes the internal fixation lamp and the external fixation lamp, but may be configured to include only one of them. In addition, each fixation lamp was configured to switch the presentation position of the fixation target with respect to the eye to be examined by switching one to be lit from a plurality of fixation lamps, but is not necessarily limited thereto, A configuration may be adopted in which the fixation position of the fixation target is switched by moving the fixation lamp in a direction crossing the optical axis L4.

  Further, in the imaging apparatus 100 of the above-described embodiment, when the fixation target presentation position is switched from the first presentation position to the second presentation position, in order to promote guidance of fixation to the second presentation position, The CPU 91 may perform control to switch the target presentation mode. The switching of the presentation mode can be, for example, switching of the color of the fixation target at the second presentation position, the blinking state, or the like. For example, in the fixation target color switching control, after the fixation target presentation position is switched to the second presentation position, the fixation target color is turned on with a color different from that at the time of shooting for a certain period of time. Also good. Further, the switching control of the blinking state of the fixation target is performed by turning off the fixation lamp for a certain time when the presentation position of the fixation target is switched from the first presentation position to the second presentation position, The fixation target may be presented at the presentation position. Further, after the fixation target presentation position is switched to the second presentation position, the fixation target at the second presentation position may blink for a certain period.

  In the imaging device 100 of the above-described embodiment, the third presentation position may be relayed when the fixation target presentation position is switched from the first presentation position to the second presentation position. That is, after switching from the first presentation position to the third presentation position, control for switching from the third presentation position to the second presentation position may be further performed. In this case, the third presentation position has a larger interval between the third presentation position and the second presentation position than the narrowest interval among the respective fixation target presentation positions. It may be a position set to. Alternatively, the third presentation position is a position that is set such that a larger interval is secured between the third presentation position and the second presentation position than the interval between the first presentation position and the second presentation position. There may be. Thus, by passing through the third presentation position, the presentation position of the fixation target can be greatly moved, and the subject can easily move in the line-of-sight direction. In this case, the fixation state of the subject is determined based on the change between the gaze direction information detected when the position is the first presentation position and the gaze direction information detected when the position is the second presentation position. It may be monitored by the CPU 91. Further, the CPU 91 monitors the fixation state of the subject based on the change between the gaze direction information detected when the position is the third presentation position and the gaze direction information detected when the position is the second presentation position. May be.

  In the above-described embodiment, when imaging of a corneal endothelial cell image is executed at each fixation target presentation position (S6, S12), the imaging device 100 is automatically based on the output signal from the detector 89. As described above, it is assumed that shooting is performed with focus. However, the present invention is not necessarily limited to this, and the focus adjustment may be manually performed by an examiner.

  In the above embodiment, a corneal endothelial cell imaging device has been described as an example of an ophthalmic device. However, the technique of the present disclosure is applied to other ophthalmic imaging devices for observing or imaging an eye to be examined. Can be applied. For example, the present invention can be applied to an apparatus having a function of photographing an anterior eye portion such as a Shine proof camera (for example, photographing by light emission), and photographing a fundus such as a fundus camera and a confocal laser ophthalmoscope (for example, emitting light). The present invention can also be applied to an apparatus having a function of photographing). Of course, the present invention can also be applied to an apparatus for observing both the anterior segment and the fundus, such as a slit lamp and a surgical microscope. Note that a fundus image can be used as an observation image in an imaging apparatus that captures a fundus image. In this case, in addition to the observation optical system in which the light emitted from the light source is projected toward the fundus of the eye to be examined and the fundus reflected light of the light is received by the photodetector, the imaging apparatus further includes a light An observation image forming unit (for example, an image processing IC or the like) that forms a fundus front image based on a light reception signal from the detector is provided. In this case, the line-of-sight position information may be detected from the fundus observation image formed in the observation image forming unit. In this case, an image at a shooting position corresponding to the direction of the line of sight is obtained as the observation image. Therefore, as the line-of-sight position information, information related to the observation image acquisition position (for example, position information of feature points such as macula in the fundus image or image information of the fundus image itself) can be used. Further, the amount of change in the line-of-sight position information can be obtained as information on the displacement between images. However, in an imaging device that captures an image of the fundus, if an anterior ocular segment observation optical system that acquires an anterior ocular segment image as an observation image is further provided, gaze direction information is detected from the anterior ocular segment image. Also good.

  Further, the technology of the present disclosure can be applied to an ophthalmologic apparatus (that is, an optometry apparatus) used for examining an eye to be examined in addition to the ophthalmologic photographing apparatus. For example, the present invention can be applied to various optometry apparatuses such as a perimeter, an axial length measuring apparatus, and a subjective optometry apparatus.

