JPS63267356A - Apparatus for laser medical treatment of cornea - Google Patents

Abstract

PURPOSE:To obtain a laser cornea medical treatment apparatus capable of making an incision depth variable at every area of the surface of the cornea using low output laser beam, by mounting a laser beam emitting means, a means for guiding the laser beam to the selected area of the cornea to incise the cornea and a means for regulating the quantity of the laser beam during irradiation. CONSTITUTION:The laser beam L emitted from a laser beam source 1 is incident to a galvano-mirror 3a while regulated in quantity by a variable attenuator 2 to allow deflection scanning on the galvano-mirror 3a. The laser beam L is further deflected on the cornea Ec in an incision direction by a trihedral mirror rotator 4 and subsequently condensed on the cornea Ec of an eye E to be examined through a condensing lens 5 to carve radial incision lines C in the cornea Ec. At this time, by regulating the scanning speed of the galvano- mirror 3a performing the deflection scanning with the laser beam L, the incision depth on the surface of the cornea Ec of the eye E to be examined can be made variable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laser angle correction device that shapes the cornea of the eye to be examined and corrects refraction by irradiating laser light such as an excimer laser. It is.

[Prior Art] In recent years, corneal refractive surgery involves irradiating the cornea of a test subject 1H with a laser beam such as an excimer laser, making radial incisions on the surface of the peripheral cornea, and measuring the curvature of the central part of the f61 model: It is being studied that A-sections occur. In this laser corneal treatment device, a slit-shaped opening is placed above the corner II of the eye to be examined, and the surgery is performed by irradiating the opening with a laser beam having a uniform intensity distribution. However, with the above-mentioned conventional devices, when making an incision on the surface of the peripheral cornea, the incision depth is uniform, and it is not possible to make incisions at different depths depending on the part of the cornea. Since the peripheral surface is incised by irradiating a laser beam onto a light-shielding plate with a slit-shaped opening, most of the energy of the laser beam is not used for incision, so a high-power laser light source must be used. There is a problem.

[Object of the Invention] An object of the present invention is to provide a laser corneal treatment device that eliminates the problems of the conventional method described above and can vary the incision depth for each part of the corneal surface using a low-power laser beam. be.

[Summary of the Invention] The gist of the present invention to achieve the above-mentioned object is to provide an apparatus for shaping and treating the cornea using laser light, which includes means for emitting laser light and guiding the laser light to a selected location on the cornea. This is a laser corneal treatment device characterized in that the means for incising the cornea and the means for adjusting the amount of laser light during irradiation are A410.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a first embodiment of the present invention, in which a laser light source 1
variable attenuator 2 along the optical path of the laser beam from
, galvanometer mirrors 3a, 3 driven by the scanner 3
A surface mirror rotator 4 and a condensing lens 5 are arranged. In addition, as the laser light, for example, excimer laser
Light is used, and the variable attenuator 2 has filters with different concentrations disposed in the circumferential direction, and by rotating this filter, the intensity of the transmitted laser beam can be adjusted. Further, the galvanometer mirror 3a deflects and scans the laser beam, and the three-sided mirror rotator 4 selects the direction of incision on the cornea Ec of the eye E to be examined.

In the laser corneal treatment device configured in this way,
The laser light emitted from the laser light source 1 is adjusted in light intensity by a variable attenuator 2, enters a galvanometer mirror 3a, and is deflected and scanned by the galvanometer mirror 3a. The laser beam is further transmitted to the cornea Ec by a three-sided mirror rotator 4.
After being deflected in the direction of the incision above, the light passes through the condenser lens 5 and is focused onto the cornea Ec of the eye E to be examined, thereby carving a radial incision line C on the cornea Ec as shown in FIG.

At this time, a galvanometer mirror that deflects and scans the laser beam
By adjusting the scanning speed of 3a, the depth of incision on the surface of the cornea Ec of the eye E to be examined can be made variable. That is, when the scanning speed is slowed down, a large amount of energy is applied to the same incision line C on the corneal surface, resulting in a deeper incision depth, and when the scanning speed is increased, only a small amount of energy is applied, resulting in a shallower incision depth. In addition, the incision depth can be made variable by adjusting the variable attenuator 2 and changing the amount of laser light for each part of the corneal surface.Furthermore, the laser light emitted from the laser light source 1 can be converted into pulsed laser light. , it is also possible to adjust the incision depth by changing the pulse interval. This is because when the pulse interval is short, a large amount of energy is supplied to the same incision line C on the corneal surface, resulting in a deep incision, and when the pulse interval is long, only a small amount of energy is supplied, resulting in a shallow incision depth. It's for a reason.

