JP5871089B2 - Corneal endothelial cell imaging device - Google Patents

Description

  The present invention relates to a corneal endothelial cell imaging apparatus that images a cell image of a corneal endothelium of a subject's eye.

  2. Description of the Related Art Conventionally, there is known an apparatus that irradiates illumination light from an illumination light source obliquely toward a cornea, receives a reflected light beam from the cornea by an image sensor, and obtains a cell image of the corneal endothelium without contact ( Patent Document 1).

JP-A-8-206080

An object of the present invention is to provide a corneal endothelial cell imaging apparatus capable of acquiring an endothelium image at the center of the cornea, an endothelium image near the center of the cornea, and an endothelial image outside the vicinity of the center of the cornea. .

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) an illumination optical system for irradiating illumination light from an illumination light source obliquely toward the subject's cornea;
An imaging optical system for receiving reflected light from the cornea containing corneal endothelial cells by an imaging device and acquiring an endothelial cell image of the cornea;
An internal fixation optical system comprising: a central fixation lamp; and a plurality of neighboring fixation lamps arranged on the same circumference around the central fixation lamp;
An external fixation optical system comprising a plurality of peripheral fixation lamps arranged on the same circumference around the central fixation lamp, and
The plurality of near fixation lamps are 0 degree (3 o'clock) , 45 degrees, 90 degrees (12 o'clock) , 135 degrees, 180 degrees (9 o'clock) , 225 degrees, 270 degrees (6 degrees ) as viewed from the subject. ) , Arranged at each predetermined position of 315 degrees, provided for acquiring an endothelial cell image in a region near the central portion of the cornea of the eye to be examined,
The plurality of peripheral fixation lamps are arranged at predetermined positions at 2 o'clock, 4 o'clock, 6 o'clock, 8 o'clock, 10 o'clock, and 12 o'clock as seen from the subject, and are located closer to the vicinity of the central portion of the cornea Furthermore, it is provided to acquire the outer endothelial cell image,
Each endothelial cell image acquired by the plurality of near fixation lamps arranged at 0, 45, 135, 180, 225, and 315 degrees is 2 o'clock, 4 o'clock, 8 o'clock, 10 o'clock, The axial angle on the cornea is different from each of the endothelial cell images acquired by the plurality of peripheral fixation lamps arranged at the time position.

According to the present invention, it is possible to acquire an endothelium image at the center of the cornea, an endothelium image near the center of the cornea, and an endothelium image outside the vicinity of the center of the cornea.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external side configuration diagram of a corneal endothelial cell imaging apparatus according to the present embodiment.

  The device 100 is a so-called stationary device, and is a base 1, a face support unit 2 attached to the base 1, and a movable base provided so as to be movable on the base 1 by a sliding mechanism not shown. 3 and a photographing unit (device main body) 4 that is provided so as to be movable with respect to the movable table 3 and accommodates a photographing system and an optical system described later.

  The imaging unit 4 is moved 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 an XYZ driving unit 6 provided on the moving table 3. The movable table 3 is moved in the XZ direction on the base 1 by operating the joystick 5. Further, when the examiner rotates the rotary knob 5 a, the photographing unit 4 is moved in the Y direction by the Y drive of the XYZ drive unit 6. A start switch 5 b is provided on the top of the joystick 5. The display monitor 95 is provided on the examiner side of the imaging unit 4. In this embodiment, the photographing unit 4 is moved relative to the eye E by a sliding mechanism (not shown) or the XYZ driving unit 6.

  In addition, as a structure which moves the imaging | photography part 4, the structure which moves the imaging | photography part 4 with respect to a right-and-left eye by the drive of the motor of the drive part 6 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 5 may be sufficient as this apparatus.

  FIG. 2 is a schematic configuration diagram illustrating an example of an optical arrangement and a control system configuration when the optical system housed in the photographing unit 4 is viewed from above. FIG. 3 is a view of the first projection optical system and the second projection optical system as viewed from the subject side. The overall configuration of the optical system includes an illumination optical system 10, an imaging optical system 30, a front projection optical system 50, first projection optical systems 60a and 60b, second projection optical systems 65a to 65d (see FIG. 3), and internal fixation optics. A system 70a to 70g, an external fixation optical system 75a to 75f, an anterior ocular segment observation optical system 80, and a Z alignment detection optical system 85.

  The illumination optical system 10 irradiates illumination light from the illumination light source 12 obliquely toward the cornea Ec. The illumination optical system 10 includes an illumination light source (eg, visible LED, flash lamp) 12 that emits visible light for endothelium imaging, a condensing lens 14, a slit plate 16, a dichroic mirror 18 that reflects and transmits infrared light, and light projection. A lens 20. The light emitted from the illumination light source 12 illuminates the slit plate 16 via the condenser lens 14. Then, the slit light that has passed through the slit plate 16 is converged by the light projecting lens 20 via the dichroic mirror 18 and irradiated onto the cornea. Here, the slit plate 16 and the cornea Ec are disposed at a substantially conjugate position with respect to the objective lens 20.

  The imaging optical system 30 obtains an endothelial cell image by receiving reflected light from the cornea Ec containing endothelial cells with an imaging element. The imaging optical system 30 is symmetrical with the illumination optical system 10 with respect to the optical axis L1, and includes an objective lens 32, a visible light reflecting / infrared transmitting dichroic mirror 34, a mask 35, a first imaging lens 36, and a total reflection mirror 38. The second imaging lens 42, a first two-dimensional imaging device dedicated for acquiring an endothelial cell image (for example, a two-dimensional CCD image sensor (Charge coupled device image sensor), a two-dimensional CMOS (Complementary Metal Oxide Semiconductor Image). Sensor), etc.) 44. The mask 35 is disposed at a position substantially conjugate with the cornea Ec with respect to the objective lens 32. The first imaging lens 36 and the second imaging lens 42 form an imaging optical system that forms an endothelial image on the image sensor 44. The imaging element 44 is disposed at a position substantially conjugate with the cornea Ec with respect to the lens system of the imaging optical system 30.

