JPH10328143A - Slit lamp - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A slit lamp capable of efficiently illuminating an eye to be examined in various diagnostic methods. An illumination optical system (1) for forming a ring-shaped slit light (10) on an eye to be inspected (20) and an eye to be inspected based on light reflected from the eye to be illuminated by the illumination optical system. (2, 17 to 19) for observing or photographing the image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slit lamp, and more particularly to a slit lamp used for diagnosis of an anterior segment of an eye to be examined.

[0002]

2. Description of the Related Art Conventionally, a slit lamp has been used as a useful diagnostic device for diagnosing an anterior eye portion such as a cornea and a crystalline lens of an eye to be examined. In diagnosing transparent tissues such as the cornea and the lens, ordinary illumination is not sufficient. In particular, for cross-sectional observation of a cornea, a crystalline lens, or the like, slit illumination utilizing the Tyndall phenomenon is essential.

Further, as a technique for diagnosing the anterior segment, in addition to the direct observation method of directly observing the illuminated portion, for example, slit light is applied to the iris portion in the back through the cornea, and based on the reflected light, the corneal portion is irradiated. There is an indirect lighting method to observe the lesion. In addition, the slit light is applied to the fundus, and the transillumination method is used to observe the turbidity of the crystalline lens using reflection from the fundus, or the slit light is applied to the sclera in contact with the limbus to scatter light inside the cornea. There are various observation methods such as a scleral scattering method for observing a lesion inside the cornea.

[0004]

However, a conventional slit lamp is configured to form a slit light in a vertical direction (vertical direction) on the eye under normal conditions. Therefore, for example, when observing the cross section of the cornea, the slit stop in the illumination optical system is set to 90 degrees around the optical axis.
After rotation, the optical axis of the illumination optical system had to be tilted with respect to the optical axis of the observation optical system.

[0005] Further, a conventional slit lamp is configured to form one slit light on the eye to be examined. Therefore, in the indirect illumination method, only a narrow area can be illuminated by one slit light, and it is necessary to move the slit light to observe a wide area. further,
Also in the scleral scattering method described above, slit light is incident from one side of the corneal limbus, so that it is difficult to obtain efficient illumination over the entire cornea.

[0006] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a slit lamp capable of efficiently illuminating an eye to be examined in various diagnostic methods.

[0007]

According to the present invention, there is provided an illumination optical system for forming a ring-shaped slit light on an eye to be inspected, and the illumination optical system illuminated by the illumination optical system. Observation photographing optical system for observing or photographing the subject's eye based on reflected light from the subject's eye,
Provided is a slit lamp characterized by comprising:

According to a preferred aspect of the present invention, the illumination optical system includes a diaphragm having a ring-shaped slit transmitting portion disposed at a position optically substantially conjugate with the eye to be inspected;
Light source means for illuminating the ring-shaped slit transmitting portion of the aperture means, wherein light transmitted through the ring-shaped slit transmitting portion has an outer diameter smaller than 14 mm on the subject's eye. To form a slit light beam.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a slit lamp according to the present invention, for example, a diaphragm means having a ring-shaped slit transmitting portion, that is, a ring slit diaphragm is illuminated, and light transmitted through the ring-shaped slit transmitting portion is, for example, 14 m on the eye to be examined.
A ring-shaped slit light having an outer diameter smaller than m is formed.

Therefore, in the present invention, the arc-shaped slit light, which is composed of a part of the ring-shaped slit image and extends in the entire vertical direction (vertical direction) on the cornea of the eye to be examined, is moved in the horizontal direction. Observation of the longitudinal section of the cornea can be performed. Further, by moving the arc-shaped slit light, which is composed of a part of the ring-shaped slit image and extends generally in the horizontal direction (lateral direction), in the vertical direction, the cross section of the cornea can be observed. That is, in the present invention, the switching operation from the longitudinal section observation to the transverse section observation of the cornea can be quickly performed.

