JPH0767837A - Cornea endothelium photographing device - Google Patents

Abstract

PURPOSE:To provide a cornea endoshelium photographing device constituted so that an endothelium reflected light being much than an epithelium reflected light and a photographing adaptive position can be detected, when the eyeball surface is subjected to slit illumination and focusing is executed be using a cornea reflected light, at the time of enlarging and photographing a cornea endothelium cell of an eye to be examined. CONSTITUTION:When the eyeball surface 2 is subjected to slit illumination, and based on an illuminating light, an endothelium image of a part to be examined is formed in a focused state on the image receiving surface 22 of a television camera 23 through an enlarging/photographing optical system, a focusing detection photodetector 18 is set to a position for photodetecting an endothelium reflected light or an epithelium reflected light of a slit light on an optical axis 141 passing through an objective lens 15. A photodecting state of the slit light of this photodetector 18 is set so that a cornea endothelium reflected light can be detected surely, and a photographing adaptive position is detected at the time of advancing a photographing system 3 by a slit diaphragm 17 in front of the element and a detection slit diaphragm 7 in front of an illumination lamp 4, and raising the amplification gain of the element by catching a rise of an epithelium reflecting signal in the element concerned 18, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corneal endothelium photographing apparatus for magnifying observation or photographing a corneal endothelial cell of an eyeball of a subject.

[0002]

2. Description of the Related Art To see the effects of contact lenses,
It is necessary to observe the state of corneal endothelium in pre- and post-treatment of cataract surgery, and conventionally, for the purpose of magnifying observation or taking a magnified photograph of corneal endothelial cells of the eyeball of the subject, the eyeball of the subject's eye On the other hand, the objective lens of the microscope is a non-contact type or a contact type, and the slit illumination light is directed obliquely to the observed part toward the observed part, and the reflected light from the cornea is magnified for observation or slit illumination. By detecting the position of the light reflected from the corneal endothelium, the so-called triangulation principle is used to detect the imaging-compatible position where the corneal endothelium is in focus, and the corneal endothelium cells of the subject are photographed with a TV camera or the like. Is used.

However, in these conventional devices, a microscope mount equipped with a television camera is manually moved in the anteroposterior direction using an operating member such as a joystick to focus the corneal endothelium. However, when the subject is slit-illuminated and the corneal reflected light is used for focusing, the epithelial reflection is strong and the endothelial reflection is weak, and the difference is large, so it is difficult to detect the reflected light from the endothelium and the corneal endothelium is focused. There was a problem that it was difficult. Therefore, considerable effort and proficiency were required before focusing on the corneal endothelial cells in the test area.

The present invention has been made in view of the above-mentioned points, and does not require labor and proficiency, and after fixing the head of the examinee to the jaw stand, the examinee fixes the eye with the examinee's eye. Just by fixing the target and operating the machine, not only in the case of manual operation but also automatically, the corneal endothelium reflected light is detected easily and surely to detect the photographing compatible position, and the corneal endothelium cells of the test area are detected. It is an object of the present invention to provide an apparatus capable of performing magnified observation or magnified photographing.

[0005]

In order to achieve the above object, in a corneal endothelium imaging apparatus of the present invention, based on an illumination system for slit-illuminating an eye spherical surface of an eye to be inspected and a slit illumination light for illuminating the eye spherical surface. A magnifying photographing optical system for forming a magnified image of the part to be inspected, and when a corneal endothelium image is focused on the image plane of the magnifying photographing optical system, the slit light of the slit light is passed through at least the objective lens. Focus detection light receiving element that is set to receive corneal endothelium reflected light or corneal epithelium reflected light, and control the slit light reception state of the focus detection light receiving element to improve the detection ability of corneal endothelium reflected light It is composed of a light receiving state control means for performing the above operation, and a means for moving these device main bodies in the direction of the eye to be inspected so as to come to the focus position of the corneal endothelium.

As the light receiving state control means in the focus detecting light receiving element of the above-mentioned device, a slit-shaped diaphragm which is long in the longitudinal direction of the corneal reflection image by the slit illumination light is arranged in front of the focus detecting light receiving element. Is a good idea.

Further, as the light receiving state control means in the focus detecting light receiving element, the epithelium reflected light detection signal detected first by the focus detecting light receiving element is used to increase the light amount of the slit illumination of the illumination system. Alternatively, it is also effective to improve the detection ability of corneal endothelium reflected light by increasing the light receiving sensitivity of the focus detection light receiving element with the epithelial reflection detection signal.