  The cornea-reflected light from the illumination optical system 10 is directed in the direction of the optical axis L3 (oblique direction), converged by the objective lens 32, reflected by the dichroic mirror 34, temporarily imaged by the mask 35, and an endothelial cell image is obtained. Light that becomes noise during acquisition is blocked. Then, the light that has passed through the mask 35 is imaged on the two-dimensional imaging device 44 via the first imaging lens 36, the total reflection mirror 38, and the second imaging lens 42. Thereby, a high-magnification corneal endothelial cell image is acquired. The output of the image sensor 44 is connected to the control unit 90, and the acquired cell image is stored in the memory 92. The cell image is displayed on the monitor 95.

  The front projection optical system 50 projects the alignment index from the front toward the cornea Ec. The front projection optical system 50 includes an infrared light source 51, a light projection lens 53, and a half mirror 55, and projects infrared light for XY alignment detection onto the cornea Ec from the direction of the observation optical axis L1. Infrared light emitted from the light source 51 is converted into a parallel light beam by the light projecting lens 53, then reflected by the half mirror 55, and projected onto the center of the cornea Ec to form an index i10 (see FIG. 4). ).

  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. 2). 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 to form the indices i20 and i30 (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. Further, 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 internal fixation optical systems 70a to 70g project a fixation target from the inside to the eye E. The internal fixation optical systems 70a to 70g include visible light sources (fixation lamps) 71a to 71g, a light projection lens 73, and a visible reflection / infrared transmission dichroic mirror 74. Visible light emitted from the light source 71 is converted into a parallel light beam by the light projection lens 73, reflected by the dichroic mirror 74, and projected onto the fundus of the eye E.

  The internal fixation optical systems 70a to 70i have a plurality of fixation targets arranged at different positions with respect to the direction orthogonal to the optical axis L4, and guide the fixation direction of the eye E in each direction. The internal fixation optical systems 70 a to 70 i are provided inside the photographing unit 4. For example, the visible light source (fixation lamp) 71a is disposed in the vicinity of the optical axis L4, and is used to obtain an endothelial image of the central part of the cornea by guiding the eye E in the front direction. The plurality of visible light sources (fixation lamps) 71b to 71i are arranged on the same circumference with the optical axis L4 as the center, and are arranged at predetermined angles as viewed from the subject. In 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. The visible light sources 71b to 71i are used to obtain an endothelium image around the center of the cornea by guiding the visual line direction of the eye E to the peripheral direction. That is, the internal fixation optical systems 71b to 71i are first fixation optical systems that guide the line-of-sight direction of the eye E to a first viewing angle (for example, a viewing angle of 5 °) in order to acquire an endothelial image near the center of the cornea. Used. As the first viewing angle, for example, a viewing angle of 3 ° to 10 ° is set in order to obtain an endothelial image near the center of the cornea. As the deflection angle (viewing angle) of the first fixation optical system, the degree of continuity is ensured between the endothelium image at the center of the cornea and each endothelium image near the center of the cornea with respect to the imaging site (the imaging sites partially overlap). , Or the imaging part is substantially continuous). As the fixation optical system, the fixation position is adjusted by the lighting (flashing) position of the LED arranged at each position, and the fixation target is displayed by changing the display position of the fixation target displayed on the small display. A configuration for adjusting the position is conceivable.

  The external fixation optical systems 75a to 75f project fixation targets from the outside. 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 photographing unit 3 and on the eye E side. For example, the external fixation optical systems 75a to 75f have visible light sources (fixation lamps) 76a to 76f, and are 2 o'clock and 4 o'clock as viewed from the subject on the same circumference around the optical axis L1. It is arranged at each of the hour, 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. The external fixation optical systems 75a to 75f acquire the endothelial image of the peripheral portion of the cornea that is further outward from the vicinity of the cornea center, and therefore, the second viewing angle (for example, the viewing angle 25) is larger than the first viewing angle. Used as a second fixation optical system for guiding to (°). As the second viewing angle, for example, in order to obtain an endothelial image around the cornea, the viewing angle is set within a range of a viewing angle of 20 ° to 35 °.

  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.

  Returning to FIG. The anterior segment observation optical system 80 observes the anterior segment image from the front. The anterior ocular segment observation optical system 80 has an objective lens 82 and a two-dimensional image sensor 84 for acquiring an anterior ocular segment front image, and has a second image sensor 84 different from the first image sensor 44. Then, the anterior segment image and the alignment index are captured by the second image sensor 84. As the two-dimensional image sensor 84, for example, a two-dimensional CCD image sensor or a two-dimensional CMOS is used.

  The anterior segment illuminated by an anterior segment illumination light source (not shown) is imaged by the two-dimensional imaging device 84 via the dichroic mirror 75, the half mirror 55, and the objective lens 82. Similarly, the corneal reflection images by the front projection optical system 50, the first projection optical systems 60a and 60b, and the second projection optical systems 65a to 65d are received by the two-dimensional imaging device 84.

  The output of the image sensor 84 is connected to the control unit 90, and the anterior segment image captured by the image sensor 84 is displayed on the monitor 95 as shown in FIG. Note that the reticle LT displayed electronically on the monitor 95 indicates a reference for XY alignment. Note that the observation optical system 80 also serves as a detection optical system for detecting the alignment state of the imaging unit 4 with respect to the eye E. In the above configuration, the image sensor for obtaining the endothelium image and the image sensor for obtaining the front image of the anterior segment are separated, but the endothelium image and the front image of the anterior segment are obtained by the same image sensor. The structure which acquires may be sufficient.

