JP2003000545A - Corneal cell photographing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corneal cell photographing device, by which respective corneal layers between the corneal endothelium and the corneal epithelium can easily be photographed and further a clear image less in distortion can be obtained. SOLUTION: This device is provided with an optical illuminating system 1 for irradiating an eye 10 to be examined with illuminating light from the obliquely front side, an optical photographing system 2 for photographing an image formed by the illuminating light reflected on an anterior ocular segment 10a of the eye 10, an optical alignment system 5 for controlling the alignment of the optical illuminating system 1 and the optical photographing system 2 on the XY plane, and an optical focusing system 6 for controlling the focus of the optical illuminating system 1 and the optical photographing system 2 in a Z-axis direction. An objective lens 3 turned to the anterior ocular segment 10a has a configuration separating an illuminating part 31 comprising the optical illuminating system 1 and a photographing part 32 comprising the optical photographing system 2 with a shielding part 33. Besides, a rotary disc 4 is provided while having a first slit 41 for making the illuminating light into slit and a second slit 42 for passing reflected light from the anterior ocular segment 10a of the eye 10 synchronously to the first slit 41. Further, a photographing position in the direction of the thickness of the cornea is controlled by controlling the optical focusing system 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corneal cell imaging apparatus, and more particularly to a corneal cell imaging apparatus in which one objective lens is divided into two and used as an illumination optical system and an imaging optical system. The present invention relates to a corneal cell imaging apparatus having a focusing function and capable of adjusting an imaging position in the corneal thickness direction.

[0002]

2. Description of the Related Art In recent years, a corneal cell imaging apparatus capable of imaging corneal endothelial cells without contacting an eye to be examined has been developed. With such a non-contact type device, it is possible to easily perform imaging of corneal cells without requiring skill. However, in recent years, not only corneal endothelial cells but also a corneal cell imaging apparatus capable of easily imaging each corneal layer such as a corneal stroma portion in a non-contact manner has been desired.

On the other hand, recently, LASIK (laser in situ kerato) for corneal refractive correction of myopia by surgical operation.
mileusis) is being held. In the LASIK operation, cells immediately below the corneal flap are excised by laser light, so that it is necessary to follow up the state of the operation site in the corneal stroma after the operation. Therefore, the corneal cell imaging apparatus is required to be able to image not only the corneal endothelium but also the corneal stroma between the endothelium and the epithelium.

[0004]

However, according to the conventional technique, a contact-type corneal cell imaging device must be used to image a corneal stroma, and a non-contact device can be used for corneal stroma. It was difficult to shoot the part. The reason is,
This is because the non-contact type cannot fix the positional relationship between the eye to be inspected and the device at the time of imaging, and since the layers other than the endothelium do not have significant layered tissue, the reflected light is weak and the target layer itself. Is difficult to detect. Furthermore, since the images of each layer of the corneal stroma are located between the reflected light of the corneal endothelium and the strongly scattered reflected light of the corneal surface, the separation in the corneal thickness direction is more than ever before to photograph this. Because it is required by.

The present invention has been made to solve the above problems, and an object of the present invention is to automatically and quickly take an image of an arbitrary position of the corneal parenchymal region between the endothelium and the epithelium of the cornea. (EN) It is possible to provide a corneal cell imaging apparatus capable of achieving a clear image with less distortion and good separation in the thickness direction of the cornea over a wide visual field.

[0006]

The corneal cell imaging apparatus of the present invention is a corneal cell imaging apparatus for imaging a predetermined position in the thickness direction of the cornea in the anterior segment of the eye to be inspected,
An illumination optical system for illuminating the anterior segment of the eye to be examined obliquely from the front with an illumination light from an illumination light source, and an imaging optical system for capturing an image in the anterior segment illuminated by the illumination light. And an objective unit having an illuminating section forming a part of the illuminating optical system, a photographing section forming a part of the photographic optical system, and a shielding section for separating the illuminating section from the photographic section. An alignment means for aligning the illumination optical system and the photographing optical system in an XY plane perpendicular to the optical axis (Z axis) of the eye to be inspected, and the optical axis (Z
A focusing means for focusing the illumination optical system and the photographing optical system in the (axis) direction, and mounting the illumination optical system, the photographing optical system, the objective lens, the alignment means, and the focusing means. XYZ mount and the X for the eye to be examined
A moving means for adjusting the position of the YZ mount, and the focusing means has a focusing light source and a focusing detection optical sensor,
The reflected light at the anterior segment of the index for detection by the focusing light source, by detecting with the optical sensor through the illumination unit and the imaging unit of the objective lens and the eye to be examined,
It is characterized in that the moving means is driven to adjust the position of the XYZ mount to focus the illumination optical system and the photographing optical system in the optical axis direction of the eye to be inspected.

As described above, by partitioning one objective lens with the shielding part, one of which is a part of the illumination optical system and the other is a part of the photographing optical system, an image photographed from the front of the eye to be examined can be obtained. An image of the parenchymal corneal region with little distortion can be obtained. Further, in the present invention, focusing is optically performed after the alignment of the illumination optical system and the photographing optical system by the alignment unit or in parallel with the alignment through the illumination unit and the photographing unit of the objective lens and the eye to be examined. Therefore, the accurate focusing of the illumination optical system and the photographing optical system can be performed quickly and automatically, and photographing can be performed at the target position of the eye to be inspected.