Further, as the light receiving state control means in the focus detecting light receiving element, an optical system for compressing the longitudinal direction of the corneal reflection image by the slit illumination light may be arranged in front of the focus detecting light receiving element. .

Further, as the light receiving state control means in the focus detecting light receiving element, in the slit illumination optical system, a slit slit for detection narrower than the slit slit for photographing is provided separately from the slit slit for photographing. It is also effective to provide a diaphragm.

[0010]

In this apparatus, the magnified image of the endothelium of the subject is formed by the magnifying photographing optical system based on the reflected light from the spherical surface of the eye which is slit-illuminated by the illumination system. In this case, as shown in the principle of focusing of the cornea by the light receiving element using the so-called triangulation method in FIG. 2, the imaging system is manually or automatically advanced in the direction of the eye to be inspected, and the relative distance between the imaging system and the eye to be inspected. When there is a dynamic movement Em, the vertically long slit illumination light projected on the cornea 2 of the subject from the illumination optical axis 12 through the projection lens 13 causes the corneal epithelium to grow.
The slit-shaped epithelium reflected light 2ar reflected by the reflection part 2ar 'on the surface 2a moves through the objective lens 15 in the direction of the arrow Crm, which indicates the movement of the cornea reflected light, and the illumination light passing through the epithelium is illuminated by the illumination optical axis. The reflected light 2br on the corneal endothelium 2b surface is reflected by the reflection portion 2br 'on the surface of the corneal endothelium 2b, and similarly through the objective lens 15, the slit-shaped endothelial reflected light 2br follows the slit-shaped epithelial reflected light 2ar (with a small gap). Move in the above Crm direction in the adjacent state. The image receiving surface of the TV camera 23 (CCD light receiving surface:
(See FIG. 1) When the corneal endothelium image is focused in 22, the endothelial reflection light 2br (or epithelial reflection light 2ar) shown in FIG. Light 2br
When (or epithelial reflected light 2ar) enters, the corneal endothelium of the eye to be examined is focused on the light receiving surface of the TV camera, and the corneal endothelium image enlarged by the TV camera 23 via a monitor (not shown) is observed or photographed. can do.

In detecting the photographing position of the present apparatus, when the corneal endothelium reflected light is detected by the focus detecting light receiving element 18, the front side of the light receiving element 18 is seen in the direction of arrow C as the photographing system advances. The epithelium reflected light 2ar is followed by the endothelium reflected light 2br, and the light receiving signals of the epithelial reflection and the endothelium reflection are obtained from the light receiving element 18. However, the endothelium reflection, which is much weaker than the epithelial reflection, is the focus detection light receiving element. If a slit-shaped diaphragm, which is long in the longitudinal direction of the corneal reflection image by the slit illumination light, is arranged on the front surface of 18, the
As shown in, the peak of the endothelial reflection peak becomes clear compared to the case where there is no slit diaphragm in front of the light receiving element, the separation from the adjacent epithelial reflection can be improved, and the corneal endothelium reflected light can be reliably detected. can do.

Further, when the focus detection light-receiving element 18 detects the epithelial reflection light 2ar and then the endothelium reflection light 2br, the rise of a bright epithelial reflection light-reception signal detected earlier by the light-receiving element 18 is detected. This is triggered by switching the illumination lamp voltage UP or opening the diaphragm in the illumination optical system to increase the slit illumination light amount to make it brighter, or by switching the gain switching of the light receiving element 18 amplifier to receive light. The gain of the endothelium reflected light reception signal in the element 18 can be increased (see FIG. 4), and the corneal endothelium reflected light can be reliably detected.

On the other hand, by arranging an optical system (for example, a cylindrical lens) for compressing the longitudinal direction of the corneal reflection image by the slit illumination light in front of the focus detection light receiving element 18, a slit-shaped corneal reflection image is formed. The entire light receiving element can be received without waste, and the ability of the light receiving element 18 to detect corneal endothelium reflected light can be improved.