  The Z alignment detection optical system 85 detects the alignment state of the imaging unit 4 with respect to the eye E in the Z direction. The Z alignment detection optical system 85 includes a light projecting optical system 85a that projects a detection light beam from an oblique direction toward the cornea Ec, and a light receiving optical system 85b that receives a corneal reflected light beam by the light projecting optical system 85a. . The optical axis L2 of the light projecting optical system 85a and the optical axis L3 of the light receiving optical system 85b are arranged at positions symmetrical with respect to the observation optical axis L1.

  The light projecting optical system 85a includes, for example, an illumination light source 86 that emits infrared light, a condensing lens 87, a pinhole plate 88, and a lens 20. Here, the pinhole plate 88 and the cornea Ec are disposed at a substantially conjugate position with respect to the lens 20. The light receiving optical system 85 b includes, for example, a lens 32 and a one-dimensional light receiving element (line sensor) 89. Here, the one-dimensional light receiving element 89 and the cornea Ec are disposed at a substantially conjugate position with respect to the lens 32.

  The infrared light emitted from the light source 86 illuminates the pinhole plate 88 through the condenser lens 87. Then, the light that has passed through the opening of the pinhole plate 88 is projected onto the cornea Ec through the lens 20. The corneal reflection light is received by the light receiving element 89 via the lens 32 and the dichroic mirror 34.

  The output of the light receiving element 89 is connected to the control unit 90 and used for Z alignment detection with respect to the eye E. Here, the light receiving position of the alignment light flux received on the light receiving element 89 is changed depending on the positional relationship between the imaging unit 4 and the eye E in the Z direction. For example, the control unit 90 detects the position of the corneal reflected light in the detection signal from the light receiving element 89 and detects the alignment state in the Z direction. The alignment detection using the light receiving element 89 is used for precise alignment with the eye E.

  The control unit 90 controls the entire apparatus. The control unit 90 includes a rotary knob 5a, a start switch 5b, an XYZ driving unit 6, two-dimensional imaging devices 44 and 84, each light source, a memory 92 as a storage unit, a monitor 95, an operation unit 96, and left and right eye detectors. 98 is connected.

  The monitor 95 is a touch panel monitor (touch panel display), and the examiner can set various conditions by operating buttons displayed on the monitor 95 (see, for example, FIG. 10).

  For example, the control unit 90 controls the display on the monitor 95. In addition, the control unit 90 detects the alignment state of the imaging unit 4 with respect to the eye E in the XYZ directions based on the light reception result of the alignment index. And the control part 90 outputs the signal which instruct | indicates the movement of the imaging | photography part 4 based on the detection result. Further, the control unit 90 detects the alignment state of the photographing unit 4 in the Z direction with respect to the eye E based on the light reception result of the light receiving element 89.

  The operation of the apparatus having the above configuration will be described. In the apparatus 100, after performing XYZ alignment, a plurality of endothelial cells are continuously photographed while the imaging unit 4 is advanced. Hereinafter, each operation will be described in detail.

<XYZ alignment>
4A and 4B are diagrams showing an example of an anterior ocular segment observation screen when imaging the inner skin of the cornea, FIG. 4A is a display example when there is misalignment, and FIG. It is an example of a display in a state.

  In this case, the light source 71 is turned on and the fixation direction of the eye E is guided to the front. First, the examiner causes the subject to gaze at the fixation target. Further, the imaging unit 4 is aligned with the eye E while observing the anterior segment image displayed on the monitor 95.

  When rough alignment (manual alignment by the examiner until the indicators i40, i50, i60, and i70 are displayed on the monitor 95) is performed as described above, as shown in FIG. An image is detected on the light receiving surface of the image sensor 64. The control unit 90 searches for a bright spot from the upper left coordinate position of the image toward the lower right side of the screen. When the indices i40, i50, i60, i70 are detected, the control unit 90 detects the position of the detected bright spot.

  Then, the control unit 90 detects the center position of the rectangle including the indices i40, i50, i60, and i70 as a substantially corneal apex, and detects the misalignment direction / deviation amount of the imaging unit 4 with respect to the eye E in the XY directions. Then, the control unit 90 controls the driving of the driving unit 6 and moves the photographing unit 4 in the XY directions so that the alignment deviation falls within a predetermined alignment allowable range (for example, a range in which the index i10 is detected). This enables automatic alignment over a wide range.

  When the photographing unit 4 is moved and the index i10 is detected as described above, the control unit 90 ends the alignment using the indices i40 to i70 and performs the alignment using the index i10. Here, the control unit 90 determines the index i10 and the indices i40 to i70 from the positional relationship.

  Then, the control unit 90 detects the coordinate position of the index i10 as a substantially corneal apex, and detects the misalignment direction / deviation amount of the imaging unit 4 with respect to the eye E in the XY directions. Then, the control unit 90 controls the driving of the driving unit 6 and moves the imaging unit 4 in the XY direction so that the alignment deviation falls within a predetermined alignment allowable range (for example, the index i10 is located in the reticle LT). Let

  Further, when the index i10 is detected as described above, the indices i20 and i30 at infinity are similarly detected. Therefore, the control unit 90 compares the interval between the infinite indices i20 and i30 detected as described above and the distance between the finite indices i60 and i70 to determine the alignment deviation direction / deviation amount in the Z direction. Obtained (first alignment detection). Then, the control unit 90 determines that the alignment deviation of the imaging unit 4 with respect to the eye E in the Z direction is within a predetermined alignment allowable range (for example, the central luminescent spot of the infinite indices i20 and i30 and the central luminescent spot of the finite indices i60 and i70 The photographing unit 4 is moved in the Z direction so that the difference from the point is within plus or minus one pixel (dimension is about ± 0.1 mm) (first automatic alignment).

