JPS633612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmic surgery microscope having a function of measuring the corneal shape of an eye to be examined and a function of measuring the refractive power of the eye to be examined.

The eye forms a precise optical system, and appropriate measures are taken to restore its function in the event of any disease. Particularly when some kind of surgery is performed on the eyeball, it is important to reconstruct its function and shape, and recovery of the eye's refractive power is an important factor that determines the success or failure of the surgery. In recent years, with the aging of the population, anterior segment surgery, especially cataract surgery, has become more common, but it is difficult to accurately assess changes in corneal shape due to surgery and changes in eye refractive power due to intraocular lens insertion. This is an indispensable thing. For this reason, it is necessary to constantly measure changes in the shape of the cornea and the refractive power of the eye, not only after the surgery, but also during the surgery, in order to know whether or not the restoration process is normal. Traditionally, the surgical microscopes used to perform this type of eye surgery only have the observation and photography function during surgery, and a completely different method is required to measure the corneal shape and refractive state of the eye during surgery. The procedure must be replaced with a new measuring device, which requires a long interruption of the surgery, requires considerable effort, and the layout makes it practically impossible to perform the procedure using a full-scale measuring device.

The purpose of the present invention is to provide a surgical microscope with a function to measure the corneal shape and eye refractive power, so that if necessary, the eye can be immediately examined and the surgical condition can be checked while proceeding with the surgery. That is.

According to the present invention, alignment of the eye refractive power measurement system or the corneal topography measurement system of the eye to be examined and the eye to be examined can be performed by microscopic observation, and furthermore, the corneal reflection image of the projection index of the corneal topography measurement system can be aligned. There is no need to specifically provide an alignment means in the eye refractive power measurement system or the eye corneal shape measurement system. Examples of the present invention will be described below.

In FIG. 1, light from a lamp 1 for observing the anterior segment of the eye to be examined passes through a half mirror 2, a condenser lens 3, a prism 4 with a lens, and an objective lens 5 to illuminate the eye Ep. The light reflected from the anterior segment of the subject's eye is passed through an objective lens 5, a beam splitter 13,
14 and enters the relay lens groups 6, 7, 8,
After being reflected by the flip-up mirror 9, it is observed by the viewing eye E via the fixed mirror 10 and the eyepiece lens 11.

When photographing the anterior segment of the subject's eye, the strobe 113 emits light and illuminates the anterior segment through the objective lens 5, and the light from the anterior segment passes through the objective lens 5, beam splitters 13, 14, relay lens group 6, The image passes through mirrors 7 and 8, passes under the mirror 9 that has been flipped up, and is imprinted on a film or other image recording means 12.

Here, the optical system for measuring eye refractive power will be explained.

Light from a light source 20 for measuring eye refractive power passes through a condenser lens 19 and illuminates the projection chart 18 . The projection chart 18 has slits 18a, 18 having at least three directions as shown in FIG.
b, 18c, and the light passing through each slit is
Projection lens 29, ring-shaped aperture 2 shown in FIG.
8a aperture diaphragm 28, relay lens 27,
17, the light passes through the perforated mirror 16, the relay lens 15, the beam splitters 14 and 13, and the objective lens 5, and reaches the eye Ep to be examined, and projects each slit image light onto the fundus of the eye.

The light reflected from the fundus passes through the objective lens 5, beam splitters 13 and 14 again, and reaches the relay lens 1.
5. Hole of perforated mirror 16, relay lens 2
1, 37, an aperture stop 38 having an aperture 38a as shown in FIG. 4, and a projection lens 39 before reaching the light receiving chart 22. The light receiving chart 22 is conjugate with the projection chart 18 with respect to the perforated mirror 16, and is connected to the three slits 18a, 18 of the projection chart 18.
There are three slits 22a, 22b, 22c as shown in FIG.
Light receiving elements 23a, 23b, placed at the rear of c.
23c. The best focusing plane for each slit (at this time, the received light output is maximum) is found by moving the lens systems La and Lb along the optical axis, and the amount of movement from the initial position is determined based on the amount of movement from the initial position.
The refractive power of Ep is calculated. Here, the refractive power of the eye to be examined corresponding to each slit direction is calculated and the spherical refractive power S, astigmatic degree C, and astigmatic axis angle A are calculated.
Calculate. Next, the corneal shape measuring optical system will be explained. Light sources 34a, 34b,..., 34i, 34
The light from j is directed to the corresponding light guides 33a, 33
b, . . . , 33i, 33j, and become light sources 32a, 32b, . The light reflected by the cornea emerges as if from the corneal reflected image,
The objective lens 5, beam splitter 13, and projection lens 35 form an image onto a two-dimensional solid-state image sensor 36.