Further, in the above slit illumination optical system, if a slit diaphragm for detecting a photographing position, which is narrower than the slit diaphragm for photographing, is used separately from the slit diaphragm for photographing, it is detected as compared with the conventional diaphragm for photographing. A slit-like diaphragm having a narrower width than that of the slit-like diaphragm that also serves as a dual purpose can be used for detecting the photographing position, and is a diagram showing the relationship between the light receiving element and corneal reflected light as viewed in the direction of arrow C in FIG. As shown in FIGS. 5 (a) and 5 (b), at the time of shooting illuminated by slit light for shooting, the corneal reflected light 2ar, 2br having a width sufficiently wider than the light receiving area 18a of the light receiving element whose width is narrowed by the slit diaphragm. While it is possible to capture a wider field of view than before, at the time of detection illuminated by the slit light for detection, the corneal reflected light 2ar, 2br with a narrower eye width than the light receiving area 18a of the above light receiving element is detected.
Therefore, it is possible to detect the photographing position by detecting the corneal endothelium reflex with higher positional accuracy than before. The arrow in FIG. 5 indicates the moving direction of the corneal reflected light 2ar, 2br when the imaging system is advanced in the direction of the eye to be examined, and the image 2ar of the corneal epithelium reflected light and the corneal endothelium reflected light in FIG. Light statue 2b
Actually, r has an unclear contour as shown in FIG. 6 due to reflection from a living body, but is simplified in FIG. 5 for the purpose of facilitating the explanation.

[0015]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an optical path diagram of the above embodiment.

In FIG. 1, an illumination system for irradiating the eye spherical surface 2 of the eye 1 to be inspected with a slit and a slit illumination light for irradiating the eye spherical surface facing the eye spherical surface 2 with a television camera 23 for magnifying observation or inspection of the inspected portion. It is composed of a magnifying photographing optical system capable of taking magnified photographs, and a part of the optical path of the magnifying photographing optical system is extended to detect corneal endothelium reflection (or corneal epithelial reflection) of a subject to be photographed. An imaging system 3 including a focus detection light-receiving element 18 for detecting a matching position is shown, and the imaging system 3 is moved in the axial direction of the eye 1 to be inspected by a driving unit (not shown).

An illumination lamp 4 used as a light source for illuminating the part to be inspected on the ocular spherical surface 2 during focusing of the magnifying photographing optical system.
And the stroboscopic discharge tube 8 used at the time of taking a magnified photograph of the corneal endothelial cells, the respective light emitted from the illumination optical axis 12 through the projection lens 13 to the cornea 2 which is the surface to be observed of the eye 1 to be inspected,
The stroboscopic discharge tube 8 illuminates at a predetermined position on the illumination optical axis 12 and the illumination lamp 4 illuminates via the half mirror 11 on the illumination optical axis 12 so as to irradiate the eye axis at a predetermined angle from the oblique direction. It is provided on the optical axis perpendicular to the optical axis 12.

Then, the light emitted from the illumination lamp 4 is placed at the focus position of the condenser lens 5 at the light receiving element for focus detection described later.
18 A slit slit 7 for detection having a narrow predetermined width corresponding to the slit diaphragm 17 on the front surface is provided, while the light emitted from the stroboscopic discharge tube 8 is focused at a focusing position by a condenser lens 9 and can be photographed in a wide field of view. The slit mirror 10 for photographing having a predetermined width is provided, and the visible light cut filter 6 is provided on the optical axis of the illumination lamp 4 in front of the slit 7 for detection.
At 11, only the infrared light of the illumination lamp 4 is reflected and the eye spherical surface 2
On the other hand, visible light from the strobe discharge tube 8 is transmitted through the half mirror 11 and projected onto the ocular spherical surface 2.

Further, on the opposite side of the axial 2 ₁ of the eye and the illumination optical axis 12 of the illumination system, the cornea of the oblique slit-shaped illumination light by the illumination lamp 4 or the strobe discharge tube 8 to the eyeball surface 2 A magnifying photographing optical system for magnifying and observing a corneal endothelium image of a portion to be observed by receiving reflected light from the observed portion is formed on an image receiving surface (CCD light receiving surface) 22 of a television camera 23. When the corneal endothelium image is focused on the image receiving surface 22 of the television camera 23, the focus detection light receiving element is set at a position where a part of the optical path of the optical system is extended.
Reference numeral 18 is adapted to detect corneal endothelium reflected light (or corneal epithelium reflected light) moving on the front surface of the focus light receiving element as the imaging system 3 advances.

