JPS6117494B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to ophthalmological instruments, and particularly to a device suitable for detecting and measuring visual field.

Perimetry is an important clinical test in ophthalmology, and the position of this field is becoming increasingly important in relation to cranial nerve diseases. By the way, with the currently commonly used perimetry, it is not possible to directly observe the retinal region of the eye being examined, and it is not possible to directly observe the retinal region of the subject's eye, for example, and it is not possible to directly observe the retinal region of the subject's eye, and it is not possible to directly observe the retinal region of the subject's eye. It is not possible to know exactly what is there. Furthermore, during measurement, the subject is gazing at a fixed visual target, but even if the subject's line of sight moves, it is difficult to check with conventional equipment.

The object of the present invention is to make it possible to know the exact positional relationship between the measurement results and the fundus of the eye, and also to check the direction of the subject's line of sight.

FIG. 1 shows an embodiment of the invention. In this embodiment, infrared rays are used as the fundus illumination light flux, but the invisible light may also be a combination of weak light and a high-sensitivity imaging tube, for example.

In the figure, E is the eye to be examined, and E is the fundus (retina). Further, 1 is a tungsten lamp, which is a light source for illumination, 2 is a condenser lens, and 3 is a strobe tube, which is a light source for photographing. 4 is another condenser lens, and 5 is a mirror for bending the optical path. 6
2 is a ring slit plate having a ring-shaped opening, and its plan view is shown in FIG. The ring slit plate is common with the light source 1 with respect to the condenser lenses 2 and 3 and with the light source 3 with respect to the condenser lens 4.

7 and 8 are relay lenses, and 9 is a perforated mirror, which has an aperture in the center, and the periphery of the aperture is a mirror surface, and this mirror surface is common to the ring slit plate 6 for the relay lenses 7 and 8 It is. Reference numeral 10 denotes an aperture diaphragm, whose function in conjunction with the ring slit plate 6 described above to prevent corneal reflection is well known.

Reference numeral 11 indicates an objective lens, and reference numeral 14 indicates an imaging lens group, both of which are arranged with their optical axes aligned. Once an image is formed by the objective lens, the imaging lens group directs the light beam that has passed through the aperture 10 to the image plane 30. re-image.

15 is a flip-up mirror, 16 is a field lens,
The field lens is provided in common with the image plane 30 with respect to the mirror surface of the flip-up mirror. 17 is a semi-transparent mirror for bending the optical path; 18 is an imaging lens; 19 is an imaging tube sensitive to infrared wavelengths; be. 20 is a cathode ray tube, which is the above-mentioned image pickup tube 1.
The output of 9 is input to a cathode ray tube via a processing circuit (not shown). Further, a member 21 provided between the observation light source 1 and the condenser lens 2 is an infrared filter that blocks visible light and passes infrared light.

The members 1 to 21 described above have a structure corresponding to a non-mydriatic fundus camera.

Next, 22 is a tungsten lamp, and 22 is a light shielding plate with a minute aperture as shown in Fig. 4. Both constitute an index light source for visual field measurement, and are movable in the left and right directions in the figure or in the direction perpendicular to the drawing. shall be.

Further, 24 is a projection lens, 25 is a semi-transparent mirror such as a pellicle mirror, and 26 is a concave spherical mirror.
At the same time, the projection lens 24 is almost synchronized with the light shielding plate 2.
3 and the image plane 30, the light beam emitted from the index light source that passes through the semi-transparent mirror forms an image on the concave mirror, and the light beam reflected by the semi-transparent mirror is reflected by the flip-up mirror 15. An image is formed on the field lens 16.

27 is a projection lens, 28 is a light-shielding plate having a minute aperture as shown in FIG. 5, and 29 is a tungsten lamp. The lamp 29 and the light-shielding plate 28 constitute a fixation light source. The light beam emitted from this fixation light source is transmitted to the projection lens 27
As a result, an image is formed on the image plane on the field lens 16. Note that the fixation light source may be made to blink in order to maintain the gaze. The reason why the mirror 26 is made concave rather than flat is to provide an effect equivalent to a field lens, but a diffuser plate may be provided in place of the concave mirror 26. Here, a tungsten lamp 22, a light shielding plate 23, a projection lens 24,
The semi-transparent mirror 25 (light beam transmission), the concave spherical mirror 26, the semi-transparent mirror 25 (light beam reflection), the imaging lens group 14, and the objective lens constitute the first projection means.