  In this case, when the measuring unit 3 is displaced in the working distance direction, the control unit 90 does not change the interval between the infinity indices i20 and i30 described above, whereas the image of the finite index images i60 and i70. Using the characteristic that the interval changes, 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. Also, the Z alignment may be detected based on the index distance (index height) from the optical axis L1.

  Then, when it is determined that the alignment state is appropriate in the first Z alignment detection, the control unit 90 stops the operation of the first automatic alignment and performs the second Z alignment detection using the detection optical system 85 and the detection thereof. A second automatic alignment based on the result is activated.

  The controller 90 turns on the light source 86 and projects an alignment light beam onto the cornea Ec (the light source 86 may be turned on in advance), and detects the corneal reflected light beam with the light receiving element 89. Then, the control unit 90 controls the driving of the driving unit 6 based on the light reception result from the light receiving element 89 and moves the photographing unit 4 in the Z direction.

  For example, the control unit 90 detects the peak P corresponding to the reflected light beam from the corneal epithelium based on the light reception signal output from the light receiving element 89, and detects the position Pz of the epithelial peak on the light receiving element 89 (FIG. 5). reference). Then, the control unit 90 drives the drive unit 6 so that the peak of the light reception signal due to the reflected light beam from the epithelium is at a predetermined position (for example, the center position) on the light receiving element 89.

  If the alignment state in the XYZ directions satisfies the alignment completion condition by the alignment operation described above, the control unit 90 determines that the alignment in the XYZ directions is matched, and issues a trigger signal.

<Photographing endothelial cells>
When the trigger signal is generated, the control unit 90 continuously turns on the illumination light source 12 and acquires a corneal endothelial cell image by visible illumination light with the two-dimensional imaging device 44. At this time, it is preferable that the control unit 90 causes the light source 12 to emit light with an amount of light such that epithelial reflected light is detected and endothelial reflected light is not detected. Thereafter, the control unit 90 turns on the light source 12 and controls driving of the driving unit 6 to advance the photographing unit 4 toward the eye E. During the movement of the photographing unit 4 in the Z direction, the control unit 90 continues the automatic alignment operation (tracking control using the image sensor 84) in the XY directions.

  The control unit 90 detects an output image from the image sensor 44 and controls the light source 12 and the drive unit 6 based on the detection result. FIG. 6 is a diagram illustrating an example of determining the light reception state of the corneal image based on the output image from the image sensor 44. In FIG. 6, the central white rectangular area corresponds to the opening of the mask 35 disposed in front of the image sensor 44, and the black hatches on the left and right correspond to the light shielding part of the mask 35.

  For example, the control unit 90 sets a first detection region Lc1 and a second detection region Lc2 that extend in a direction orthogonal to the thickness direction of the cornea (the Z direction in FIG. 6) in order to detect the light reception state of the cornea image. . The first detection region Lc1 is set for detecting the light receiving state of epithelial reflected light, and the second detection region Lc2 is set for detecting the light receiving state of endothelial reflected light. The control unit 90 calculates the total luminance value SLC1 of each pixel in the first detection region Lc1. In addition, the total luminance value SLC2 of each pixel in the second detection region Lc2 is calculated.

  7A to 7C are diagrams showing changes in the light reception state of the corneal reflection light when the imaging unit 4 is advanced, and FIGS. 8A and 8B are total values SLC1 and SLC2 when the imaging unit 4 is advanced. It is a graph showing the change of chronologically. 8A corresponds to the total value SLC1, and FIG. 8B corresponds to the total value SLC2.

  FIG. 7A is a diagram when alignment in the XYZ directions is completed. At this time, the epithelial reflected light Ep is received on the first region Lc1. For this reason, as the first total value SLC1, a high value corresponding to epithelial reflection is calculated (see FIG. 8A).

  And if the imaging | photography part 4 is advanced, epithelial reflected light Ep will be moved to the right direction of the paper surface of FIG. When the epithelial reflected light Ep passes the detection region Lc1, the total value SLC1 is greatly reduced (see the slope A in FIGS. 7B and 8A). Then, when the total value SLC1 falls below the predetermined threshold value S1, the control unit 90 increases the light amount of the light source 12 to the extent that the endothelial image appears in the output image from the image sensor 44. Thereby, the endothelial reflected light En can be detected by the image sensor 44.

  After the light amount of the light source 12 is increased, the control unit 90 continues the forward operation of the imaging unit 4 and stores the images continuously output from the imaging element 44 in the memory 92 as needed. The two-dimensional imaging device 44 outputs an imaging signal to the control unit 90 as needed in accordance with the frame rate. Thereby, a plurality (for example, about 30 to 40) of captured images of the endothelium are acquired in 1 to 2 seconds. And the control part 90 memorize | stores in the memory 92 the image which satisfy | fills certain conditions (for example, an endothelial cell image is acquired appropriately) as a still image among output images. Thereby, an endothelial cell image is photographed. In this case, the controller 90 may store a predetermined number set in advance in the memory 92. Then, the control unit 90 outputs the captured image stored in the memory 92 to the monitor 95.

  When the imaging unit 4 is moved forward, the endothelial reflected light En is moved to the right in the image (see FIGS. 7A to 7C). When the endothelial reflected light En reaches the second detection region Lc2, the total value SLC2 increases (see the slope B in FIG. 8B). A high value is positioned while the endothelial reflected light En is received on the second detection region Lc2. Further, when the imaging unit 4 is moved forward and the endothelial reflected light En passes the detection region Lc2, the total value SLC2 is greatly reduced (see the slope C in FIGS. 7C and 8B). When the total value falls below the predetermined threshold value S2, the control unit 90 dims the light source 12 (including turning off the light), stops the driving of the driving unit 6, and stops the forward movement operation of the photographing unit 4.