In addition to the above, in the corneal cell imaging apparatus of the present invention, the movable first slit for scanning the illumination light from the illumination light source in a slit shape and the reflection on the anterior segment of the eye. The imaging optical system further includes a slit scanning unit having a movable second slit that allows the photographing light generated by the irradiation of the slit-shaped illumination light to pass in synchronization with the first slit. By scanning the image by the slit-shaped photographing light passing through, it is possible to add a configuration for photographing an image at a predetermined position in the thickness direction of the cornea of the anterior segment of the eye to be examined over a predetermined region. it can.

As described above, the slit scanning means is provided, the illumination light is emitted through the first slit, and the photographing light is photographed through the second slit which is synchronized with the first slit. The effect of ambient light in the thickness direction can be eliminated to obtain an image in the anterior segment over a wide field of view, and an image with good separation in the corneal thickness direction can be obtained.

Here, in the above, the slit scanning means can be constituted by a rotating disk provided with the first slit and the second slit. By configuring the slit scanning means with a rotating disk, it is possible to easily perform the synchronous scanning of the slits.

By adjusting the position of the detection index by the focusing light source in the focusing means,
The XYZ mount may be moved to adjust the photographing position of the photographing optical system in the thickness direction of the cornea of the subject's eye. With such a configuration, an image can be obtained at any position in the thickness direction of the corneal stroma.

In the focusing means, the XYZ mount is moved by adjusting the detection position of the detection index light reflected by the anterior segment of the eye to be inspected and incident on the focusing sensor. It is also possible to adjust the photographing position of the photographing optical system in the thickness direction of the cornea of the subject's eye.
With such a configuration, an image can be obtained at any position in the thickness direction of the corneal stroma.

Further, in the above-mentioned structure in which the position of the detection index by the focusing light source can be adjusted, the position of the detection index by the focusing light source and the thickness of the cornea of the eye to be examined. To display the position in the thickness direction of the cornea of the part imaged in the imaging optical system based on the previously determined relationship with the imaging position of the imaging optical system in the direction. Can be configured. That is, as described above,
Since the photographing position of the photographing optical system in the corneal thickness direction is determined based on the position of the detection index by the focusing light source, the position of the detection index by the focusing light source and the corneal thickness direction are determined. If the relationship between the photographing position of the photographing optical system and the corneal endothelium, which has a clear layered structure and in which reflected light is easy to detect, is obtained in advance as a reference, the image obtained by the photographing optical system is It is possible to find at which position in the thickness direction of the obtained. Such positional information in the thickness direction of the cornea is very useful for ophthalmological treatment.

Further, in the above-mentioned configuration in which the detection position of the output index in the focusing sensor can be adjusted, the light is reflected by the anterior segment of the eye to be inspected and enters the focusing sensor. Based on a previously determined relationship between the detection position of the detection index light and the photographing position of the photographing optical system in the thickness direction of the cornea of the subject's eye, the photograph was taken by the photographing optical system. It can be configured to display the location of the site in the thickness direction of the cornea.

In the present invention, the alignment means has a first distance from the center of the objective lens in a direction and a direction perpendicular to the first direction toward the eye to be inspected. The two alignment light sources that emit the first detection light and the second detection light respectively, and the reflection of the first detection light and the reflection of the second detection light on the eye by moving the XYZ mount. For shooting light,
Alignment light imaging means provided on the eye side of the shielding portion of the objective lens, the reflected light of the first detection light imaged by the alignment light imaging means,
Alignment in the one direction is performed by detecting entry into a predetermined detection range in a direction orthogonal to the one direction, and the second detection light of the second detection light imaged by the alignment light imaging device is detected. It is possible to perform alignment in the other direction by detecting that the reflected light enters a predetermined detection range in a direction orthogonal to the other direction.

In such a configuration, since the alignment is detected in two orthogonal directions, it is possible to perform accurate alignment in the XY plane.

Further, in the above, the alignment light source that emits the first detection light and the alignment light source that emits the second detection light are alternately blinked to perform the alignment in the one direction and the other. Can be configured to perform alignment in the direction. In this way, by blinking the two alignment light sources, alignment in two directions can be performed at the same time, and quick alignment in the XY plane can be performed.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a planar configuration of a corneal cell imaging apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of only the optical system part of FIG. The corneal cell imaging apparatus of the present embodiment is an image of the illumination optical system 1 for irradiating the anterior segment 10a of the subject's eye 10 with illumination light obliquely from the front, and an image of the portion of the anterior segment 10a illuminated with the illumination light. A photographing optical system 2 for photographing a subject and an optical axis 10b (Z
An optical axis 10b (Z) of the eye 10 to be inspected, and an alignment optical system 5 for controlling alignment (positioning) of the illumination optical system 1 and the photographing optical system 2 in an XY plane perpendicular to the (axis).
A focusing optical system 6 for controlling focusing (imaging position adjustment) of the illumination optical system 1 and the photographing optical system 2 in the axial direction. The illumination optical system 1, the photographing optical system 2, the alignment optical system 5, and the focusing optical system 6 all have a fixed focus.