Further, according to the present invention, since the ring-shaped slit light can be applied to the entire iris, a bright indirect illumination method can be performed over a wide area surrounded by the ring-shaped slit light. Furthermore, in the present invention, by illuminating the entire limbus with a ring-shaped slit light having an outer diameter slightly larger than the corneal diameter, the entire cornea can be efficiently illuminated. It is possible to do. As described above, according to the slit lamp of the present invention, it is possible to quickly perform the switching operation from the longitudinal cross-sectional observation to the cross-sectional observation of the cornea, and to perform observation using bright and wide-range indirect illumination and the like. The eye to be examined can be efficiently illuminated in various diagnostic methods.

An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating a configuration of a slit lamp according to an embodiment of the present invention. The slit lamp in FIG. 1 includes an illumination light source 3 such as a lamp light source. Light emitted from the illumination light source 3 illuminates a slit aperture 6 and a ring slit aperture 7 via a condenser lens 4. The slit aperture 6 has a single linear slit opening (light transmitting portion) according to the related art. The ring slit aperture 7 has a ring-shaped slit opening (light transmitting portion) as described later with reference to FIG.

Accordingly, for example, the light transmitted through the ring-shaped slit opening of the ring slit stop 7 when the slit stop 6 is retracted from the optical path passes through the relay lens 8 and the prism 9 as light deflecting means. The eye reaches the subject's eye 20. Here, the slit stop 6 and the ring slit stop 7 are positioned almost conjugate with the eye 20 by the relay lens 8. Therefore,
On the eye to be inspected 20, a ring-shaped slit image 10 corresponding to the ring-shaped slit opening of the ring slit aperture 7 is formed. As described above, the illumination light source 3, the condenser lens 4, the ring slit diaphragm 7, the relay lens 8, and the prism 9 constitute the illumination optical system 1 for forming a ring-shaped slit light on the subject's eye 20. .

The reflected light from the subject's eye 20 illuminated with the ring-shaped slit image 10, ie, the ring-shaped slit light, is transmitted to the objective lens 11 and the variable power lens group 12 which are shared by the observation optical system and the photographing optical system. Incident. Objective lens 1
The light passing through the first lens unit and the variable power lens group 12 is guided to either the observation optical system or the photographing optical system by the action of the mirror 16 for switching the optical path.

For example, when the optical path switching mirror 16 is retracted from the optical path, the reflected light from the subject's eye 20 is guided to the observation optical system. The light guided to the observation optical system forms two images of the subject's eye 20 via the left and right observation imaging lenses 13 and the right and left erect prisms 14. The formed two images of the subject's eye 20 are magnified and observed through the left and right eyepieces 15. As described above, the objective lens 11, the variable power lens group 12, the observation imaging lens 13, the erecting prism 14, and the eyepiece 15 are based on the reflected light from the eye 20 illuminated by the illumination optical system 1. An observation optical system 2 such as a stereoscopic microscope for observing the subject's eye 20 is configured.

On the other hand, when the optical path switching mirror 16 is positioned on the optical path as shown in FIG. 1, the light from the subject's eye 20 is reflected by the mirror 16 and guided to the photographing optical system. The light guided to the photographing optical system is transmitted to the imaging lens 17 for photographing.
Further, an image of the eye to be inspected 20 is formed on the light receiving surface of the light receiving unit 19 for photographing via the mirror 18 as a light deflecting unit.
As described above, the objective lens 11, the variable power lens group 12, the imaging lens 17 for imaging, the mirror 18, and the light receiving unit 19 for imaging are based on the reflected light from the eye 20 illuminated by the illumination optical system 1. An imaging optical system for imaging the eye to be inspected 20 is configured. If a light source for photographing is required in the illumination optical system 1, for example, a strobe light source can be disposed at a position optically conjugate with the illumination light source 3.

FIG. 2 is a diagram schematically showing the configuration of the ring slit stop of FIG. As shown in FIG. 2, the ring slit stop 7 is a turret (rotating plate) configured to be rotatable about a point 7c. In the ring slit aperture 7, a circular opening 71 and three ring-shaped slit openings (light transmitting portions) 72 to 74 having different shapes are formed on the circumference around the point 7c. . Therefore, by rotating the ring slit stop 7 about the point 7c, each of the apertures 71 to 71 is provided in the optical path of the illumination optical system 1.
74 can be positioned.

