JP3264990B2 - Corneal endothelial cell imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corneal endothelial cell observation and photographing apparatus for illuminating a cornea of a subject's eye with illumination light to observe and photograph a corneal endothelial cell image of the subject's eye.

[0002]

2. Description of the Related Art Conventionally, as a corneal endothelial cell observing and photographing apparatus for observing and photographing a corneal endothelial cell image of an eye to be examined, a subject (patient) is anesthetized with eye drops, and then a cone is formed on the corneal surface of the eye to be examined. A contact type is known in which a lens is brought into contact to observe and photograph a corneal endothelium image. In this contact type,
There is a problem of damaging the corneal surface. In addition, it takes time to disinfect the cone lens. Therefore, a non-contact type in which an optical attachment for corneal endothelium observation is attached to a slit lamp to observe and photograph a corneal endothelial cell image has been developed.

In this non-contact type corneal endothelial cell observation and imaging apparatus, the relative positional relationship between the eye to be examined and the apparatus optical system (the position of the apparatus body in the vertical and horizontal directions with respect to the eye to be examined, the optical axis direction of the apparatus body with respect to the eye to be examined) Is adjusted by eye measurement, and the illumination light from the illumination light source for observation is directed obliquely toward the cornea, and the corneal endothelial cells are focused through the eyepiece based on the reflected light flux from the cornea. What is known is. It is also known that a subject focuses while viewing the corneal endothelial cells displayed on a monitor.

[0004]

By the way, the thickness of the cornea is thin and it is necessary to observe the corneal endothelial cells at a high magnification in order to observe them. Further, although the eye to be examined constantly performs fixation micromotion, the corneal endothelial cell image is largely shaken by the fixation micromotion because the magnification is high. Therefore, the non-contact type requires considerable skill to observe and photograph corneal endothelial cells.

That is, in the alignment operation of the apparatus main body with respect to the cornea in the vertical and horizontal directions, and the alignment operation of setting the distance of the apparatus main body with respect to the cornea,
Observe the corneal endothelial cell image itself or a dark state where nothing can be seen until the reflected luminous flux from the corneal surface that appears next to the image of the corneal endothelium has not been determined, as the appropriate positional relationship between the subject's eye and the device optical system has not been determined. Depends very much on the examiner's intuition and experience. In addition, since alignment often takes time, the subject is forced to keep his eyes open for a long time until the subject is focused and the imaging is completed.
The pain given to the subject is great.

The present invention has been made in view of the above circumstances, and an object of the present invention is to observe and photograph corneal endothelial cells capable of speeding up the alignment operation of the apparatus body with respect to the cornea without any skill. It is intended to provide a device.

[0007] Corneal endothelium imaging apparatus according to claim 1 of the present invention, in order to solve the above problems, an illumination optical system for irradiating an oblique toward the slit beam into the cornea of the eye, the corneal endothelial cells Optical system for receiving the reflected light from the device and taking an image of the device.
An alignment optical system for performing alignment, and performing an alignment operation in the optical axis direction of the apparatus body with respect to the eye to be inspected based on a reflection image of the slit light beam from the corneal surface .

[0008]

According to the corneal endothelial cell observation and photographing apparatus according to the present invention, an anterior ocular segment image can be observed by the anterior ocular segment optical system, and at this time, the illumination light flux reflected from the anterior ocular segment is reflected. The approximate positional relationship between the apparatus main body and the eye to be inspected can be known based on the image.

[0009]

Next, an embodiment of a corneal endothelial cell observation and photographing apparatus according to the present invention will be described with reference to FIGS.

FIG. 1 is a plan view showing a device optical system of a corneal endothelial cell observation and photographing apparatus. In FIG. 1, reference numeral 1 denotes an anterior segment observation optical system for observing an anterior segment of an eye E to be examined. This anterior ocular segment observation optical system 1 includes a half mirror 2, an objective lens 3,
It is roughly composed of a half mirror 4, an optical path switching mirror 5, and a CCD 6, and O1 is its optical axis. The anterior segment of the eye E is illuminated with infrared light by the anterior segment illumination light source 7. The half mirror 2 forms a part of the alignment optical system 8.
The alignment optical system 8 includes an alignment light source 9, a pinhole plate 10, a projection lens 11, a stop 12, and a half mirror 13, as shown in FIG. Pinhole plate 10
Is located at the focal point of the projection lens 11 and the pinhole plate 10
The alignment index light that has passed through is converted into a parallel light beam by the projection lens 11 and guided to the half mirror 2 via the half mirror 13. The parallel light beam is reflected by the half mirror 2 and guided to the cornea C. The alignment light source 9 blinks. The half mirror 13 is a fixation target projection optical system 14
Is part of.