Further, the corneal cell imaging apparatus of this embodiment is
An objective lens 3 directed to the anterior segment 10a is provided, and the objective lens 3 includes an illuminating section 31 that constitutes the illuminating optical system 1 and a photographing section 32 that constitutes the photographic optical system 2, as described later.
And a shielding unit 33 for separating the illumination unit 31 and the photographing unit 32. As shown in FIG. 1, the shields 33 are provided on both sides of the subject's eye 10 side and its back side. Furthermore, the corneal cell imaging apparatus of the present embodiment includes a rotating disc 4, and the rotating disc 4 has a first slit 41 for making illumination light into a slit shape, as shown in FIG.
The second slit 42 that allows the imaging light from the anterior ocular segment 10 a of the subject eye 10 to pass therethrough in synchronization with the first slit 41. Further, the rotary disc 4 is rotated in the direction shown by the arrow 4a (FIG. 2) by the drive of the drive motor 43.
2 and 5, only three or four first slits 41 and two second slits 42 are drawn for simplification, but in reality, the first slit 41 and the second slit 42 are formed on the entire circumference of the rotary disc 4. 60 slits are formed at equal intervals over each slit (first slit 41 and second slit 4
The width of 2) is set to 100 μm, and the rotating disk 4 is 400
It is rotating at 0 rpm. It should be noted that the numbers and widths and intervals of the first and second slits and the number of rotations of the rotary disc 4 are not particularly limited to the above, and the illumination optical system 1
It suffices that the slit and the slit of the photographing optical system 2 have an optically equivalent relationship. And it is preferable that both slits have the same shape. Also, the smaller the width of the slit, the better the separation in the thickness direction of the cornea, but the darker the image obtained.

In this embodiment, the illumination optical system 1, the photographing optical system 2, the alignment optical system 5, the focusing optical system 6, the objective lens 3 and the rotating disc 4 are XY which are schematically shown by broken lines in FIG.
It is mounted on the Z mount 7. As will be described later, the XYZ mount 7 performs alignment on the XY plane of the apparatus of the present embodiment under the control of the control circuit 8 based on a signal from the alignment optical system 5, and also the focusing optical system 6 Focusing in the Z-axis direction is performed under the control of the control circuit 8 based on the signal from the.

In the present embodiment, as shown in FIGS. 1 and 2, the illumination optical system 1 includes a strobe discharge tube 11 that emits illumination light based on a signal from the strobe circuit 11a, and an illumination field stop 17 for the illumination light. The illumination lens 12 for condensing the light into the first slit 41 of the rotating disk 4 via the illumination lens 12 and the illumination projection lens 13 for converting the illumination light slitted by the first slit 41 into parallel light (afocal). A first illumination light reflection mirror 14 and a second illumination light reflection mirror 15 for rotating the horizontal slit-shaped illumination light by 90 ° to make vertical slit-shaped illumination light, and the second illumination. A third illumination light reflection mirror 16 that causes the vertical slit illumination light reflected by the light reflection mirror 15 to enter the illumination unit 31 of the objective lens 3, and a slit illumination from the third illumination light reflection mirror 16. It is formed by the illumination part 31 of the objective lens 3 to be incident on the anterior segment 10a of the eye 10. The second illumination light reflection mirror 15 is composed of an infrared transmission mirror that reflects visible light and transmits infrared light in order to transmit infrared light used in a focusing optical system 6 described later. .

Further, in this embodiment, the photographing optical system 2 is
As shown in FIGS. 1 and 2, a photographing unit 32 of the objective lens 3 that captures an image by irradiation of the illumination light from the illumination optical system 1 to form parallel light (afocal), and photographing light from the photographing unit 32. Of the third photographing light reflecting mirror 26 for afocal reflection of light and a second for rotating the photographing light from the third photographing light reflecting mirror 26 by 90 degrees to obtain horizontal photographing light.
Photographing light reflection mirror 25 and first photographing light reflection mirror 2
4, and an imaging lens 23 for imaging for focusing afocal imaging light on the second slit 42 of the rotating disk 4,
A photographing lens 22 and a photographing CCD camera 21 for photographing the image after passing through the second slit 42 through the field stop 27.
It is composed of and. Second photographing light reflection mirror 2
Reference numeral 5 reflects visible light and transmits infrared light in order to transmit infrared light used in a focusing optical system 6 described later in the same manner as the second illumination light reflecting mirror 15 described above. It is composed of an infrared transmission mirror.

The corneal cell imaging apparatus of this embodiment further includes
It has an illumination optical system 1 in an XY plane perpendicular to the optical axis 10b (Z axis) of the subject's eye 10 and an alignment optical system 5 for performing alignment of the photographing optical system 2. Since the alignment optical system 5 is located above the plane of the drawing in FIG. 1, it is shown by a dashed line. Alignment optical system 5
As shown in FIG. 2, the alignment operation is performed so that the intersection of the optical axis 1b of the illumination optical system 1 and the optical axis 2b of the photographing optical system 2 is located on the optical axis 10b of the eye to be inspected.