Further, the objective lens 11 and the imaging lens group 14 are
This constitutes a projection means.

Further, the tungsten lamp 22, the light shielding plate 23, the projection lens 24, and the semi-transparent mirror 25 (reflecting the light beam) constitute a third projection means.

With the above configuration, when the lamps 1, 22 and 29 are turned on and the television set is driven, the cathode ray tube 20
The fundus image and the image of the index light source are projected above.

That is, only the infrared rays of the radiation from the tungsten lamp 1 pass through the filter 21 and are converged onto the ring slit 6 by the converging action of the condenser lenses 2 and 3 and the reflecting action of the mirror. Further, the infrared light flux that has passed through the ring-shaped aperture forms a ring aperture image almost on the mirror surface of the perforated mirror 9 due to the action of the relay lenses 7 and 8, and is then reflected there and is reflected by the objective lens 11 into the pupil or the pupil of the eye E. An aperture image is again formed near the cornea, and then the fundus is uniformly illuminated.

The object light emitted from the illuminated fundus exits the subject's eye, forms an image with the objective lens 11, passes through the diaphragm 10, is converged on the imaging lens group 14, passes through the semi-transparent mirror 25, and forms a flip-up mirror. 15 and forms a fundus image on the field lens 16, then the semi-transparent mirror 17
The light is reflected by the image pickup lens 18 and forms an image on the light-receiving surface of the image pickup tube 19 . Therefore, a fundus image is displayed on the cathode ray tube 20, but if the image is blurred, the focus is adjusted, for example, by slightly moving the imaging lens group 14 in the optical axis direction.

The light flux emitted from the aperture 23 illuminated by the lamp 22 is converged by the projection lens 24, enters the semi-transparent mirror 25, where part of it is transmitted, and the rest is reflected.

The transmitted light beam converges on the concave mirror 26, is reflected by the mirror surface, is further reflected by the semi-transparent mirror 25, and is transferred to the imaging lens group 1.
After passing through the aperture 10, the light is converged and enters the objective lens 11, where it is converged to form images of the index light sources 22 and 23 on the fundus E of the subject's eye, so that the subject can see the index. Visualize the light source. The remaining luminous flux is reflected by the semi-transparent mirror 25, then reflected by the flip-up mirror 15 to form an image in the vicinity of the field lens 16, then reflected by the semi-transparent mirror 17, and then sent by the imaging lens 18 to the light receiving surface of the imaging tube 19 as an index light source. Connect images 22 and 23. In that case, the position occupied by the light source image projected onto the fundus E and the position of the index light source image appearing on the fundus image displayed on the cathode ray tube exactly match.

Next, the light beams emitted from the fixation light sources 28 and 29 are converged by the imaging lens 27, and then pass through the semi-transparent mirror 17.
The image is formed on the image plane of the field lens, and the flip-up mirror 1
5, passes through the semi-transparent mirror 25, and enters the imaging lens 1.
4. Fundus E via aperture 10 and objective lens 11
An image of the fixation light source is formed.

The position of this fixation light source is appropriately set, for example, on the optical axis, and the subject is made to stare at the fixation light source to fix his/her line of sight, and then the index light sources 22 and 23 are illuminated from outside the visual field with light corresponding to the fixation point. Move toward the axis, ask the patient to notify you when the index image is visible, and stop the index light source at that position. At this time, since the index image is displayed together with the fundus image on the monitor, it is possible to know where on the fundus image the index image is stationary.

Therefore, by dividing the entire circumference of the visual field into equal parts around the fixation point and repeating the above operations, it is possible to almost separate the areas sensitive to light and the areas not sensitive to light on the retina.

Furthermore, when the flip-up mirror 15 is raised while the index image remains stationary, and the strobe tube 3 emits light, the photoreceptor placed on the image plane 30 is exposed to the fundus-reflected light, and at the same time,
Since the light beam from the index light source reflected by the semi-transparent mirror 25 also forms an image on the photoreceptor, the index image is also photographed on the developed photoreceptor together with the fundus image.

It is also possible to move the infrared filter 21 in front of the strobe tube 3 and use an infrared film as the photoreceptor.

FIG. 6 shows another embodiment, in which the fixation target as well as the moving index can be observed.