  In addition, as a method of causing the light source 12 to emit light continuously, a method of continuously flashing the light source 12 is included in addition to a method of always lighting the light source 12. When the light source 12 is continuously blinked, for example, the control unit 90 blinks so that a plurality of endothelial images can be acquired while the imaging unit 4 is moving. Further, the light source 12 may blink continuously in synchronization with the frame rate of the two-dimensional image sensor 44. For example, when the imaging time of one sheet is 30 ms, the light source 12 is turned on for several ms from the start of image acquisition, and then turned off. Then, when the acquisition of the next image is started, the light source 12 is turned on. That is, such a blinking operation is repeated.

  The control unit 90 is not limited to these, and may be any control (including continuous light emission of course) that causes the light source 12 to emit light a plurality of times so that a plurality of endothelial images can be obtained by the imaging device 44.

<Measurement of corneal thickness>
The controller 90 obtains the corneal thickness of the eye E based on the output of the light receiving element 89 during the above-described endothelial image photographing operation. For example, the control unit 90 detects the position S2z of the second light reception signal S2 corresponding to the reflection on the back surface of the cornea Ec (see FIG. 9). Then, the control unit 90 measures the corneal thickness using the light receiving signal output from the light receiving element 89 when the position S2z of the second light receiving signal S2 reaches a predetermined position (focus position) on the light receiving element 89. To do. The control unit 90 extracts, from the light reception signal output from the light receiving element 89, a first light reception signal S1 corresponding to reflection on the surface of the cornea Ec and a second light reception signal S2 corresponding to reflection on the back surface of the cornea Ec. To do. Then, the control unit 90 calculates a distance D (interval) between the extracted first light reception signal S1 and second light reception signal S2. Each received light signal is extracted, for example, by edge detection processing for the luminance distribution. Note that the control unit 90 may calculate the distance between the two peaks based on the output of the light receiving element 89 and calculate the corneal thickness from the calculated distance.

  Thereafter, the control unit 90 converts the calculated distance D into a measured value of the corneal thickness of the eye E using at least one of an arithmetic expression and a table. In the case of an arithmetic expression, for example, the arithmetic expression is created by optical simulation or the like in consideration of the difference in refractive index between air and cornea, the difference in corneal curvature, and the like. In the case of a table, for example, the table is created by calibration using known eyes (for example, model eyes) having different thicknesses. An arithmetic expression, a table, and the like are stored in the memory 92 in advance. The measurement result of the corneal thickness is stored in the memory 92 in a state associated with the endothelial image data.

<Acquisition of anterior segment image>
The control unit 90 acquires an anterior ocular segment image based on the output from the image sensor 84 during the above-described endothelial image capturing operation. For example, when the alignment state in the XYZ directions detected as described above satisfies the alignment completion condition, the control unit 90 stores a still image of the anterior segment image captured by the image sensor 84 in the memory 92. In this case, the anterior segment image data is stored in the memory 92 in a state associated with the endothelial image data.

  An example of the display layout of the monitor 95 in the apparatus according to this embodiment is shown below. In general, the control unit 90 stores the endothelial image acquired at each fixation position by the imaging optical system 30 in the memory 92 in association with fixation position information in the fixation optical system.

  The control unit 90 displays a front image of the anterior segment acquired by the observation optical system 80 on the screen of the monitor 95 as a moving image in order to configure an imaging screen of the endothelial image, while a plurality of images stored in the memory 92 are displayed. The endothelium image is displayed as a still image on the same screen of the monitor 95, and fixation position information is given to each of the endothelium images displayed on the monitor 95 (see FIG. 10).

  For example, the control unit 90 displays the front image of the anterior segment at the center of the screen of the monitor 95 and a plurality of endothelial images as thumbnail images around the screen of the monitor 95. For example, thumbnail images are displayed on at least one of the top, bottom, left, and right of the front image of the anterior segment.

  Further, the control unit 90 provides a plurality of endothelium image display areas at the left and right ends of the anterior segment front image display area, displays the left eye endothelium image as a thumbnail image in one area, and displays the right image in the other area. The endothelium image of the eye is displayed as a thumbnail image. The display mode is not limited to the above, and a plurality of endothelial image display areas may be provided either above or below the display area of the anterior ocular segment front image, and the control unit 90 sets the endothelial image display areas to the left and right. The left eye endothelial image is displayed as a thumbnail image in one area, and the right eye endothelial image is displayed as a thumbnail image in the other area.

  In this case, the apparatus is provided with a configuration for detecting whether the endothelial image acquired by the imaging optical system 30 is the left or right eye. As a configuration for detecting the left and right eyes, for example, a position sensor (an optical sensor, a magnetic sensor, or the like) that detects whether the imaging unit 3 is on the left or right with respect to the base 1 is provided, and detection of the sensor is performed. The left and right eyes are discriminated based on the signal. Further, the left and right eyes are discriminated based on an operation signal from a left and right eye selection switch provided in the operation unit 96. In addition to the above configuration, a known configuration is used as the configuration for detecting the left and right eyes.

<Shooting screen>
FIG. 10 is a diagram illustrating an example of a shooting screen. On the screen, an eye image display screen 300, a fixation lamp button 302, an R / L display 304, a fixation lamp display 306, an image switching button 307, an imaging result display 308, and an imaging result button 310 are displayed.

  The eye image display screen 300 is arranged at the center of the screen of the monitor 95, and a captured image (anterior eye front image) of the two-dimensional image sensor 84 or a captured image (endothelium image) of the two-dimensional image sensor 44 is a moving image in real time. Displayed as an image. The image switching button 307 is used to switch the eye image display screen 300 between a first screen that displays an anterior ocular segment front image and a second screen that displays an endothelial image. The first screen is used for alignment with the eye E and observation of the front image of the anterior segment of the eye E. The second image is used when manually focusing on the endothelium. The fixation lamp display 306 indicates the position of the fixation lamp that is currently lit. The fixation lamp display (fixation position display) 306 is displayed so as to be superimposed on the captured image of the eye image display screen 300, for example.