FIG. 3 shows the arrangement in the vicinity of the objective lens 3 as seen from the eye 10 to be examined. As shown in FIG. 3, the alignment optical system 5 is provided on the lower side in the vertical (Y-axis) direction of the objective lens 3 and on the right side in the horizontal (X-axis) direction of the objective lens 3. The light source 51 for Y-axis alignment is provided. Both the X-axis alignment light source 52 and the Y-axis alignment light source 51 are infrared LEs.
D, which is configured to emit infrared detection light toward the subject's eye 10. In addition, the alignment optical system 5
It has a SELFOC (trademark) 53 that collects the detection light emitted from the X-axis alignment light source 52 and the Y-axis alignment light source 51 and reflected by the subject's eye 10. The SELFOC 53 has a function of forming an image of the light incident on the opening 53a at a position at a predetermined distance from the opposite end. Therefore, as shown in FIG.
The light emitted from the above is guided upward along the optical axis 5b, further reflected by the reflection mirror 54, and imaged on the CCD camera 55 by the imaging lens 58. The image signal from the CCD camera 55 is sent to the monitor 9 via the control circuit 8.
Is displayed in.

The alignment operation in the X-axis direction in the alignment optical system 5 will be described. Figure 4 (a)
The screen by the CCD camera 55 displayed on the monitor 9 when performing the alignment in the X-axis direction is shown. When the alignment is not established, the spot 5X of the infrared detection light from the X-axis alignment light source 52 (FIG. 3) is displayed on the screen of the monitor 9 at a position on the screen of the monitor 9 shown in FIG. It is projected. Note that FIG.
The position of the anterior segment 10a shown by a broken line in (a) is after the establishment of the alignment, and the anterior segment 10a is not at this position when the alignment is not established. Next, the control circuit 8
Moves the XYZ mount 7 until the spot 5X moves in the direction indicated by the arrow 5c and reaches the detection range 56 at the center position of the screen of the monitor 9 (5X 'in FIG. 4A). When the spot 5X enters the detection range 56, the anterior segment 10a appears at the position shown by the broken line in FIG. 4A, and the alignment in the X-axis direction is completed.

Next, the operation of alignment in the Y-axis direction in the alignment optical system 5 will be described. Figure 4
(B) shows a screen by the CCD camera 55 displayed on the monitor 9 when performing alignment in the Y-axis direction. When the alignment is not established, the Y-axis alignment light source 51 is displayed on the screen of the monitor 9.
The spot 5Y of the infrared detection light from (FIG. 3) is displayed at a position on the screen of the monitor 9 shown in FIG. 3, for example. As in the case of FIG. 4A, the position of the anterior segment 10a indicated by the broken line in FIG.
When the alignment is not established, the anterior segment 10a
Is not in this position. Next, the control circuit 8 turns the spot 5
Until Y reaches the detection range 57 at the center position of the screen of the monitor 9 by moving in the direction indicated by the arrow 5d (5 in FIG. 4B).
Y ′), XYZ frame 7 is moved. When the spot 5Y enters the detection range 57, the anterior segment 10a appears at the position shown by the broken line in FIG. 4B, and the alignment in the Y-axis direction is completed.

At the time of performing alignment in the X-axis and Y-axis directions, focusing in the Z-axis direction has not yet been performed, and the X-axis alignment light source 52 and the Y-axis alignment light source 51 are not provided. Since it is not located at the center of the objective lens 3, on the screens shown in FIGS. 4A and 4B, the spots 5X and 5Y are not always located at the center of the anterior segment 10a even when the alignment is completed. Not located

Although the X-axis and Y-axis alignments have been separately described above, the X-axis alignment light source 52 is actually used in the corneal cell imaging apparatus of this embodiment.
And the Y-axis alignment light source 51 is alternately blinked in synchronism with the vertical synchronization of the camera 55 to alternately perform alignment in the X-axis and Y-axis directions, and substantially perform alignment in the X-axis and Y-axis directions at the same time. ing. The reason why such alignment can be executed simultaneously is that the operation of the XYZ gantry 7 is much slower than the operation of detecting alignment in the X-axis and Y-axis directions shown in FIGS. 4A and 4B.

In addition, for convenience of description, FIG.
Although the description has been given along the screen of the monitor 9 shown in (a) and (b), it is not actually necessary to display it on the monitor screen, and the alignment process can be completed within the control circuit 8.

In the corneal cell imaging apparatus of the present invention, the focusing optical system 6 is, as shown in FIGS. 1 and 2, an infrared LED 61 which is a light source for focusing and an infrared light from the infrared LED 61. A condenser lens 62 for condensing the infrared light, a movable slit 63 that makes the infrared light into a slit shape, a lens 65 that makes the infrared light from the movable slit 63 parallel light, and the positions of the movable slit 63 are adjusted. Motor 64 and encoder 64a
And have. In this specification, the movable slit 63 itself or a slit-shaped image formed by the movable slit 63 is referred to as a detection index. The motor 64 uses the anterior segment 1 as described later.
In order to adjust the photographing position in the thickness direction of the cornea of 0a, the position of the movable slit 63 is adjusted by the signal given from the encoder 64a. The detection index coming out of the lens 65 is the second illuminating light reflecting mirror 15, which is infrared transparent,
It is projected onto the anterior segment 10 a of the subject's eye 10 via the third illumination light reflection mirror 16 and the illumination section 31 of the objective lens 3.
The second illumination light reflection mirror 15, the third illumination light reflection mirror 16, and the illumination section 31 of the objective lens 3 also constitute the focusing optical system 6. If focus is established, eye 1
The index light for detection reflected by the anterior segment 10a of 0 is collimated by the photographing unit 32 of the objective lens 3, and the third photographing light reflecting mirror 26 and the infrared transmitting second photographing light reflecting mirror 26 are provided. The light reaches the optical sensor 67 for focus detection through 25 and the condenser lens 66. Imaging unit 3 of the objective lens 3
2, a third photographing light reflecting mirror 26, an infrared transmitting second photographing light reflecting mirror 25, a condenser lens 66 and an optical sensor 6.
7 also constitutes the focusing optical system 6.