The fixation target projection optical system 14 includes the fixation target light source 1.
7, a pinhole plate 18, an optical member 19 for presenting a plurality of fixation targets, and a projection lens 20. Fixation target light source 1
Reference numeral 7 is automatically turned on in association with the movement of the apparatus main body (not shown). Fixation target light from the fixation target projection optical system 14 is guided to the eye E through the half mirror 13 and the half mirror 2. At this time, the fixation target light is reflected on the reflection surface 19a of the optical member 19,
A plurality of fixation targets are presented to the eye E by being reflected a plurality of times at 19b. The subject fixes the fixation target according to the diopter, and performs the alignment adjustment while fixing the fixation target.

An alignment light beam K for aligning the apparatus main body with respect to the eye E in the up, down, left and right directions is guided to the cornea C as shown in FIG. The alignment light beam K has a corneal vertex P and a corneal curvature center O3.
A bright spot image R is formed at an intermediate position between the two. The reflected light beam is guided to the objective lens 3 via the half mirror 2. A part of the reflected light flux guided to the objective lens 3 is reflected by the half mirror 4, and the remaining reflected light flux passes through the half mirror 4. The light beam reflected by the half mirror 4 is guided to an alignment detection sensor 4 '. For example, the alignment detection sensor 4 '
A position sensor (PSD) is used. Approximate alignment in the optical axis direction between the apparatus main body and the subject's eye is performed through the anterior ocular segment observation optical system 1 in the same manner as the XY-direction alignment light beam, which is the reflected light of the irradiation light beam of the illumination optical system described later. The details of the rough alignment of the apparatus main body and the eye E in the optical axis direction will be described later.

The optical path switching mirror 5 is always retracted from the optical path of the anterior ocular segment observation optical system 1. The optical path switching mirror 5 has a light shielding surface 5a on one surface and a total reflection surface 5b on the other surface. The light beam that has passed through the half mirror 4 is guided to the CCD 6 to form an image, and a bright spot image is formed on the CCD 6. The half mirror 4 reflects a light beam from the alignment pattern projection optical system 21. The alignment pattern projection optical system 21 includes an alignment pattern light source 22, an alignment pattern plate 23, and a projection lens 24. An annular pattern is formed on the alignment pattern plate 23. The pattern forming light beam forming an annular pattern is reflected by the half mirror 4 and
And an annular pattern image is formed on the CCD 6.

The CCD 6 is connected to a monitor (not shown), and an image 26 of the anterior segment of the eye E is displayed on a screen 25 of the monitor as shown in FIG. Further, the annular pattern image 27 is similarly displayed. The apparatus main body (not shown) is swung up and down (Y direction) and left and right (X direction) so that the light beam reflected by the cornea C and forming the bright spot image R 'is located at the center of the annular pattern image 27. The adjustment is performed so that the optical axis O2 of the eye E to be examined matches the optical axis O1 of the apparatus. Further, the main body of the apparatus is moved back and forth (Z
The working distance is set to be shifted in the direction (direction), which will be described later as described above.

On both sides of the anterior ocular segment observation optical system 1, an illumination optical system 28 and an observation and photographing optical system 29 are provided. The illumination optical system 28 illuminates the cornea C of the eye E with an illumination light beam from an oblique direction. The illumination optical system 28 includes an illumination light source 30 for observation, a condenser lens 31, an infrared filter 31 ′, an illumination light source 32 for imaging, a condenser lens 33, and a slit plate 3.
4. It has a light projecting lens 35 and an optical member for optical path length correction 35 '. The illumination light source 30 and the illumination light source 32 are formed of a condenser lens 31.
Is conjugate with respect to FIG. 1 shows a state in which the optical path length correcting optical member 35 'is inserted into the optical path when observing endothelial cells, and the optical path length correcting optical member 35 is used when imaging with visible light.
'Is retracted from the optical path of the illumination optical system 28.

As the illumination light source 30, a halogen lamp is used, and as the illumination light source 32, a xenon lamp is used. The illumination light beam for observation becomes an infrared light beam because the infrared filter 31 'is inserted. The infrared light beam is emitted by the illumination light source 32.
Is once converged at the disposition position. This infrared light flux is guided to the condenser lens 33 as if it were emitted from the illumination light source 32. The infrared light flux condensed by the condenser lens 33 is guided to the slit plate 34. An elongated rectangular slit 36 is formed in the slit plate 34. The infrared light beam passes through the slit 36 and is guided to the light projecting lens 35. When the alignment of the apparatus main body with the eye E in the optical axis direction is completed, the slit plate 34 and the cornea C are substantially conjugate with respect to the light projecting lens 35, and the cornea C is irradiated with a slit light beam. This slit light beam crosses the cornea C from the surface T toward the inside.