  The fixation lamp button 302 is a button for displaying a fixation lamp screen window for selecting a lighting position of the fixation lamp. When the fixation lamp button 302 is pressed, the fixation lamp screen is displayed superimposed on the shooting screen, and the examiner sets the lighting position of the fixation lamp.

  FIG. 11 is a diagram illustrating an example of a fixation lamp screen. The fixation lamp at the selected position is turned on (or flashes). The button C in FIG. 11 corresponds to a visible light source 71a (initial setting position) for obtaining an image of the center of the cornea at a viewing angle of 0. Further, the eight buttons in the center area in FIG. 11 correspond to the visible light sources 71b to 71i for obtaining an endothelial image in the vicinity of the cornea center. Further, the six buttons in the peripheral area in FIG. 11 correspond to the visible light sources 76a to 76f for obtaining the endothelial images around the cornea. The control unit 90 discriminates and displays the selected fixation lamp by painting a radio button corresponding to the selected fixation lamp. Based on these operation signals, fixation position information of the endothelial image to be photographed is acquired.

  The R / L display 304 indicates whether the eye image displayed on the eye image display screen 300 is the left or right eye. The control unit 90 determines the left and right eyes of the photographed eye based on the detection signal from the left and right eye detector 98 provided in the apparatus 100, and controls the display state of the R / L display 304 according to the determination result ( Color, frame, lighting, etc.). For example, when the photographing eye is the right eye, the R portion is colored.

  In the imaging result displays 308R and 308L, the imaging results of the endothelial images are displayed in a list divided into left and right eyes in the imaging order. For example, one imaging result 308 is an imaging result acquired based on one endothelial imaging operation (endothelium imaging trigger). In this embodiment, the thumbnail SN of the endothelial image and a fixed image corresponding to the endothelial image are displayed. A combination of the viewing lamp display F and the corneal thickness value CT measured simultaneously with the endothelial image is formed as one set. When a plurality of imaging results are acquired for the left and right eyes, each imaging result 308 is displayed separately for each of the left and right eyes. In the upper part of the display column of the photographing result display 308, the number of photographing is displayed for each of the left and right eyes.

  The imaging result displays 308R and 308L are displayed at both ends of the eye image display screen 300, and the imaging results are displayed separately for the left and right eyes. For example, in the display area formed on the left side of the eye image display screen 300, the right eye imaging result 308R is displayed, and in the display area formed on the right side of the eye image display screen 300, the left eye imaging result 308L is displayed. Is done. Note that the R / L display 304 also serves as a left / right eye discrimination display regarding the imaging results 308R and 308L.

  The imaging result button 310 is used as a switch for shifting from the imaging screen to the endothelial image imaging result screen. That is, when the shooting result button 310 is pressed, shooting is terminated and a shooting result screen (see FIGS. 13A and 13B) is displayed.

  In the shooting screen, the examiner aligns the shooting unit 4 with respect to the eye E while viewing the eye image display screen 300 and sets the position of the fixation lamp using the fixation lamp button 302. In response to the trigger for acquiring the endothelial image, the control unit 90 switches the display screen 300 to the endothelium observation image and acquires a plurality of images continuously while moving the imaging unit 4 in a predetermined direction.

  Upon completion of shooting, the screen shifts to an image selection screen (see FIG. 12). FIG. 12 is a diagram illustrating an example of an image selection screen.

  On the screen, an enlarged screen 400, a thumbnail display 402, a fixation lamp display 404, an anterior ocular segment image display 406, a corneal thickness display 408, a confirmation button 410, a page button 412, and a re-shooting button 414 are displayed.

  The examiner presses and selects the image most suitable for analysis from the endothelial images displayed in the thumbnail display 402. The selected image is displayed on the enlarged screen 400 on the left side of the screen. The control unit 90 highlights and displays the selected image so that the selected image can be distinguished from other images (for example, color the figure number, surround the image with a frame, etc.). The fixation lamp display 404 indicates fixation lamp information corresponding to the selected endothelial image. The anterior segment image display 406 is an anterior segment image acquired at the same time as the selected endothelial image. The corneal thickness value CT indicates a corneal thickness value measured simultaneously with the selected endothelial image.

  In the thumbnail display 402, among a plurality of acquired endothelial images, a plurality of endothelial images determined to be good by image processing are displayed in the order in which the apparatus determines that they are appropriate (see numbers). The selection of the endothelium image displayed on the monitor 95 is calculated by the control unit 90 and sorted in a good order (for example, the order in which cells are widely shown).

  When the confirmation button 410 is pressed, the selected image is confirmed as an image for analysis and returned to the shooting screen. When the page button 412 is pressed, the thumbnail display 402 is switched to the next sequential image. A plurality of endothelium images stored in the memory 92 by one endothelium imaging operation are confirmed by page switching. Further, when the re-shooting button 414 is pressed, the shooting screen is switched to perform re-shooting. Then, the image data displayed on the image selection screen is discarded.

  When returning to the imaging screen (see FIG. 10), the examiner changes the position of the fixation lamp using the fixation lamp button 302 and aligns the eye E while viewing the eye image display screen 300. In this case, the examiner can confirm the imaging position of the acquired endothelial image by the fixation lamp display F given to each thumbnail SN. Furthermore, since the thumbnail SN of the endothelial image is displayed together with the fixation lamp display F, it can be intuitively confirmed that the endothelial image corresponding to the fixation position has already been acquired. That is, in the case of the display of only the fixation light display F, it is unknown whether it indicates the fixation position scheduled to be taken or the fixation position taken. Misidentification and misoperation can be avoided. The corneal thickness CT is displayed in addition to the thumbnail SN and the fixation lamp display F. The corneal thickness is a parameter different from the endothelial image and the analysis result, and the corneal thickness at each fixation position is displayed. This is because it is useful for checking whether it has already been acquired.