In the present embodiment, for focusing in the Z-axis direction, after the alignment in the XY plane is completed, the XYZ gantry 7 is advanced toward the subject's eye 10 and detected by the anterior segment 10a. This is achieved by detecting a predetermined portion of the target index light by the optical sensor 67. That is, the index light for detection is not detected by the optical sensor 67 at a position sufficiently distant from the eye 10 to be inspected, and when the XYZ gantry 7 is advanced from this position in the direction of the eye 10 to be inspected, the objective lens 3 gradually moves to the eye to be inspected. 10, the index for detection enters the anterior segment 10a, and the index light reflected from each part of the anterior segment 10a reaches the imaging unit 32 of the objective lens 3. The index light due to this reflection has a pattern similar to that shown in FIG.
It is possible to determine that focusing is achieved by detecting the reflection portion from the corneal endothelium of the detection index light pattern at 7, for example. In this embodiment, since the focus of the photographing optical system 2 is fixed as described above, the XYZ mount 7
Focusing is performed by adjusting the position of. In the above description, focusing is performed after completion of alignment in the XY plane. However, alignment and focusing in the XY plane can be performed at the same time.

Next, the anterior ocular segment 10a by the illumination optical system 1 and the photographing optical system 2 after the alignment and the focus are established.
The operation of capturing an image at a predetermined position in the thickness direction of the cornea will be described. When focus is detected by the focus optical system 6 as described above, the illumination light is emitted by the stroboscopic light emission of the strobe discharge tube 11, and the illumination light is emitted from the rotating disc 4 that rotates via the illumination lens 12. The first slit 41 forms a horizontal slit shape. This slit-shaped illumination light is converted into parallel light by the illumination projection lens 13,
The first illumination light reflection mirror 14 and the second illumination light reflection mirror 15 provide slit-shaped illumination light in the vertical direction (Y-axis direction). This illumination light is reflected by the third illumination light reflection mirror 16
Also, the anterior segment 10a of the subject's eye 10 is irradiated obliquely from the front via the illumination section 31 of the objective lens 3 and an image is formed at a predetermined photographing position in the thickness direction of the cornea.

FIG. 6 schematically shows a cross section of the cornea of the anterior segment 10a of the subject's eye 10. As shown in FIG.
The cornea is composed of corneal epithelial cells 71 on the surface and corneal endothelial cells 73.
And the corneal stroma 72 exists between them. Further, a tear film 74 exists outside the corneal epithelial cells 71. The above-mentioned slit-shaped illumination light 70 projected on the anterior segment 10a is imaged at an intersection point 75a between the optical axis 1b of the illumination optical system 1 and the optical axis 2b of the photographing optical system 2, and further to the corneal endothelial cells 73. Will be reached. Such illumination light 7
By irradiation of 0, reflected light in the range shown by the arrow 80 is obtained from the entire cornea. FIG. 7 shows the amount of reflected light at each part of the cornea. As shown in FIGS. 6 and 7,
The reflected light from the cornea includes the tear light layer 74 in addition to the photographing light 77 from the photographing portion 75 to be photographed of the corneal stroma.
There is a very strong reflected light 76 from the cornea and a reflected light 78 from the corneal endothelial cells 73 stronger than the photographing light 77. The reflected light including the photographing light 77 and the reflected lights 76 and 78 is captured by the photographing unit 32 (FIGS. 1 and 2) of the objective lens 3. Then, the reflected light captured by the imaging unit 32 maintains the afocal state, and the third imaging light reflection mirror 26 and the second imaging light reflection mirror 2
5 and the first photographing light reflecting mirror 24 to change the direction of the image in the horizontal direction, and the photographing imaging lens 2
It is projected onto the second slit 42 of the rotating disc 4 via the lens 3. At that time, only the portion of the reflected light, which is the photographing light 77, passes through the second slit 42 and is imaged by the photographing CCD camera 21 via the field stop 27 and the photographing lens 22. In this way, the second slit 42
By photographing only the portion of the photographing light 77 via the, the reflected lights 76 and 78 stronger than the photographing light 77 can be cut and the image of the portion of the corneal substantial portion 72 desired to be photographed can be captured clearly. Further, as described later, by scanning the first slit 41 and the second slit 42 of the rotary disc 4, the imaging portion 7 is moved in the direction shown by the arrow 79 in FIG.
5 is scanned, and an image of the corneal stroma with a wide field of view corresponding to the field stop 27 is obtained. In the present embodiment, the first slit 41 and the second slit 41 of the rotating disc 4 are
By adjusting the width of the slit 42 of the
The width of the photographing light 77 that reaches the D camera 21 can be adjusted. The smaller the width, the better the separation in the thickness direction of the cornea, but the darker the image obtained.