The slit light beam is reflected by the cornea C. FIG. 5 shows the state of the reflection. Part of the slit light beam is first reflected on the corneal surface T, which is the interface between the air and the cornea C. The amount of the reflected light beam L from the corneal surface T is the largest. The amount of the reflected light flux M from the corneal endothelial cells N is relatively small. The light amount of the reflected light beam L 'from the corneal stroma M' is the smallest. Since a part of the slit light beam is reflected on the surface T of the cornea C, a part of the slit light beam reflected on the surface T is transmitted through the half mirror 2 and the objective lens 3 of the observation optical system 1. The light is guided to the half mirror 4.
A part of the reflected light beam guided to the Her mirror 4 passes through the half mirror 4 and is guided to the CCD 6. Therefore, as shown in FIG. 4, a vertically long slit-like reflection image 26 ′ by the slit illumination light beam is displayed on the screen 25 together with the anterior ocular segment image 26.
Will be reflected. This slit-shaped reflection image 26 ′
When the distance between the apparatus body and the eye E in the optical axis direction is excessively large (when the distance between the apparatus body and the eye E in the optical axis direction is larger than the proper working distance), the slit-shaped illumination light flux is transmitted to the cornea. Since the light is incident on the right side of C, the reflected image 26 'is formed on the right side of the corneal vertex P (the corneal vertex P and the bright spot image R' overlap), and when the apparatus body is brought closer to the eye E to be examined. ,
When the reflected image 26 'moves from right to left and approaches the corneal vertex M, and the distance between the apparatus main body and the eye E in the optical axis direction becomes an appropriate working distance, the reflected image 26' becomes the corneal vertex as shown in FIG. The image is projected almost overlapping P. Further, the apparatus body is brought closer to the eye E to be examined,
Is shorter in the optical axis direction (the main body of the apparatus and the eye E to be examined).
Is too small in the direction of the optical axis), the slit-shaped illumination light beam enters the left portion of the cornea C, and the reflected image 2
6 'is formed on the left side of the corneal vertex M as shown in FIG. Therefore, the examiner can see the reflection image 26 ′ displayed on the screen 25.
While observing the movement of the eye E, an approximate alignment operation of the apparatus optical system in the optical axis direction with respect to the eye E can be performed by manual operation. Since there is a difference corresponding to the thickness of the cornea C between the surface T of the cornea C and the corneal endothelium N, the position of the proper alignment in the optical axis direction is slightly shifted to the right. The light flux of the reflected image captured by the anterior ocular segment observation optical system 1 is reflected by the observation and imaging optical system 29.
Is smaller than the amount of light flux captured by

The observation and photographing optical system 29 includes an objective lens 40, an optical path length correcting member 40 ', a half mirror 41, a mask 42,
The relay lens 43, the mirror 44, the variable power lens 45, the focusing lens 46, and the optical path switching mirror 5 are roughly constituted. When the alignment in the optical axis direction is completed, the mask 42 and the cornea C are substantially conjugate with respect to the objective lens 40.

When the alignment of the apparatus optical system with respect to the subject's eye is completed, the alignment detection sensor 4 'outputs an alignment completion signal. The optical path switching mirror 5 is automatically inserted into the optical path of the anterior ocular segment observation optical system 1 based on the detection output of the alignment detection sensor 4 '. The light flux M reflected from the cornea C is condensed by the objective lens 40 and guided to the half mirror 41. A part of the reflected light beam is reflected by the half mirror 41 and guided to a line sensor 47 as a focus state detection sensor. The reflected light beam having passed through the half mirror 41 is guided to the mask 42, and an image of the corneal endothelial cells including the corneal endothelial cells N is formed at the position where the mask 42 is provided. Note that the mask 42 plays a role of blocking extra reflected light flux other than forming a corneal endothelial cell image. The reflected light beam forming the corneal endothelial cell image is guided to the optical path switching mirror 5 via the relay lens 43, the mirror 44, the variable power lens 45, and the focusing lens 46, is reflected by the optical path switching mirror 5, and forms an image on the CCD 6. Is done. Screen 2
5, a corneal endothelial cell image 48 is displayed as shown in FIG. In FIG. 8, reference numeral 49 denotes an optical image formed by the reflected light beam from the corneal surface T if the light is not blocked by the mask 42, and reference numeral 50 denotes an optical image formed by the reflected light beam from the corneal substance M '.