  As described above, photographing is performed until all necessary image photographing is completed. According to the display layout as described above, an observation image (for example, an anterior segment image) of the eye E and a plurality of imaging results regarding each fixation position are displayed on the same screen in a format divided into left and right eyes. . For this reason, even when acquiring endothelial images at a plurality of imaging positions, the examiner can smoothly perform fixation position setting, alignment work, and imaging work.

  FIG. 13A and FIG. 13B are diagrams illustrating an example of a photographing result screen. There are two types of shooting result screens: a single display (see FIG. 13A) for showing a single shooting result for each of the left and right eyes, and a multi-display (see FIG. 13B) for showing a plurality of shooting results for the left and right eyes. It is prepared.

<Single display>
On the single display screen, endothelial images 500R and 500L, photographing eye displays 502R and 502L, analysis values 504R and 504L, a delete button 506, a print button 508, and a photographing button 510 are displayed.

  The control unit 90 provides endothelium image display areas at the left and right ends of the area for displaying fixation position information and analysis results, displays the left eye endothelium image in one area, and the right eye endothelium image in the other area. Is displayed.

  On the single display screen, the imaging results of the left and right eyes (endothelium images 500R and 500L, imaging eye displays 502R and 502L, analysis values 504R and 504L) are divided and displayed on the left and right. That is, the right eye image (500R, 502R, 504R) is displayed on one of the left and right screens, and the left eye image (500L, 502L, 504L) is displayed on the other screen. The

  In the endothelial images 500R and 500L, the endothelial images for analysis selected on the image selection screen are displayed in the left and right eyes, respectively. The endothelial images 500R and 500L are displayed with the left and right photographing eye displays 502R and 502L interposed therebetween.

  The photographic eye displays 502R and 502L display photographic eye information (left and right eyes, fixation lamp lighting position) of the displayed endothelial image. The photographing eye displays 502R and 502L are displayed adjacent to each other. In the analysis values 504R and 504L, the analysis result of the displayed endothelial image is displayed.

  The breakdown of the analysis results is cell number NUM, endothelial cell density CD, average endothelial area AVG, standard deviation SD, coefficient of variation CV, maximum area MAX, minimum area MIN, hexagonal cell appearance rate HEX. Further, the corneal thickness CT measured at the same time as the endothelial image is displayed in the columns of analysis values 504R and 504L.

  When the delete button 506 is pressed, the shooting data is deleted. After deletion, the screen is automatically switched to the observation screen. When the print button 508 is pressed, the displayed endothelial image and analysis value are printed by a built-in printer (not shown). When the photographing button 510 is pressed, the screen is switched to the observation screen and new photographing is started.

  According to the single display described above, it is possible to easily confirm the imaging result of each time of the left and right eyes, and thus it is useful for quickly confirming the state of the inner skin of the left and right eyes. Here, a fixation lamp display corresponding to each endothelium image is attached, so that the imaging site of the endothelium can be easily grasped. Furthermore, the appropriateness of imaging can be grasped from the anterior segment image corresponding to the displayed endothelial image. Moreover, the analysis result based on the displayed endothelial image can be easily grasped by displaying the analysis value.

<Multi display>
In the multi-display, a plurality of endothelial images are displayed for each of the left and right eyes, and data for displaying analysis values is selected. Unless otherwise specified, the device configuration is the same as that of the single display.

  The control unit 90 displays the fixation position information of the endothelial image selected from the plurality of endothelial images and the analysis result based on the endothelial image for each of the left and right eyes in the center of the screen of the monitor 95, as well as the fixation position information and analysis. Endothelial image display areas are provided at the left and right ends of the resulting display area, a plurality of left eye endothelial images are displayed in one area, and a plurality of right eye endothelial images are displayed in the other area.

  In the multi-display screen, a plurality of endothelial images 500R and 500L are displayed on the left and right divided screens. Each endothelium image is displayed with a fixation lamp display (fixation position display) 501R and 501L corresponding thereto. In one screen, the number of endothelial images displayed for each eye is determined in advance (for example, 4). When the number of endothelial images with one eye exceeds a predetermined number (for example, four), when the page button 512 is pressed, the displayed image is switched to the next image.

  On the multi-display screen, the photographing eye displays 502R and 502L and the analysis values 504R and 504L are updated according to the selected endothelial image. Here, one image is selected for each of the left and right endothelial images on which the photographed eye display and analysis values are displayed, and data corresponding to the selected endothelial image is displayed on the photographed eye displays 502R and 502L and analysis values 504R and 504L. The The control unit 90 highlights and displays the selected image so that the selected image can be distinguished from other images (for example, color the figure number, surround the image with a frame, etc.).

  According to the multi-display, it is possible to easily confirm the imaging results of a plurality of times for each left and right eye, which is useful for quickly confirming the state of the left and right eye endothelium. Here, a fixation lamp display is attached to each of the plurality of endothelial images, so that the imaging regions corresponding to the plurality of endothelial images can be easily grasped. Furthermore, it is possible to grasp whether or not the selected endothelium image is photographed based on the anterior segment image corresponding to the selected endothelium image. Further, by displaying the analysis value corresponding to the selected endothelial image, the analysis result based on the selected endothelial image can be easily grasped.

  It should be noted that a mode is selected between the single mode and the multi mode as the parameter setting when displaying the photographing result screen. This is selected on a predetermined parameter setting screen.

  When the single mode is selected, the control unit 90 displays the shooting result screen in a single display (see FIG. 13A) regardless of the number of shootings. When each shooting is completed with the left and right eyes, the control unit 90 switches from the shooting screen to the shooting result screen with the completion as a trigger. Thereby, the examiner can smoothly check the imaging results of the left and right eyes. In the single mode, the number of times of shooting is one each for the left and right, and if the number of shots exceeds this, the previous image data is deleted and only the latest shooting data is displayed.