The position in the thickness direction of the cornea of the photographing portion 75 photographed by the photographing CCD camera 21 is as follows by adjusting the position of the movable slit 63 in the focusing optical system 6. It can be adjusted. First,
A case will be described where the corneal endothelium is used as a reference for detecting focus and the corneal endothelium is imaged. In this case, since both the focus detection reference and the imaging site are the corneal endothelium, focus detection and imaging are performed with the optical axis of the focusing optical system 6 and the optical axis of the illumination optical system 1 aligned. Be seen. That is, as the detection index light reflected by the corneal endothelium is detected by the optical sensor 67 due to the advance of the XYZ mount 7 in the direction of the eye 10 to be inspected, the focus is detected, and at this time, the optical axis of the illumination optical system 1 is detected. The photographing position of the intersection of 1b and the optical axis 2b of the photographing optical system 2 is also located on the corneal endothelium. In this state, the stroboscopic discharge tube 11 emits light and the photographing CCD camera 21 photographs the corneal endothelium. Become.

Next, the case of photographing the corneal stroma will be described. Imaging of the corneal stroma is performed by moving the position of the movable slit 63 to the left side (the direction away from the motor 64) in FIG. Also in this case, focus detection is performed with the corneal endothelium as a reference as in the above. When the movable slit 63 is moved to the left side in FIG. 1, the projection position of the detection index, after passing through the third illumination light reflecting mirror 16 and the illumination unit 31 of the objective lens 3, is the above-mentioned imaging of the corneal endothelium. 1 will be moved to the upper side of FIG.
Since the optical axis 2b of the photographing optical system 2 and the optical axis of the focusing optical system 6 on the side of the photographing unit 32 always coincide with each other, the detection index detection position is illuminated by the upward movement of the detection index projection position. The optical axis 1b of the optical system 1 and the optical axis 2b of the imaging optical system 2 are located on the far side (left side in FIG. 1) of the eye 10 from the photographing position. Therefore, such a movable slit 6
At the position 3, the optical sensor 67 is moved when the XYZ gantry 7 is advanced toward the subject's eye 10 (from the right side to the left side in FIG. 1).
Then, the detection index light reflected from the corneal endothelium is detected earlier than in the case of imaging the corneal endothelium, and the focus is established earlier than in the case of corneal endothelium imaging. In other words, the focus is established before the XYZ gantry 7 approaches the photographing position of the corneal endothelium. At the time when this focus is established, the photographing position of the intersection of the optical axis of the illumination optical system 1 and the optical axis of the photographing optical system 2 has not reached the corneal endothelium yet, so the stroboscopic discharge tube 11 emits light at this point. Then, the photographing CCD camera 21 photographs the corneal stroma located on the right side in FIGS. 6 and 1 with respect to the corneal endothelium.

In the corneal cell imaging apparatus of this embodiment, the relationship between the position of the movable slit 63 and the imaging position in the corneal thickness direction is previously determined with reference to the light reflected from the corneal endothelium. The position of the movable slit 63 is determined according to the required imaging position in the corneal thickness direction, and the movable slit 63 is moved to that position from the encoder 64a via the motor 64. Then, the position in the thickness direction of the cornea of the photographed image corresponding to the position of the movable slit 63 is superimposed and displayed, for example, in the lower part of the image displayed on the monitor 9.

In this embodiment, the light source side (infrared LED
Although the movable slit is provided in 61), the slit on the light source side is fixed and the detection position of the optical sensor 67 is electrically changed, or even if the movable slit is provided on the optical sensor 67 side, the thickness of the cornea is the same. It is possible to change the shooting position in the vertical direction. In addition, the infrared LED 61 and the movable slit 63 are provided on the photographing optical system 2 side, and the optical sensor 6 is provided on the illumination optical system 1 side.
When 7 is provided, focusing can be performed similarly.

Imaging of the anterior segment 10a is performed while scanning the slits 41 and 42. As shown in FIG. 1, while the stroboscopic discharge tube 11 is emitting light, the rotation of the rotary disc 4 causes the first slit 41 to direct the illumination light from the illumination lens 12 from the front side to the back side of the paper surface of FIG. It will cross multiple times. The slit-shaped illumination light scanned from the front side to the back side of the paper surface is reflected by the mirrors 14, 15 and 1
The slit light in the Y-axis direction is made by 6 and the objective lens 3
An image is formed at a predetermined photographing position in the thickness direction of the cornea via the illumination unit 31 of. In the anterior segment 10a, this irradiation light is
Scanning is performed from the right side to the left side (from the lower side to the upper side of FIG. 1) toward the eye 10 on the paper surface of FIG. Next, the slit-shaped illumination light scanned in this manner is captured by the image capturing unit 32 of the objective lens 3 and formed into horizontal slits by the mirrors 26, 25, and 24, and passes through the image forming lens 23 for image capturing. When it reaches the rotating disk 4, it is the photographic light that is scanned from the back side to the front side of the paper surface of FIG. On the photographic optical system 2 side of the rotary disc 4, the first slit 41 on the illumination optical system 1 side and the second slit 42 on the opposite side with respect to the center of rotation are the first slit 41 and the first slit 41.
Since it moves from the back side to the front side of the paper surface of FIG. 1 in synchronization with the slit 41 of FIG. 1, the photographing light scanned from the back side to the front side maintains a position fixed relative to the second slit 42. It will be moved while standing. Therefore, even if the slit-shaped irradiation light is scanned and moved, as shown by the arrow 79 in FIG. 6, an image can always be obtained by the photographing CCD camera 21 at the same position in the thickness direction of the cornea. It will be.