[0020] That is, the optical axis of the enlarged image taking optical system in the illumination optical axis 12 and symmetrical position of the illumination system across the axial 2 ₁ of the eye 1
An objective lens 15 on the eyeball side at a predetermined position on 14 ₁ and a half mirror (infrared light transmission / visible light reflection) 16 at a predetermined distance from the objective lens 15 and a predetermined distance from the optical axis 14 ₁ an image light by the reflected light of the illumination light from the angle crossed to the eyeball surface is arranged to bending so as to be perpendicular to the predetermined position of the substantially axial line of the axial 2 _1, the image light reflected by the half mirror 16 photographing slit light by the strobe light out of the enlarged image rays by the optical axis 14 ₂ top through the field stop 19 and the magnifying lens 20 is located on an intermediate image plane the axial 2 ₁ direction 45 ° crossover mirrors 21 Visible light is totally reflected and the bent optical axis 14
While incident on the image receiving surface (CCD light receiving surface) 22 of the television camera 23 provided on the above ₃ , the infrared light of the slit light for detecting the photographing position extends the optical path on the optical axis 14 ₁ and the objective lens.
The light is incident on the focus detection light receiving element 18 provided at the image forming position of the cornea reflected image light beam by 15. And
When the corneal endothelium image is focused on the image receiving surface 22 of the television camera 23 by the objective lens 15 and the magnifying lens 20, the slit-shaped endothelium reflected light is the corneal reflected image in front of the focus detection light receiving element 18. A slit diaphragm 17 which is long in the longitudinal direction improves the separation from adjacent epithelial reflections (see FIG. 3), and the slit diaphragm 7 at the focusing position of the light emitted from the illumination lamp 4 narrows the width of the light receiving element. 18 light receiving areas
By the slit light for detection incident on 18a (see Fig. 4),
The light receiving element 18 can detect the corneal endothelium reflected light with high position accuracy and reliably to detect the photographing compatible position of the apparatus.

At this time, by detecting the rising of the epithelial reflection light reception signal which comes first from the focus detection light receiving element 18, the slit illumination light amount is increased by switching the voltage UP of the illumination lamp 4 to detect darkness. It is possible to detect the endothelial reflected light by making the difference in intensity between the epithelial reflected light and the endothelial reflected light to be surely detected by brightening the endothelial reflected light, which is difficult to detect. It is also possible to increase the sensitivity of the light receiving element by switching the switching so that the endothelium reflected light can be reliably detected, and further, a cylindrical lens is arranged in front of the light receiving element 18 to form a slit-shaped corneal reflection image. For example, it is possible to efficiently detect the corneal endothelium reflection by receiving the whole with the light receiving element without waste. The controlled using various means to improve the detection capability of the corneal endothelial reflected light, it is possible to reliably detect the shooting matching position of the to apparatus to detect the corneal endothelial reflected light.

When the photographing system 3 is set to the photographing suitable position, that is, when the image of the corneal endothelium on the image receiving surface 22 of the television camera 23 is focused, the photographing system 3 is manually operated by using an operation member such as a joystick. By moving the gantry mounted with the in the direction of the eye to be inspected, the display lamp and the buzzer using the focus signal from the focus detection light-receiving element 18, it is possible to easily set the shooting compatible position of the device, The gantry equipped with the imaging system 3 is moved forward from the standby position toward the subject's eye by an arbitrary signal such as a signal that alignment light enters a predetermined area of the anterior segment image with an anterior segment imaging device (not shown), and the above-mentioned focusing is performed. When detecting the epithelial reflex after detecting the epithelial reflex with the detection light receiving element, the advancement of the gantry can be stopped so that the photographing compatible position can be automatically detected.

[0023]

According to the apparatus for photographing corneal endothelium of the present invention described in claim 1, when photographing corneal endothelial cells of an eye to be examined,
By controlling the light receiving state of the slit light in the light receiving element for focus detection mounted on the main body of the device, the corneal endothelium reflected light that is far weaker than the corneal epithelium reflected light can be reliably detected by the light receiving element. It is possible to easily and surely detect the photographing suitable position of not only manually but also automatically and perform photographing.

According to the second aspect of the present invention, when the focus detection light receiving element detects the cornea reflected light of the eye to detect the focus, the corneal endothelium reflected light is separated from the adjacent epithelial reflected light. It can be improved and detected reliably.

According to the third aspect of the invention, when detecting the cornea reflected light of the eye to be inspected by the focus detecting light receiving element to detect the focus, the inner reflected light which is dark and difficult to detect is brightened,
The intensity difference between the epithelial reflection and the endothelium reflection can be reduced, and the corneal reflection light can be detected reliably.

According to the fourth aspect of the present invention, when the focus detection light receiving element detects the corneal reflected light of the eye to detect the focus, it has a high light receiving sensitivity for the dark reflected endothelial light which is difficult to detect. The light receiving element can reduce the detection signal difference between epithelial reflection and endothelium reflection, and can reliably detect corneal endothelium reflection light.