Fundus cameras numbered 1 to 21 in the figure are the same as those in FIG. 1. Further, an index light source consisting of a tungsten lamp 31 and a light shielding plate 32 provided with an index aperture is movable within the arrangement plane, 33 is a semi-transparent mirror, 34 is a projection lens, and 35 is a concave mirror, which forms an image with the light shielding plate 32. The image plane 30 of the lens group is mutually intersecting with respect to the semi-transparent mirror 33, and the image plane 30 of the lens group is parallel to the semi-transparent mirror 33.
are mutually exclusive with respect to the projection lens 34. that time,
Among the light beams emitted from the index light source, the light beams reflected by the semi-transparent mirror 33 are converged by the imaging lens group 14 and are focused at the aperture 1.
After passing through 0, the image is formed once, and then the objective lens 11
The image is re-imaged on the fundus E by . On the other hand, the light beam transmitted through the semi-transparent mirror 33 is transmitted to the concave mirror 3 by the projection lens 34.
5, is reflected there, enters the projection lens 34 from the opposite direction and is converged, is reflected by the semi-transparent mirror 33, is further reflected by the flip-up mirror 15, and enters the vicinity of the field lens 16. Form an image. However, this light beam forms an image on the image plane 30 when the flip-up mirror 15 is flipped up.

The light beam that has passed through the field lens 16 passes through the semi-transparent mirror 36 and is reflected by the semi-transparent mirror 17, and then forms an image on the imaging surface of the imaging tube 19 by the imaging lens 18.

This image formation position corresponds to the position where the light beam reflected by the semi-transparent mirror 33 forms an image on the fundus, and appears on the fundus image.

37 is a diffuser plate, 38 is a lamp, and this lamp illuminates the diffuser plate. The diffused light emitted from the diffuser plate 37 is reflected by the semi-transparent mirror 36 and then passes through the field lens 16.
The light is reflected by the flip-up mirror 15, passes through the semi-transparent mirror 33, passes through the imaging lens group 14, the diaphragm 10, and the objective lens 11, and illuminates the fundus with uniform brightness. This is a means for providing appropriate background brightness for the moving index, and the brightness is variable as necessary.

40 is a light-shielding plate having a minute aperture, and 41 is a lamp, both of which constitute a fixation light source. In addition, 39 is a projection lens, and the image of the fixation light source is transferred to the field lens 16.
As a result of being projected onto the upper image plane, the projected light flux reverses the observation and photographing system and forms an image on the fundus E. However, this luminous flux is a luminous flux that has passed through the semi-transparent mirror 17, and the semi-transparent mirror 17
The reflected light beam forms an image on the concave mirror 42, is reflected there, passes through the semi-transparent mirror 17, and is imaged on the imaging surface of the imaging tube 19 by the imaging lens 18.

With the above configuration, the lamps 31, 38 and 41 are turned on, and the fixation light source 40 in the background of a predetermined brightness,
By moving 41, the examinee's line of sight is guided in a desired direction and fixed. At this time, the selected part of the fundus is displayed on the monitor, and the fixation light source image also appears.

With the subject gazing at the fixation light source, measure index 3.
1 and 32 and give a signal when the indicator crosses the boundary between the visible position and the invisible position, the visual field range can be detected. At this time, the index image can be observed on the monitor, superimposed on the fundus image, and the fundus image and index image can be photographed together, or only the index image can be photographed.
Note that the apparatus for illuminating the fundus with invisible light and converting the fundus image into a visible image using the imaging means includes a background illumination means 37,
38 is convenient because the brightness of the background can be accurately determined independently of the intensity of the fundus illumination light amount.

FIGS. 7 and 8 are partial cross-sectional views of the embodiment shown in FIG. 6, in which essential parts are modified. First, the semi-transparent mirror 17, imaging lens 18, imaging tube 19, etc. in FIG. 7 correspond to the semi-transparent mirror, imaging lens, imaging tube 19, etc. in FIG. In this partial modification, instead of the concave mirror 42 shown in FIG.
4 is provided, and the concave mirror 42 of the embodiment shown in FIG.
A light shielding plate 43 and a lamp 44 are interlocked with the fixation light sources 40 and 41 so as to have the same effect as the light beam reflected by the light beam. Therefore, the light beam emitted from the fixation light source passes through the semi-transparent mirror 17 and heads toward the fundus, but the light beam emitted from the aperture of the light-shielding plate 43 illuminated by the lamp 44 passes through the semi-transparent mirror 1.
7, and the image pickup tube 19 is taken by the photographing lens 18.
Focus the aperture image on top.