5 drive mechanism 10 cornea photographing optical system 10a illumination optical system 10b light receiving optical system 22 image sensor 51 front projection optical system 70 internal fixation optical systems 71a to 71i fixation lamp 75 external fixation optical systems 76a to 76f fixation lamp 80 front Eye observation optical system 90 control unit 91 CPU
97 Monitor E Eye to be examined

Claims (9)

A fixation optical system having a fixation target presented to the eye to be examined and capable of switching a presentation position of the fixation target in order to change a visual line direction of the eye to be examined;
Gaze direction information detecting means for detecting gaze direction information which is information relating to the gaze direction of the eye to be examined;
When the fixation target presentation position is switched from the first presentation position to a second presentation position different from the first presentation position, the line-of-sight direction of the eye to be inspected is changed according to the switching of the fixation target presentation position. An ophthalmologic apparatus comprising: a determination unit that determines whether or not a change has occurred based on a change in the gaze direction information before and after the presenting position of the fixation target is switched. When the determination means determines that the gaze direction of the eye to be examined has not changed before and after the presentation position of the fixation target is switched,
Output that outputs information indicating that there is a risk of fixation failure at the second presentation position from an information providing unit for providing information on the fixation state of the eye to at least one of the examiner and the subject. The ophthalmologic apparatus according to claim 1, further comprising a control unit. The line-of-sight direction information detecting means includes
An observation optical system for acquiring an observation image used for alignment, irradiating light to be examined from a light source toward the subject's eye, and light reflected from a portion of the subject's eye irradiated with the light An observation optical system that receives light with a detector;
An observation image forming means for forming an observation image of the eye to be inspected based on a light reception signal from the photodetector;
Information acquisition means for acquiring gaze direction information based on the observation image formed by the observation image forming means,
The information acquisition means acquires first gaze direction information from a first observation image that is the observation image obtained when the fixation position of the fixation target is the first presentation position, and further, the fixation Obtaining second gaze direction information from a second observation image, which is an observation image obtained when the target presentation position is the second presentation position;
The determination means obtains a change amount related to the gaze direction information determined by the first gaze direction information and the second gaze direction information, and the gaze direction of the eye to be changed changes with the switching of the presentation position of the fixation target. The ophthalmologic apparatus according to claim 1, wherein it is determined based on the amount of change.   The determination means compares the amount of change in the line of sight with a threshold value set to a large value with respect to the displacement in the line of sight due to fixation fine movement, thereby switching the position of the fixation target when the fixation target is switched. The ophthalmologic apparatus according to claim 3, wherein it is determined whether or not the gaze direction of the optometry has changed. The observation optical system projects light from the light source toward the anterior ocular segment of the subject's eye, and receives the anterior ocular segment reflected light by the light using the photodetector.
The observation image forming means forms an anterior ocular segment front image as the observation image;
5. The ophthalmic apparatus according to claim 3, wherein the information acquisition unit acquires line-of-sight direction information from information on at least one part of a pupil and a cornea in an anterior ocular segment front image. The observation optical system projects light emitted from the light source toward the fundus of the eye to be examined, and receives fundus reflected light from the light using the photodetector.
The observation image forming means forms a fundus front image as the observation image;
5. The ophthalmologic apparatus according to claim 3, wherein the information acquisition unit acquires the line-of-sight direction information as information related to a photographing position at the fundus in the fundus front image. A second light, which is light used for optometry of the eye to be examined, is applied to at least the eye to be examined in each of the case where the fixation target presentation position is the first presentation position and the second presentation position. Two optical systems;
The determination is made when the fixation target presentation position is switched from the first presentation position to the second presentation position, and the line-of-sight direction of the eye to be examined changes as the fixation target presentation position is switched. The ophthalmologic apparatus according to claim 1, further comprising: an operation executing unit that executes a light emission operation using the second optical system for optometry after being determined by the unit. The second optical system receives a second light projecting optical system that irradiates the second light as illumination light toward the cornea of the eye to be examined, and the reflected light of the second light from the cornea including endothelial cells. A second light receiving optical system having a second photodetector;
The photographic image forming means for acquiring a photographic image containing the endothelial cells of the cornea based on a light reception signal output from the second photodetector in association with the light emission operation. 7. The ophthalmic apparatus according to 7. An alignment drive mechanism for performing alignment by moving the optical system of the ophthalmologic apparatus relative to the eye to be examined;
The operation execution means further controls the alignment drive mechanism after the determination means determines that the line-of-sight direction of the eye to be examined has changed in accordance with switching of the fixation target presentation position, and then controls the alignment driving mechanism. The ophthalmologic apparatus according to claim 7, wherein the light emission operation is performed after performing alignment at a presentation position.

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