  When the multi mode is selected, the control unit 90 switches between the single display (FIG. 13A) and the multi display (FIG. 13B) according to the number of times of shooting. In the multi mode, when shooting is performed once with the left and right eyes, when the shooting result button 310 is pressed, the shooting result screen is displayed in a single display. On the other hand, in the case where shooting has been performed more than once with the left and right eyes, when the shooting result button 310 is pressed, the shooting result screen is displayed in multi-display. Thereby, since the display screen of the photographing result is changed according to the number of photographing, the examiner can easily confirm the photographing result.

  In the multi mode, the image data is stored in the memory 92 up to a predetermined number of times on each of the left and right sides (for example, 10 times). When the number of shots exceeds the upper limit, the oldest data is deleted in order. In the single mode, the number of times of shooting is one each for the left and right, and the previous image data is erased when repeated shooting is performed.

  The present invention is not limited to the embodiments described above, and many modifications are possible by those having ordinary knowledge in the art within the technical idea of the present invention.

It is an external appearance side block diagram of the corneal-endothelial-cells imaging device which concerns on this embodiment. It is a schematic block diagram which shows an example of the optical arrangement | positioning when the optical system accommodated in the imaging | photography part is seen from upper direction, and the structure of a control system. It is a figure when the 1st projection optical system and the 2nd projection optical system 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 imaging | photography of the endothelium of the cornea center part, and is a display example in case there exists a misalignment. It is a figure which shows an example of the anterior ocular segment observation screen at the time of imaging | photography of the endothelium of a cornea center part, and is the example of a display in the state with an appropriate alignment. It is a figure which shows an example of precise alignment detection. It is a figure which shows an example at the time of determining the light reception state of a cornea image based on the output image from an image pick-up element. It is a figure which shows the change of the light reception state of a cornea reflected light when an imaging | photography part is advanced, and is a figure when the alignment of a XYZ direction is completed. It is a figure which shows the change of the light reception state of the cornea reflected light when an imaging | photography part is advanced, and is a figure after epithelial reflected light is moved. It is a figure which shows the change of the light reception state of the cornea reflected light when an imaging | photography part is advanced, and is a figure when endothelium reflected light passes the predetermined detection area. It is a graph which represents the change of total value SLC1 when an imaging part is advanced in time series. It is a graph which represents the change of total value SLC2 when an imaging part is advanced in time series. It is a figure which shows an example of the measuring method of the corneal thickness which concerns on this embodiment. It is a figure which shows an example of the imaging | photography screen which concerns on this embodiment. It is a figure which shows an example of the fixation light screen which concerns on this embodiment. It is a figure which shows an example of the image selection screen which concerns on this embodiment. It is a figure which shows an example of the imaging | photography result screen (single display) which concerns on this embodiment. It is a figure which shows an example of the imaging | photography result screen (multi-display) which concerns on this embodiment.

4 Shooting unit (device main unit)
6 driving unit 10 illumination optical system 12 illumination light source 30 imaging optical system 60a, 60b first projection optical system 65a to 65d second projection optical system 80 anterior ocular segment observation optical system 85 Z alignment detection optical system 85a light projection optical system 85b light reception Optical system 90 Control unit 92 Memory 95 Monitor

Claims (4)

An illumination optical system that irradiates illumination light from an illumination light source obliquely toward the subject's cornea; and
An imaging optical system for receiving reflected light from the cornea containing corneal endothelial cells by an imaging device and acquiring an endothelial cell image of the cornea;
An internal fixation optical system comprising: a central fixation lamp; and a plurality of neighboring fixation lamps arranged on the same circumference around the central fixation lamp;
An external fixation optical system comprising a plurality of peripheral fixation lamps arranged on the same circumference around the central fixation lamp, and
The plurality of near fixation lamps are 0 degree (3 o'clock) , 45 degrees, 90 degrees (12 o'clock) , 135 degrees, 180 degrees (9 o'clock) , 225 degrees, 270 degrees (6 degrees ) as viewed from the subject. ) , Arranged at each predetermined position of 315 degrees, provided for acquiring an endothelial cell image in a region near the central portion of the cornea of the eye to be examined,
The plurality of peripheral fixation lamps are arranged at predetermined positions at 2 o'clock, 4 o'clock, 6 o'clock, 8 o'clock, 10 o'clock, and 12 o'clock as seen from the subject, and are located closer to the vicinity of the central portion of the cornea Furthermore, it is provided to acquire the outer endothelial cell image,
Each endothelial cell image acquired by the plurality of near fixation lamps arranged at 0, 45, 135, 180, 225, and 315 degrees is 2 o'clock, 4 o'clock, 8 o'clock, 10 o'clock, A corneal endothelial cell imaging apparatus, characterized in that an axial angle on the cornea is different for each endothelial cell image acquired by the plurality of peripheral fixation lamps arranged at the time position. The plurality of near fixation lamps are arranged at positions where the visual axis of the eye to be examined is inclined by 3 degrees to 10 degrees with respect to the central fixation lamp,
2. The corneal endothelium according to claim 1, wherein the plurality of peripheral fixation lamps are arranged at positions where the visual axis of the eye to be examined is inclined by 20 degrees to 35 degrees with respect to the central fixation lamp. Cell imaging device.   2. The corneal endothelial cell imaging device according to claim 1, wherein the plurality of near fixation lamps are arranged at positions where the visual axis of the eye to be examined is inclined by 5 degrees with respect to the central fixation lamp. .   Display for displaying on the touch panel monitor a setting screen for setting the lighting position of the fixation lamp arranged in the internal fixation optical system and the lighting position of the fixation lamp arranged in the external fixation optical system The corneal endothelial cell imaging apparatus according to claim 1 or 2, further comprising a control unit.

Images