Next, the flip-up mirror 15, semi-transparent mirror 33, etc. in FIG. 8 correspond to the flip-up mirror, etc. in FIG. 6. Here, an auxiliary light source consisting of a lamp 45 and a light shielding plate 46 having a minute aperture is interlocked with the index light source so as to have the same effect as the light beam reflected by the concave mirror 35 in FIG. That is, the index composed of the lamp 45 and the light shielding plate 46 is optically conjugate with the index composed of the lamp 31 and the light shielding plate 32. The light beam emitted from the auxiliary light source is converged by the projection lens 34, sequentially reflected by the semi-transparent mirror 33 and flip-up mirror 15, and then directed to the image pickup tube to produce a fundus image corresponding to the part on the fundus where the index light source forms an image. An auxiliary light source image is formed on the upper part.

FIG. 9 shows another embodiment. However, the same numbers are given to the same members as in the previously described embodiments. Further, an index light source consisting of a lamp 51 and a light shielding plate 52 provided with a minute aperture is movable within a plane perpendicular to the optical axis.
A projection lens 53 converts the light beam emitted from the index light source into a semi-transparent mirror 5.
4 and forms an image on the field lens 16 (image plane of the imaging lens group 14).

This imaging light beam is reflected by the flip-up mirror 15, passes through the imaging lens group 14, the diaphragm 10, and the objective lens 11, and forms an image on the fundus E, where it is visually recognized by the subject.

On the other hand, the index light beam that has passed through the semi-transparent mirror 54 forms an image on the concave mirror 55, is reflected there, returns to the optical path, is reflected by the semi-transparent mirror 54, is reflected by the semi-transparent mirror 17, and is directed onto the imaging tube 19 by the imaging lens 18. image is formed. Therefore, visual field detection can be performed by moving the index light sources 51 and 52. Note that the action of the fixation light source 40 and 41 is the same as described above, and will therefore be omitted. Further, in the embodiment, the functions of the index light source for visual field measurement and the fixation light source may be exchanged with each other.

The embodiment shown in FIG. 10 shows the main part when a part of the embodiment shown in FIG. 9 is modified. Here, semi-transparent mirror 1
7 or the image pickup tube 19 corresponds to that shown in FIG. 9, and an auxiliary light source consisting of a lamp 44 and a light shielding plate 43 is provided in place of the concave mirror 42 in FIG. be linked in relation to

In addition, an auxiliary light source consisting of a lamp 62 and a light shielding plate 63 is provided in place of the concave mirror 55 shown in FIG.
1 and 52 in a predetermined relationship.

Therefore, the light beams emitted from the index light sources 51 and 52 are reflected by the semi-transparent mirror 54 and directed toward the fundus of the eye, and are then emitted by the auxiliary light sources 62 and 6.
The light beam emitted by the light beam 3 is reflected from the opposite direction by the semi-transparent mirror 54 and heads toward the image pickup tube. Furthermore, the light beams emitted from the fixation light sources 40 and 41 pass through the semi-transparent mirror 17 and are directed toward the fundus, and the light beams emitted from the auxiliary light sources 43 and 44 pass through the semi-transparent mirror 17 and head toward the imaging tube. Images of each auxiliary light source are formed at respective positions on the fundus image corresponding to the positions of the index or fixation light source image formed on the fundus.

FIG. 11 shows another embodiment. 1 to 2 in the diagram
0 members are the same as those in the previously described embodiments, and these constitute the optometrist. Note that the image pickup tube 19 of this embodiment uses a normal vision sensor having sensitivity in the visible range.

Next, a lamp 71 and a light shielding plate 72 having a minute aperture are provided.
73 constitutes an index light source, 73 is a projection lens, and 74 is a thin semi-transparent mirror, which is installed obliquely with respect to the optical axis of the observation photographing system. 7 is a concave mirror, which is gimbaled (cardan) so that it can rotate around its center of curvature.
It shall be supported by a mechanism, etc. Further, a minute opening 75a is provided, for example, in the center of the concave mirror 7, as shown in FIG. 12, and a lamp 76 that swings together with the concave mirror is arranged behind this minute opening. lamp 7
6 and the minute aperture 75a constitute a fixation light source.

