JPS6325777B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmic surgical microscope, in particular an ophthalmic surgical microscope combined with a keratometer.

In the past, when corneal surgery was performed, corneal astigmatism often occurred after the surgery.

The reason for this is thought to be that the cornea is deformed when stitching around the corneal periphery during surgery. Therefore, there is a demand for measuring the degree of corneal deformation during surgery, and recently a corneal shape measuring instrument that can be inserted into and removed from the optical path of a surgical microscope has been commercialized.

In this method of use, the measurement optical system is inserted into the microscope optical path only when measuring the corneal shape, but since the microscope optical system and the measurement optical system are coaxial, if the surgical site is deviated from the center of the cornea, The optical axis of the microscope optical system is shifted from the eye to be examined, and when attempting to measure the corneal shape, the microscope must be moved until the optical axis matches the axis of the eye to be examined, resulting in poor operability. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an ophthalmic surgical microscope which eliminates the drawbacks of the conventional microscope. The purpose of this is to provide a light splitting means between the microscope objective lens and the cornea of the eye to be measured in the optical path, set the corneal shape measuring optical path through the means, and keep the measuring optical path covered regardless of the movement of the microscope. This is accomplished by turning the optometric cornea toward the center. Here, the alignment between the keratometer and the eye to be examined is performed by projecting the alignment index of the keratometer onto the eye to be examined and observing it with a microscope. This is possible even if the microscope is shifted relative to the eye to be examined, as long as it is within the field of view of the microscope. That is, in the present invention, the microscope has both the functions of observing the anterior segment of the eye and positioning the keratometer with respect to the eye to be examined.

Using the present invention, conventionally the microscope had to have a special structure to attach the measuring instrument, but there is no need to be limited to this, and the microscope and keratometer can be integrated into the eye to be examined. Even when the eye is relatively moved, the corneal shape of the eye to be examined can always be measured.

Examples of the present invention will be described below. 1 in Figure 1
is a surgical microscope objective barrel, 2 is an automatic keratometer, 3 is an arm fixed to the microscope, 4 is an X-Y stage, 5 is a rotatable support that suspends the automatic keratometer 2, and 6 is a total reflection mirror. , 7 is a half mirror. Further, 8 is a ring-shaped projection index image for optical axis alignment, which is set coaxially with the measurement optical axis of the keratometer. 9 is an eye to be examined, and 10 is a measurement button.

Except when measuring the corneal shape, the automatic keratometer 2 is rotated around the support 5 to keep the half mirror 7 out of the field of view of the microscope. When measuring the shape of the cornea, after bringing the half mirror 7 into the field of view, while observing through the half mirror 7 with a microscope so that the center of the projection index image 8 for optical axis alignment coincides with the center of the cornea of the eye 9 to be examined. , move X-Y stage 4. After the center of the projection target image 8 for optical axis alignment coincides with the center of the cornea, the measurement button 10 is pressed to measure the corneal shape. The automatic keratometer 2 is attached to a part of the microscope main body so that the optimum measurement surface coincides with the field focus plane of the microscope. When the surgical site is shifted from the center of the cornea, the microscope and arm 3 move in parallel, resulting in automatic keratometer 2 for the eye being examined.
The relative position of changes.

In this case, while looking at the microscope,
is moved so that the center of the projection target image 8 for optical axis alignment coincides with the center of the cornea. That is, the total reflection mirror 6 and the half mirror 7 are integrally translated in the X direction and the Y direction to align the measurement optical axis with the eye axis of the subject. During such adjustments, even if the half mirror 7 moves, light still passes through the microscope, so the field of view of the microscope changes.
Not affected. In addition, in the above explanation, it is assumed that the total reflection mirror 6 and the half mirror 7 are integrally translated, but the half mirror 7
It is also possible to perform translational displacement only.

FIG. 2 shows an example of a corneal topography measuring device.

101 is an annular light source, 102 is a corneal-shaped objective lens, 103 is a half mirror that reflects visible light and transmits infrared light, 104 is an alignment chart, 105 is a chart illumination light source, and 106 is a position detector installed radially. It has been done. Note that in addition to the position detector, an image sensor such as a CCD may be used. The light from the alignment chart 104 illuminated by the chart illumination light source 105 is reflected by the half mirror 103, and then projects an index onto the cornea of the eye to be examined by the objective lens 102. After the positioning using the microscope is completed, the annular light source 101
emits light instantaneously to form a ring image of the annular light source 101 on the cornea of the eye to be examined.