Thus, for example, by disposing the slit stop 6 in the optical path of the illumination optical system 1 and positioning the circular opening 71 of the ring slit stop 7 in the optical path of the illumination optical system 1, the slit aperture 6 can be covered in accordance with the prior art. Optometry 20
One linear slit image can be formed thereon. In addition, the slit stop 6 is retracted from the optical path of the illumination optical system 1, and an arbitrary ring-shaped slit opening of the ring slit stop 7 is positioned in the optical path of the illumination optical system 1, so that a ring is formed on the eye 20 to be examined. It is possible to form a slit image of a shape. In this case, the shape of the ring-shaped slit image formed on the subject's eye 20 can be changed by switching the ring-shaped slit opening positioned in the optical path of the illumination optical system 1.

FIG. 3 is a view showing a ring-shaped slit image formed on the eye to be examined according to the present embodiment. FIG. 4 is a diagram showing one linear slit image formed on the eye to be examined according to the related art. As shown in FIG. 3, in the present embodiment, a ring-shaped slit image 22 is formed on the cornea 21 of the subject's eye 20. Therefore, information on the corneal section 23 illuminated by the ring-shaped slit image 22 can be obtained via the observation optical system and the imaging optical system. On the other hand, as shown in FIG. 4, in the related art, one linear slit image 24 is formed on the cornea 21 of the eye 20 to be examined, and the corneal cross section 25 is illuminated.

As described above, in this embodiment, the whole of the illumination optical system 1 is angled in the horizontal direction with respect to the optical axis of the observation optical system, so that the ring-shaped slit image 22 is formed on the cornea 21 of the eye 20 to be examined. An arcuate slit cross section that is partially formed and extends in the entire vertical direction (longitudinal direction) can be obtained. As a result, information on the corneal longitudinal section illuminated by the arcuate slit light extending in the entire vertical direction can be obtained over the entire cornea 21.

In this embodiment, the illumination optical system 1 is tilted in the direction perpendicular to the horizontal direction with respect to the optical axis of the observation optical system, so that a ring-shaped slit is formed on the cornea 21 of the eye 20 to be examined. An arcuate slit cross section that is formed by a part of the image 22 and extends in the entire horizontal direction (lateral direction) can be obtained. As a result, the information of the corneal cross section illuminated by the arc-shaped slit light extending in the lateral direction as a whole is transmitted to the cornea 2.
1 can be obtained throughout. In this case, in the prior art, after the slit diaphragm 6 is rotated by 90 ° around the optical axis, the illumination optical system is turned on in order to obtain the slit light of the cross section of the horizontal linear slit light formed on the cornea. An operation of tilting with respect to the axis was required. As described above, in the present embodiment, the switching operation from the longitudinal section observation to the transverse section observation of the cornea can be performed quickly.

Also, in the indirect illumination method of irradiating slit light to the iris portion and observing a corneal lesion based on the reflected light, conventionally, only a portion of the iris can be irradiated with light, and a wide area can be irradiated. Could not be observed. However, in this embodiment, since the ring-shaped slit light can be applied to the entire iris, a bright indirect illumination method can be performed over a wide area surrounded by the ring-shaped slit light.

Further, in this embodiment, the entire cornea limbus can be efficiently illuminated by illuminating the entire limbus with a ring-shaped slit light having an outer diameter slightly larger than the corneal diameter (diameter). And a bright scleral scattering method can be performed. In this case, since the corneal diameter is about 10 mm, a ring-shaped slit image is at most 14 m.
m is required. As described above, according to the slit lamp of the present embodiment, it is possible to quickly perform the switching operation from the longitudinal cross-sectional observation to the cross-sectional observation of the cornea. In the method, the subject's eye can be efficiently illuminated.