At this time, the concave mirror 75 is provided in conjunction with the image plane 30 of the imaging lens group 14 with respect to the semi-transparent mirror 74, and as a result of providing the index light sources 71, 77 and the concave mirror 75 in conjunction with the projection lens 73, the light beam emitted from the index light source The light beam that has passed through the semi-transparent mirror 74 once passes through the concave mirror 75.
After the image is formed on top, it is reflected there, and then the semi-transparent mirror 7
Reflected on the back surface of 4, imaging lens group 14, diaphragm 10
The image is then formed on the fundus E through the objective lens 11. On the other hand, among the light beams emitted from the index light source, the light beams reflected by the semi-transparent mirror 74 are reflected by the oblique mirror 15, form an image on the field lens 16, are reflected by the semi-transparent mirror 17, and are sent to the imaging tube 19 by the imaging lens 18. The image is formed on the light receiving surface.

Next, the light beams emitted from the fixation light sources 75a and 76 are reflected by the semi-transparent mirror 74, and converged by the imaging lens group 14,
After passing through the aperture 10, an image is formed once, and then an image is formed on the fundus E by the action of the objective lens 11.

The background illumination means consisting of a lamp 77 and a diffuser plate 78 includes a semi-transparent mirror 17, a field lens 16, and an oblique mirror 1.
5. The fundus E is illuminated to a predetermined brightness through the semi-transparent mirror 74, the imaging lens group 14, the diaphragm 10, and the objective lens 11.

Incidentally, if the semi-transparent mirror 17 is arranged at a reverse inclination and modified so that the image plane on the field lens is observed through the eyepiece lens, observation with the naked eye can be performed.

The operation of the above embodiment will be explained. lamps 1, 7
When lights 1, 76 and 77 are turned on and the television set is driven, an image of the index light source is displayed on the cathode ray tube 20 together with the fundus image. The operator uses the fixation light source 75
a, 76 is adjusted to fix the subject's line of sight at a desired position, and then the index light sources 71, 72 are moved to measure the visual field. The relationship between this field of view and the fundus can be known from the image displayed on the cathode ray tube, but by placing a film at the image plane 30 and moving the oblique mirror 15 out of the optical path just before the strobe tube 3 emits light, the fundus is reflected. The film is exposed to the light and the index light flux reflected by the semi-transparent mirror 74, and a display image showing the projected position of the index together with the fundus of the eye is photographed.

As is clear from the effects of the embodiments of the present invention described above, information regarding the visual field is clearly displayed together with the fundus image without using a high-intensity light source as an index light source, so that the results of perimetry can be determined based on which part of the fundus and the actual field. This has the effect of letting you know if it is compatible. In other words, when attempting to observe and photograph an index image projected onto the fundus of the eye, it is impossible to observe and photograph the index image unless the intensity of the index light source is increased, and on the other hand, increasing the intensity of the index light source causes miosis of the subject's eye. Although a problem arises, according to the present invention, the intensity of the index light source can be made weak, and the concomitant pupil miosis of the subject's eye will not occur.

In addition, since the detected information can be photographed together with the fundus of the eye and an accurate record can be left, it is extremely effective in diagnosing diseases and the like.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention, Fig. 2
The figure is a plan view of a ring slit plate, FIG. 3 is a plan view of a perforated mirror, FIGS. 4 and 5 are plan views of a light shielding plate, respectively, FIG. 7
8 and 8 are partial sectional views showing a modified portion of the embodiment shown in FIG. 6, FIG. 9 is a vertical sectional view showing another embodiment, and FIG. 10 is a main part of a modification of the embodiment shown in FIG. 9. FIG. 11 is a longitudinal sectional view showing another embodiment, and FIG. 12 is a plan view of a concave mirror having a minute aperture. In the figure, 21, 31, 51 are lamps for index light sources, 23, 32, 52 are light shielding plates with minute apertures, 25, 33, 54 are thin semi-transparent mirrors, 26, 3
5 and 55 are concave mirrors, and 29 and 41 are lamps for fixation light sources.

Claims (1)

[Scope of Claims] 1. A first projection means for projecting an index for visual field measurement onto the fundus of the eye to be examined, a second projection means for projecting the fundus of the eye to be examined onto a predetermined observation plane or photographing plane, and an optical connection between the index and the same. an index conjugate to the observation plane or the photographing plane at a position where the index image on the fundus by the first projection means is to be formed again by the second projection means without passing through the eye to be examined; An ophthalmological apparatus characterized by having a third projection means for projecting images onto the ophthalmologic apparatus. 2. The ophthalmologic apparatus according to claim 1, wherein the index is movable within a predetermined plane. 3 an index light beam directed to the first projection means;
The ophthalmologic apparatus according to claim 1, wherein the index light beam directed to the projection means is split by the light splitting means.