If the light sources 32a, 32b,..., 32j are arranged concentrically around the objective lens 5 as shown in FIG. is projected. The curve of the cornea is calculated from this projected image. In other words, a ring-shaped projection chart is projected onto the eye to be examined, and if the eye to be examined does not have astigmatism, the corneal reflection image will also be a perfect circle, but if there is astigmatism, it will become an ellipse, and if there is irregular astigmatism, distortion will be added to this image. The shape of the corneal reflection image is determined using a solid-state image sensor, and the corneal curvature R, degree of astigmatism D, and astigmatism axis angle A are calculated from the detection results. In addition to a two-dimensional CCD, the solid-state image sensor has three one-dimensional CCDs arranged radially or in parallel, and detects the coordinates of the intersection with the corneal reflection image, or the height or diameter from a predetermined point to the intersection. It may be something you do. As an example of identifying the corneal reflection image,
General 2 from the obtained intersection coordinates of at least 5 points
The following curve formula ax ² +b×Y+cY ² +dx+eY+1=0
Solve to calculate coefficients a to e.

The refractive power and corneal shape of the eye to be examined determined in the above manner are displayed on the image display element 24, for example, on the seventh screen.
The image is displayed as shown in the figure and is observed or photographed through a lens 25, a mirror 26, and an observation or photographing optical system.

The above is an example of a surgical microscope that has both a refractive power measurement function and a corneal shape measurement function, but the following replacements are also possible. That is, regarding the beam splitters 13 and 14, the eighth
As shown in the figure, wavelengths are separated using spectral characteristics (the horizontal axis is the wavelength λ and the vertical axis is the transmittance T), and a wavelength shorter than characteristic 13a is used to observe or photograph the anterior segment of the eye. A wavelength longer than 13b may be used, or the beam splitter 13,1
4 may be used as a flip-up mirror and moved out of the optical path except during measurement. In addition, as a means of separating light for observation photography and measurement, it is also possible to separate the light for observation and photography by changing the frequencies of the light sources. It is also possible to use a ring-shaped line light source instead of the light sources 32a, 32b, . . . , 32j, or to arrange the light emitting elements themselves.

On the other hand, it goes without saying that an image pickup tube or the like can be used as a recording means to connect to video recording. That is, for example, the mirror 10 in FIG. 1 may be replaced with a half mirror, and the light flux passing through this may be guided to the imaging tube. Fig. 9 shows an example of the arrangement of a light source that projects onto the cornea of the eye to be examined. When observing or photographing the eye Ep to be examined, the light source is located near the objective lens 5 or near the optical axis as shown in 41a, and the shape of the cornea is measured. In this case, it can be switched or moved away from the objective lens 5 or the optical axis, as shown in 41'a. As shown in FIG.
a, . . . move to positions 41'a, 42'a, 43'a, . As a result, it is located near the objective lens except when measuring the corneal shape, ensuring a space between the objective lens and the eye to be examined, making it easier to perform ophthalmic surgery.

Note that these multiple light sources 41a, 42a, 43
The above-mentioned effect will be enhanced if the lenses a, .
Further, the plurality of light sources 41a, 42a, 43a,
By moving, etc., the diameter of the so-called ring-shaped chart changes, and the corneal shape at various heights of the eye to be examined can be measured.

FIG. 11 shows another example of the arrangement of light sources for corneal shape measurement, in which a plurality of rows are arranged concentrically with respect to the objective lens or the optical axis. Each ring-shaped light source moves concentrically as shown in FIG.
That is, 51a is 51'a, 51b is 51'b,
..., 52a is 52'a, 52b is 5
It can move like 2'b.

Multiple concentric ring-shaped indicators are placed on the eye to be examined.
By projecting, it is possible to determine the shape of the cornea at various heights relative to the axis of the eye to be examined. Note that, instead of moving in the direction perpendicular to the optical axis, that is, in the peripheral direction, the same effect can be achieved by moving it along the optical axis, that is, in the direction of the eye to be examined.

FIG. 13 shows an embodiment in which a corneal reflection image of a light source projected toward the cornea is used for alignment for corneal shape measurement and eye refractive power measurement in order to measure the corneal shape of the eye to be examined. The corneal reflected light from the light source 32a passes through the objective lens 5 and the beam splitter 13 and is observed by the observing eye E. At this time, an alignment chart 60 is provided at a position conjugate with the focal plane of the observing eye E. This chart has a ring-shaped opening 60a as shown in FIG.
When observed with
Since the corneal reflection images 32'a, 32'b, . . . , 32'j of the light sources 32a, 32b, . Then perform alignment.

FIG. 16 shows the optical arrangement of each functional part of a surgical microscope having the functions of illumination, observation photography, refractive power measurement, and corneal shape measurement. Pa indicates illumination, Pb indicates observation/photography, Pc indicates refractive power measurement, and Pd indicates corneal topography measurement system. Here, reference numerals 14 and 14' denote beam splitters, which may simply split the luminous flux or split based on the wavelength. It may also be a flip-up mirror.