FIG. 8 shows a state in which the slit-shaped photographic light after passing through the second slit 42 is viewed from the photographic CCD camera 21 through the field stop 27. The field stop 27 is provided with a window portion 27a having a length of 0.65 mm and a width of 0.5 mm, and a plurality of slit-shaped photographing light rays 29 pass through the window portion 27a from bottom to top as indicated by an arrow 28. To do. The light emitted from the strobe discharge tube 11 is a CCD camera 2 for photographing.
Since the scanning is performed in synchronization with the vertical synchronizing signal of 1, and the scanning of the slits 41 and 42 is performed a plurality of times during this stroboscopic light emission period, the CCD camera 21 for photographing has a plurality of scanning images. The signal will be accumulated. Next, the image corresponding to the window portion 27a accumulated in the photographing CCD camera 21 is transferred to the image memory 20. Next, the image in the image memory 20 is displayed on the monitor 9 via the control circuit 8. In addition, although the case where the slit scan is performed a plurality of times for one strobe emission has been described above, the present invention can also be applied to the case where one slit scan is performed for one strobe emission. When performing a slit scan once for each strobe emission, if a sufficient amount of illumination light can be secured, a clearer image than the one obtained by superimposing images by a plurality of slit scans as in the present embodiment. Has the advantage that

Although the corneal cell imaging apparatus for performing slit scanning with the slits provided on the rotating disc 4 has been described above, the present invention is also applicable to a normal corneal cell imaging apparatus without the rotating disc 4 and slits. You can

[0041]

As described above, in the corneal cell imaging apparatus of the present invention, the shielding section is provided between the illumination section which constitutes a part of the illumination optical system and the imaging section which constitutes a part of the imaging optical system. By using the objective lens separated by, the image of the cornea with less distortion similar to the image taken from the front of the subject's eye can be obtained. Further, in the present invention, since focusing is optically performed through the illumination unit and the photographing unit of the objective lens and the eye to be inspected, accurate focusing of the illumination optical system and the photographing optical system can be performed. It is possible to image the corneal stroma at a position in the thickness direction of the cornea over a wide field of view.

Further, since the position of the detection index by the focusing light source or the detection position of the detection index light can be adjusted, the imaging position in the thickness direction of the cornea by the imaging optical system is adjusted. be able to.

Further, in the present invention, the alignment means emits two detection lights toward the eye to be inspected from positions separated by a predetermined distance in two directions at right angles from the center of the objective lens, and the reflected lights thereof. Is detected, it is possible to perform accurate alignment in the XY plane.

Further, by disposing the alignment means in the shielding portion which separates the objective lens into the illuminating section and the photographing section, the illumination optical system and the photographing optical system are not disturbed.
Accurate alignment can be performed automatically.

In addition, in the corneal cell imaging apparatus of the present invention,
By providing a slit scanning means and irradiating the illumination light through the first slit and photographing the reflected light through the second slit synchronized with the first slit, the eyeball surface, epithelium, endothelium, etc. It is possible to capture the desired position in the thickness direction of the cornea by eliminating the influence of the strongly reflected light from.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a planar configuration of a corneal cell imaging apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of only a portion of the optical system of FIG.

FIG. 3 shows an arrangement in the vicinity of an objective lens viewed from an eye to be inspected.

FIG. 4A is a plan view showing a screen by a CCD camera displayed on a monitor when alignment is performed in the X-axis direction, and FIG. 4B is a case where alignment is performed in the Y-axis direction. 3 is a plan view showing a screen of a CCD camera displayed on the monitor of FIG.

FIG. 5 is a rotary disc 4 having a first slit for making the illumination light into a slit shape and a second slit for allowing the reflected light from the anterior segment of the subject eye to pass in synchronization with the first slit.
FIG.

FIG. 6 is a cross-sectional view schematically showing the cornea of the anterior segment of the eye.

FIG. 7 is a diagram showing a light amount distribution of reflected light in a thickness direction of a cornea.

FIG. 8 is a plan view showing how the slit-shaped photographing light after passing through the first slit is viewed from a photographing CCD camera through a field stop.