According to the fifth aspect of the invention, when the focus detecting light receiving element detects the cornea reflected light of the eye to detect the focus, the entire slit-shaped corneal reflection image is wasted by the light receiving element. Therefore, it is possible to improve the detection capability of the corneal endothelium reflected light in the focusing light receiving element.

According to the sixth aspect of the present invention, the slit illumination optical system has the slit-shaped diaphragm for detection separately from the one for photographing, so that the dimension of the slit illumination in the width direction is properly used according to the purpose, and the corneal endothelium is used. It is possible to detect reflected light with high precision and photograph a wide field of view.

[Brief description of drawings]

FIG. 1 is an optical path diagram of an embodiment of the present invention,

FIG. 2 is a perspective view showing the focusing principle in FIG.

FIG. 3 is a curve diagram showing a separation state of epithelial reflection and endothelial reflection with and without a slit diaphragm on the front surface of the light receiving element,

FIG. 4 is a curve diagram of a light receiving signal when the light receiving element gain is increased by capturing the rising of the epithelial reflection light receiving signal in the light receiving element,

FIG. 5 is a schematic diagram showing a relationship between a light receiving area of a light receiving element and corneal reflected light at the time of conversion of a diaphragm for slit illumination optical system detection and shooting.

FIG. 6 is an actual corneal reflected light diagram at the time of photographing.

[Explanation of symbols]

1 ... Eyeball, 2 ... Eye spherical surface (cornea), 3 ... Imaging system, 4
... lighting lamps, 7 ... throttle detection slit, 8 ... flash discharge tube, 10 ... photographic stop slit, 11 ... infrared reflecting and visible light-transparent mirror, 12 ... illumination optical axis, 13 ... projection lens, 14 _1, 14 ₂ , 14 ₃ … Magnification optical axis, 15… Objective lens, 16… Infrared light transmitting / visible light reflecting mirror, 17… Slit diaphragm, 18… Focus detection light receiving element, 20… Magnifying lens, 21… Mirror , 22 ... CCD light receiving surface (image receiving surface),
23 ... TV camera.

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[Procedure amendment]

[Submission date] October 8, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

However, in these conventional apparatuses, a corneal endothelium is constructed by manually moving a microscope mount equipped with a television camera in the anteroposterior direction by using an operation member such as a joystick. However, when the subject is slit-illuminated and focused using the corneal reflected light, the epithelial reflection is strong and the endothelial reflection is weak, and the difference is large, so it is difficult to detect the endothelium reflected light. However, there was a problem that it was difficult to focus the corneal endothelium. for that reason,
It took considerable time and proficiency to focus on the corneal endothelial cells in the test area.

Claims (6)

[Claims] 1. An illumination system for slit-illuminating an eye spherical surface of an eye to be inspected, a magnifying photographing optical system for forming a magnified image of a subject on the basis of slit illumination light irradiating the eye spherical surface, and the magnifying photographing optical. When the corneal endothelium image is focused on the image plane of the system, the focus detection light is set at the position to receive the slit corneal endothelium reflected light or the corneal epithelium reflected light through the objective lens. Element, a light receiving state control means for controlling the light receiving state of the slit light in the light receiving element for focus detection to improve the detection ability of corneal endothelium reflected light, and the device main body so as to come to the corneal endothelium in-focus position. A device for moving a corneal endothelium, comprising means for moving the eye toward the subject's eye. 2. The light receiving state control means in the focus detecting light receiving element is a slit-shaped diaphragm which is arranged in front of the focus detecting light receiving element and is long in the longitudinal direction of the corneal reflection image by the slit illumination light. Item 2. The corneal endothelium imaging apparatus according to Item 1. 3. The light receiving state control means in the focus detecting light receiving element increases the slit illumination light amount of the illumination system by the epithelium reflected light detection signal from the focus detecting light receiving element. Corneal endothelium imaging device. 4. The light receiving state control means in the focus detecting light receiving element increases the light receiving sensitivity of the focus detecting light receiving element by the epithelium reflected light detection signal from the focus detecting light receiving element. The corneal endothelium imaging apparatus described. 5. The light receiving state control means in the focus detecting light receiving element is an optical system arranged in front of the focus detecting light receiving element to compress the longitudinal direction of the corneal reflection image by the slit illumination light. The corneal endothelium imaging apparatus according to 1. 6. A light receiving state control means in the focus detecting light receiving element is a slit slit for detection which is narrower than the slit slit for photographing provided separately from the slit slit for photographing in the slit illumination optical system. The corneal endothelium imaging apparatus according to claim 1.