The line sensor 47 is arranged in the sectional direction of the cornea C as shown in FIG. 9B, and the intensity distribution of the reflected light beam is as shown in FIG. 9A. In FIG. 9A, reference symbol U denotes a peak due to a reflected light beam reflected on the surface T of the cornea C. Symbol V is cornea C
Of the endothelial cells. The peak U corresponds to the light image 49, and the peak V corresponds to the light image 48. Line sensor 4
The output of the element at each address 7 is input to a focus determination circuit 47 'as shown in FIG. The focus determination circuit 47 'is shown in FIG.
As shown in (a), all the signals including the peak U and the peak V are stored and subjected to arithmetic processing to determine the address of the peak V. Then, the focus determination circuit 47 'determines that the address L of the peak V is the center address Q of the line sensor 47.
It is determined whether or not they match. When the address L of the peak V coincides with the center address Q, the focusing judgment circuit 47 'outputs a photographing signal to the photographing light source emission control circuit 32', whereby the illumination light source 32 'emits light. Thus, the subject's eye E is illuminated with visible light, and the photographing is automatically performed.

As shown in FIG. 1, the optical path length correcting member 40 'is inserted into the optical path during observation with infrared illumination light, and is retracted from the optical path when photographing with visible light. At this time, a convex lens is used for the optical path length correction member 40 '. Conversely, a parallel plane plate or a concave lens is inserted into the optical path as an optical path length correcting member 40 ′ at the time of photographing to form a corneal endothelial cell image at a reference position, and the optical path length correcting member 40 ′ is moved at the time of observation. It is also possible to evacuate from.

Although the embodiment has been described above, the present invention is not limited to this, but includes the following.

The light source section including the illumination light source 30, the condenser lens 31, the infrared filter 31 ', the illumination light source 32 and the condenser lens 33 may be arranged as shown in FIG. In FIG. 10, 37 is a dichroic mirror, 38,
39 is a concave reflecting mirror. The dichroic mirror 37 is disposed between the condenser lens 31 and the slit plate 34, and transmits infrared light and reflects visible light.

[0024]

Further, in the embodiment, the alignment by manual operation has been described. However, also in the alignment by automatic operation, the reflected light of the illumination light of the illumination optical system from the cornea can be used.

[0026]

The corneal endothelial cell photographing apparatus according to the present invention comprises:
As described above, the illumination optical system
Reflection of a slit beam emitted from an angle from the corneal surface
Alignment of the device body with respect to the subject's eye in the optical axis direction based on the image
Operation at high magnification.
Faster alignment operation in the optical axis direction without the need
Can be planned.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an optical system showing an embodiment of a corneal endothelial cell observation and imaging apparatus according to the present invention.

FIG. 2 is a diagram showing an alignment optical system according to the present invention.

FIG. 3 is a diagram illustrating a reflection state of an alignment index light beam according to the present invention.

FIG. 4 is a diagram illustrating a display state of an anterior segment image, in which an optical axis distance of the apparatus main body to an eye to be inspected is excessive, and a reflection image of an illumination light beam is located on the right side with respect to a cornea vertex.

FIG. 5 is a diagram showing a reflection state of a slit light beam on the cornea.

FIG. 6 is a diagram illustrating a display state of an anterior segment image, in which a distance of an apparatus main body with respect to an eye to be examined in an optical axis direction is substantially appropriate, and a reflection image of an illumination light beam overlaps a vertex of a cornea.

FIG. 7 is a diagram illustrating a display state of an anterior segment image, in which a distance between the apparatus main body and an eye to be examined in an optical axis direction is too small, and a reflection image of an illumination light beam is located on the right side of a cornea vertex.

FIG. 8 is an explanatory diagram of a corneal endothelial cell image displayed on a screen of a monitor device.

FIG. 9 is a diagram showing a correspondence relationship between a corneal endothelial cell image and the amount of light received by a line sensor.

FIG. 10 is a diagram showing a modification of the illumination optical system of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Anterior eye observation optical system 26 '... Reflected image 28 ... Illumination optical system 29 ... Observation imaging optical system 30, 32 ... Illumination light source 32' ... Light emission amount control circuit 47 ... Line sensor (focus state detection sensor) E ... Eye to be examined C: Cornea N: Corneal endothelial cell

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 3/00-3/16

Claims (1)

(57) [Claims] An illumination optical system for obliquely irradiating a slit light beam to a cornea of an eye to be inspected, an imaging optical system for receiving reflected light from a corneal endothelial cell and photographing , and an apparatus for the eye to be inspected
Alignment optics for XY alignment of body
And a system, corneal endothelial cells photographing apparatus characterized by performing the optical axis direction of the alignment operation of the apparatus body with respect to the eye based on the reflected image from the cornea surface of the slit light flux.