[Explanation of symbols]

1 Illumination optical system 2 Shooting optical system 3 Objective lens 4 rotating disks 5 Alignment optical system 6 Focusing optical system 7 XYZ stand 8 control circuit 9 monitors 10 eye 10a anterior segment 10b Optical axis of eye to be examined 11 Strobe discharge tube 11a Strobe circuit 21 CCD camera for shooting 27 Field stop 31 Lighting Unit 32 Imaging Department 33 Shield 41 First slit 42 Second slit 51 X-axis alignment light source 52 Y-axis alignment light source 53a opening 54 Reflective mirror 55 CCD camera 5X spot 5Y spot 56 detection range 57 Detection range 61 Infrared LED 63 movable slits 64 motor 64a encoder 67 Optical sensor 71 corneal epithelial cells 72 Corneal stroma 73 Corneal endothelial cells 74 tear film 77 Shooting light

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme coat (reference) G02B 7/11 DF term (reference) 2F065 AA01 BB07 BB22 CC16 FF10 GG07 GG08 GG21 HH03 HH05 JJ03 JJ26 LL04 LL10 LL12 LL20 LL50 LL30 LL50 LL30 PP04 SS02 SS03 SS13 2H051 BA70 CB05 CB11 CB29 CC08

Claims (9)

[Claims] 1. A corneal cell imaging device for imaging a predetermined position in the thickness direction of a cornea in an anterior segment of an eye to be inspected, the anterior eye of the eye to be inspected by illumination light from an illumination light source. Optical system for irradiating the front part of the eye obliquely, a photographing optical system for taking an image of the anterior segment illuminated by the illumination light, and an illumination forming a part of the illumination optical system. Section, an image pickup section forming a part of the image pickup optical system, and an objective lens having a shielding section for separating the illumination section and the image pickup section, and an optical axis perpendicular to the optical axis (Z axis) of the eye to be examined. An alignment means for aligning the illumination optical system and the photographing optical system in the XY plane, and focusing of the illumination optical system and the photographing optical system in the optical axis (Z-axis) direction of the eye to be examined. Focusing means for performing, the illumination optical system, the photographing optical system, the pair XYZ on which the object lens, the alignment means, and the focusing means are mounted
A gantry and a moving unit that adjusts the position of the XYZ gantry with respect to the eye to be inspected, and the focusing unit has a focusing light source and an optical sensor for focusing detection. The reflected light at the anterior segment of the index is detected by the optical sensor through the illumination unit and the imaging unit of the objective lens and the eye to be inspected, thereby driving the moving unit and the position of the XYZ mount. A corneal cell imaging apparatus for adjusting the illumination optical system and the imaging optical system in the direction of the optical axis of the eye to be inspected. 2. A movable first slit for scanning the illumination light from the illumination light source in a slit shape, and photographing light by irradiation of the slit illumination light reflected by the anterior segment of the eye. Slit scanning means having a movable second slit that is passed in synchronization with the slit, and the photographing optical system scans an image by the slit-shaped photographing light passing through the second slit. Due to
The corneal cell imaging apparatus according to claim 1, wherein an image of a predetermined position in the thickness direction of the cornea of the anterior segment of the eye to be inspected is taken over a predetermined region. 3. The slit scanning means comprises the first
The corneal cell imaging apparatus according to claim 2, wherein the corneal cell imaging apparatus is configured by a rotating disk provided with the slit and the second slit. 4. The XYZ mount is moved by adjusting the position of the detection index by the focusing light source in the focusing means to move the XYZ mount in the thickness direction of the cornea of the eye to be examined. The corneal cell imaging apparatus according to claim 1, wherein the imaging position of the imaging optical system is adjusted. 5. The XYZ mount is moved by adjusting the detection position of the detection index light reflected by the anterior segment of the eye to be inspected in the focusing means and incident on the focusing sensor. The corneal cell imaging apparatus according to claim 1, wherein the imaging position of the imaging optical system in the thickness direction of the cornea of the subject's eye is adjusted. 6. Based on a previously determined relationship between the position of the detection index by the focusing light source and the imaging position of the imaging optical system in the thickness direction of the cornea of the subject's eye,
The corneal cell imaging apparatus according to claim 4, wherein a position in the thickness direction of the cornea of the part imaged by the imaging optical system is displayed. 7. A detection position of detection index light reflected by the anterior segment of the eye to be inspected and incident on the focusing sensor, and an image of the imaging optical system in the thickness direction of the cornea of the eye to be inspected. The corneal cell imaging device according to claim 5, wherein the position in the thickness direction of the cornea of the part imaged by the imaging optical system is displayed based on a previously obtained relationship with the position. 8. The alignment means includes a first detection light beam toward a subject's eye from a position distant from the center of the objective lens by a predetermined distance in one direction and another direction perpendicular to the one direction. The two alignment light sources each of which emits the second detection light, and the movement of the XYZ pedestal cause the first of the first light in the eye to be examined.
Alignment light photographing means provided on the eye to be examined side of the shielding part of the objective lens for photographing the reflected light of the detection light and the reflected light of the second detection light. The first taken by
The reflected light of the detection light of No. 1 performs alignment in the one direction by detecting that it has entered a predetermined detection range in the direction orthogonal to the one direction, and is photographed by the alignment light photographing means. Said second
9. The alignment in the other direction is performed by detecting that the reflected light of the detection light of 1 has entered a predetermined detection range in a direction orthogonal to the other direction. Corneal cell imaging device. 9. The alignment light source that emits the first detection light and the alignment light source that emits the second detection light are blinked alternately to perform alignment in the one direction and alignment in the other direction. The corneal cell imaging apparatus according to claim 8, which is performed.