Then, the ring image on the cornea passes through a half mirror 103 and is formed on a position detector 106 by the objective lens 102 . If there are at least five position detectors 106, the general quadratic curve equation AX ² +
The elliptical shape of the corneal reflection image can be determined by solving BXY+CY ² +DX+EY+1=0, and the corneal shape can be calculated from this.

FIG. 3 shows a second embodiment of the present invention in which the optical axis is aligned by moving a part of the optical system of the keratometer. In the drawings, members with the same symbols as in FIG. 1 indicate the same members.

In FIG. 3, 11 is an arm fixed to the keratometer, and 12 is a fulcrum of a mirror at the tip of the arm. The fulcrum 12 supports the vicinity of the center of the surface of the total reflection mirror 6, and the total reflection mirror 6 can swing in all directions around the fulcrum 12.

Unlike the embodiment shown in FIG. 1, in this embodiment the automatic keratometer 2 is fixed to the arm 3 from the microscope and is always integrated. During surgery, if the microscope moves and the center of the projection index image 8 for optical axis alignment no longer matches the center of the cornea, the total reflection mirror 6 is rotated while observing the microscope through the half mirror 7 to align the optical axis. The center of the projection target image 8 is made to coincide with the center of the cornea. This total reflection mirror 6 is moved from the fulcrum 1 so that it stays at that position when you release your hand.
Add some friction to 2. After aligning the center of the projection index image 8 for optical axis alignment with the center of the cornea in this manner, the measurement button 10 is pressed to measure the corneal shape.

In addition to the total reflection mirror 6, the half mirror 7 may be movable.

In the embodiments shown in FIGS. 1 and 3, the positioning observation index is projected only during corneal measurement, and if the light is turned off so as not to generate a projected index image at times other than corneal measurement, a good microscope field of view can be obtained.

The wavelength characteristics of the half mirror 7 are the measurement light of the keratometer,
There are various possibilities depending on the type of projection index light for optical axis alignment, but if infrared light is used as the measurement light and visible light is used as the projection index light, the wavelength characteristics of the half mirror will be in the infrared region so that there is no loss of light intensity with respect to the measurement light. We need something that is reflective and has the characteristics of a half mirror in the visible range.

In addition, if the automatic keratometer has a built-in television camera that is sensitive to the infrared region and uses infrared light as the projection index light for optical axis alignment, and also performs positioning on the television monitor, the wavelength characteristics of the half mirror may be As such, we need something that reflects in the infrared region and has the characteristics of a half mirror in the visible region, that is, something that can be observed with a microscope using visible light. Note that what is described as a half mirror in the above explanation may be any light splitting means.

As described above, according to the present invention, a corneal shape measuring optical system is inserted between the objective lens and the cornea to be measured via a light splitting means such as a half mirror, and when the optical axis of the microscope and the center of the cornea of the eye to be examined are misaligned, Also, corneal topography can be measured without affecting the field of view of the microscope and without moving the microscope.

[Brief explanation of drawings]

Fig. 1 is a diagram of a first embodiment of the present invention, Fig. 2 is an explanatory diagram of a corneal topography measuring device, and Fig. 3 is a diagram of a second embodiment of the present invention. 2 is an automatic keratometer, 3 is an arm, 4 is an X-Y stage, 5 is a rotatable support, 6 is a total reflection mirror, 7 is a half mirror, 8 is a projection index image for optical axis alignment, 9 is a target optometry, 10 is a measurement button, 11 is an arm, 12 is a fulcrum, 101 is an annular light source, 102 is an objective lens,
104 is a positioning chart, 105 is a chart illumination light source, and 106 is a position detector.

Claims (1)

[Scope of Claims] 1. A light splitting means provided in an optical path between a microscope objective lens facing the eye to be examined and the cornea of the eye to be examined;
A measuring optical system is provided for projecting an index for corneal shape measurement onto the cornea of the eye to be examined in an optical path branched by the light splitting means, detecting a corneal reflection image of the index, and measuring the corneal shape, while the microscope body is fixed. a corneal shape measuring means that is movable so that the optical axis coincides with the axis of the eye to be examined; and a state of alignment of the corneal shape measuring means with respect to the eye to be examined can be observed by observing the index image and the anterior segment image of the eye to be examined. An ophthalmic surgery microscope, characterized in that it has an observation optical system including the microscope objective lens. 2. The measurement optical system includes a rotatable mirror,
The ophthalmic surgery microscope according to claim 1, wherein the measurement optical axis and the eye axis to be examined are made to coincide with each other by rotating the mirror. 3. The ophthalmic surgical microscope according to claim 1, wherein the index is projected onto the cornea of the eye to be examined only during corneal shape measurement.