FIG. 17 shows which part of the luminous flux is used to perform each function, and Pa to Pd are based on the above classification. Here too, the prism 41 and the beam splitter 14 may be replaced with mirrors, wavelength splitting mirrors, etc., respectively.

FIGS. 18A to 18E show other examples of division and how to take the luminous flux with respect to the objective lens 5. Note that other combinations may also be used.

The ones shown in Figs. 19 and 20 are examples in which the indicators for corneal shape measurement are removable, and each ring indicator l ₁
~l ₃ is the lamp 79a, 79b,..., 79i, 79
j, and is arranged as one detachable unit 80 to be detachably attached to an objective lens frame 81.

As explained above, according to the present invention, by adding the corneal shape measurement function and the refractive power measurement function, it is possible to easily observe the progress and condition of the surgery even during the surgery, so that the progress and condition of the surgery can be accurately observed. It is possible to judge whether the device is good or bad, and this can be reflected in the surgery. Furthermore, according to the present invention, when observing the anterior segment of the eye, which is the surgical site, during surgery by changing the magnification of the relay lens group as is well known, the eye refractive power measurement system does not use the relay lens group, so that the anterior segment of the eye, which is the surgical site, is observed. The spatial separation between the incident and exit areas of the index light beam at the ophthalmoscope is stabilized regardless of the magnification change, and the measurement accuracy is guaranteed because harmful light from the anterior segment of the eye is not mixed into the index light beam reflected from the fundus. In addition, the position of the index image relative to the macula on the fundus surface does not change as the magnification changes, allowing stable measurement. Furthermore, since the relay lens group is not used in the corneal shape measurement system, the measurement results are stable for the same eye to be examined regardless of the magnification change, and measurement accuracy is guaranteed. Since the objective lens is shared, the apparatus can be made more compact, and the working distance from the eye to be examined can be increased compared to when a half mirror is interposed in front of the objective lens. Further, the means for measuring the eye refractive power and the means for measuring the corneal shape can be aligned using a microscope optical system for observing the anterior segment of the eye to be examined.

[Brief explanation of the drawing]

Fig. 1 is a diagram of an embodiment of the present invention, Fig. 2 is a projection chart of the eye refraction measurement system, and Figs. 3 and 4 are the aperture diaphragms on the light emitting side and light receiving side of the eye refraction measurement system, respectively. Figure 5 is a diagram of the light reception chart of the eye refraction measuring system.
Figure 6 is a diagram of the arrangement of the light source of the corneal topography measurement system, Figure 7 is an explanatory diagram of the image display element that displays the measurement data of refractive power and corneal shape, and Figure 8 shows the wavelength of the observation and photographing optical system and measurement optical system. Figures 9 and 10 are diagrams of spectral transmittance characteristics when separated by
Fig. 12 is a diagram of an embodiment in which multiple rows of light sources of the corneal shape measurement system are arranged and movable, Fig. 13 is a diagram of an embodiment in which a corneal reflection image of the light source for measuring the corneal shape is used for alignment, and Fig. 14 The figure is a diagram of a ring-shaped chart provided in the observation optical path of the microscope and serves as a reference for alignment. 18A to 18E, FIG. 19, and FIG. 20 are diagrams of embodiments in which the corneal shape measurement index is removable. In the figure, Ep is the eye to be examined.
E is an observation eye, La and Lb are lens systems, 1 is a lamp for observing the anterior segment of the eye, 4 is a prism with a lens, 5 is an objective lens, 9 is a flip-up mirror, 11 is an eyepiece, 12 is an image recording means, 18 is a projection chart for measuring eye refractive power; 18a, 18b, 18c are slits; 20 is a light source for measuring eye refractive power; 24 is an image display element; 28, 38 are aperture stops; 22 is a light receiving chart; 23a, 23b , 23c are light receiving elements, 32a, 32b, .

Claims (1)

[Scope of Claims] 1. A means for illuminating the anterior segment of the subject's eye, a microscope optical system for observing the illuminated anterior segment of the subject's eye through an objective lens and a relay lens group, and the objective lens and the relay. Among the lens groups, only the objective lens is used in common to project a first index light flux onto the fundus of the subject's eye via a first light flux regulating means, and to reflect light of the index light flux from the fundus of the subject's eye into a second a means for measuring eye refractive power by receiving light through a light flux regulating means; and a means for projecting a second index light flux onto the cornea of the eye to be examined and sharing only the objective lens among the objective lens and the relay lens group; An ophthalmic surgery microscope characterized by having means for measuring the corneal shape by receiving the corneal reflected light of the second index light beam. 2. The ophthalmic surgical microscope according to claim 1, wherein the second indicator is movable in a peripheral direction or in an optical axis direction with respect to the optical axis of the microscope optical system. 3. The ophthalmic surgical microscope according to claim 1, wherein at least the light beam incident on the microscope optical system and the light beam involved in the means for measuring the eye refractive power pass through different areas in the objective optical system.