FIG. 5 is a diagram schematically showing a configuration of a modification of the ring slit diaphragm of FIG. The ring slit diaphragm 7 according to the modified example is configured by an electric dimming element (for example, a liquid crystal display element, an all solid electrochromic element, etc.) fixed in the optical path of the illumination optical system 1. That is, in the ring slit diaphragm 7 of FIG. 5, three ring-shaped slit regions 75 to 77 formed continuously concentrically.
Is configured to be able to independently change the transmittance. Therefore, for example, when only the region 75 is in the light transmitting state and the other regions are in the light blocking state, a ring-shaped slit transmitting portion having the largest outer diameter can be formed.

For example, when only the region 77 is in the light transmitting state and the other regions are in the light blocking state, a ring-shaped slit transmitting portion having the smallest outer diameter can be formed. Further, for example, when the regions 75 and 76 are in the light transmitting state and the region 77 is in the light blocking state, a ring-shaped slit transmitting portion having the largest outer diameter and the widest width can be formed. Thus, in the ring slit diaphragm 7 of the modified example,
By switching the transmittance of each slit region, the outer diameter and width of the ring-shaped slit transmitting portion, and thus the outer diameter and width of the ring-shaped slit light formed on the eye to be inspected, can be appropriately changed.

In the embodiment described above, three ring-shaped slit openings 72 to 74 are formed in the ring slit diaphragm 7. In the above-described modified example, three ring-shaped slit regions 75 to 77 are formed in the ring slit diaphragm 7. However, it goes without saying that the number and shape of the ring-shaped slit openings and the ring-shaped slit regions formed in the ring slit stop 7 can be changed without being limited to the above-described embodiments and modifications. Also,
In the above embodiment, the mirror 16 is used for switching the optical path. However, a light splitting unit such as a half mirror can be used instead of the mirror 16.

[0027]

As described above, according to the present invention,
The switching operation from the longitudinal cross-sectional observation to the cross-sectional observation of the cornea can be quickly performed, and observation with bright and wide-range indirect illumination can be performed. As a result, it is possible to realize a slit lamp that can efficiently illuminate the eye to be examined in various diagnostic methods.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a configuration of a slit lamp according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a configuration of a ring slit stop of FIG. 1;

FIG. 3 is a diagram showing a ring-shaped slit image formed on an eye to be examined according to the present embodiment.

FIG. 4 is a view showing an embodiment 1 formed on a subject's eye according to the prior art.
It is a figure which shows the linear slit image of a book.

FIG. 5 is a diagram schematically showing a configuration of a modification of the ring slit diaphragm of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 illumination optical system 2 observation optical system 3 illumination light source 4 condenser lens 6 slit aperture 7 ring slit aperture 8 relay lens 9 prism 10 ring-shaped slit image 11 objective lens 12 variable power lens group 13 observation imaging lens 14 erect Prism 15 Eyepiece lens 16 Optical path switching mirror 17 Imaging lens for imaging 18 Mirror 19 Light receiving means for imaging 20 Eye to be examined 21 Cornea

Claims (4)

[Claims] An illumination optical system for forming a ring-shaped slit light on the eye to be inspected; and observing or photographing the eye to be inspected based on reflected light from the eye to be illuminated by the illumination optical system. A slit lamp characterized by comprising: 2. An illumination optical system comprising: a diaphragm having a ring-shaped slit transmitting portion disposed at a position optically substantially conjugate with the eye to be inspected; and the ring-shaped slit transmitting portion of the diaphragm being And a light source means for illuminating, wherein the light transmitted through the ring-shaped slit transmitting portion forms a ring-shaped slit light having an outer diameter smaller than 14 mm on the eye to be examined. The slit lamp according to claim 1. 3. The stop means has a rotating plate having a plurality of ring-shaped slit transmitting portions having different shapes formed on a circumference, and the plurality of ring-shaped slit transmitting portions are arranged on an optical path of the illumination optical system. 3. The slit lamp according to claim 2, wherein the shape of the ring-shaped slit light formed on the eye to be inspected is changed by switching the slit transmitting portion. 4. The diaphragm means includes an electric dimming element fixed in an optical path of the illumination optical system and having a plurality of ring-shaped slit regions formed continuously concentrically. The slit lamp according to claim 2, wherein the shape of the ring-shaped slit light formed on the eye to be inspected is changed by switching the transmittance of the slit region.