In the first embodiment described above, the galvanometer mirror 3a
A three-sided mirror rotator 4 is used to deflect and scan the laser beam two-dimensionally, but an acousto-optic optical deflector (AO
It is also possible to perform two-dimensional deflection scanning using a deflector (deflector). FIG. 3 shows a configuration diagram of a two-dimensional deflection means using an acousto-optic light deflector, in which the first acousto-optic light deflector 6. A lens 7 and a second acousto-optic light deflector 8 are arranged in sequence, and the acousto-optic light deflectors 6 and 8 are in a conjugate positional relationship with the lens 7. After the laser light is deflected by the acousto-optic deflector 6 in a direction parallel to the plane of the paper, it enters the second acousto-optic deflector 8 via the lens 7 and is deflected in the direction perpendicular to the plane of the paper. Therefore, by adjusting the degree of deflection of the acousto-optic light deflectors 6 and 8, it is possible to irradiate a two-dimensional arbitrary position with laser light.

Furthermore, instead of the condensing lens 5 in the first embodiment, an optical system combining two cylindrical lenses may be adopted. FIG. 4(a) is a block diagram of the optical system. (b)
is a side view of (a). The first cylindrical lens 9 is a lens 77' that focuses light only in the direction parallel to the page and not in the direction perpendicular to the page, and the second cylindrical lens 10 focuses light in the direction perpendicular to the page. It is a lens that focuses light only in the direction parallel to the paper surface, but not in the direction parallel to the paper surface. Also, the cylindrical lens 9.1
0 are arranged so as to focus on the same position. The shorter the focal length of the lens, the smaller the luminous flux can be narrowed down. Therefore, when a laser beam with a circular cross section enters an optical system consisting of cylindrical lenses 9 and 10, the focal point will have a long axis in the direction parallel to the plane of the paper. , and an elliptical laser spot light with a short axis perpendicular to the plane of the paper is formed. By using such an optical system, the examinee's eye E
It becomes possible to adjust the line width when cutting the incision line C on the surface of the cornea Ec, and it is possible to obtain an incision that looks like a cut with a thin blade, for example.

FIG. 5 shows a second embodiment, in which a two-dimensional ultrasonic deflector 11, a lens 12, and a first half mirror 13 that reflects only the laser beam wavelength are arranged along the optical path of the laser beam. A second half mirror 14, a lens 15, and a position sensor 16 are arranged in the retroreflection direction of the first half mirror 13.
The output of the position sensor 16 is connected to the two-dimensional ultrasonic deflector 11 via a deflector controller 17. Further, a lens 18 and an index light source 19 are arranged in the reflection direction of the second half mirror 14.

In the laser corneal treatment device configured in this way,
The laser light is reflected by the first half mirror 13 via the two-dimensional ultrasonic deflector 11 and the lens 12, and is focused on the cornea Ec of the eye E to perform the incision. The light beam is collimated by the lens 18, reflected by the second half mirror 14, and irradiated onto the cornea Ec via the first half mirror 13. The reflected light from the cornea Ec passes through the half mirrors 13 and 14 and enters the lens 15, and is condensed by the lens 15 and focused on the position sensor 16. The position signal from the zero position sensor 16 is sent to the deflector controller 17. Based on this position information, the deflector controller 17 controls the two-dimensional ultrasonic deflector 11 to deflect the laser beam two-dimensionally.

By doing this, even if the eye E to be examined moves during irradiation with laser light, the position sensor 16 will detect it, and if the two-dimensional ultrasonic deflector 11 is not corrected in accordance with the movement of the eye E, the laser beam will not move. The light can be irradiated to a predetermined position on the cornea Ec of the eye E to be examined, making it possible to continue the surgery safely and accurately. At the same time, two-dimensional ultrasonic deflector 1
By deflecting the laser beam two-dimensionally using 1, a radial incision line is carved on the peripheral surface of the cornea Ec of the eye E, and the incision depth can be made variable by appropriately setting the deflection scanning speed. can do.

[Effects of the Invention] As explained above, the laser corneal treatment device according to the present invention cuts a radial incision line by irradiating a thin laser spot onto the cornea of the eye to be examined while deflecting and scanning it. Since it is possible to change the incision depth by adjusting the amount of laser light irradiated for each part of the cornea, accurate corneal shaping and refractive correction can be performed.

[Brief explanation of the drawing]

The drawings show an embodiment of the laser corneal treatment device according to the present invention, FIG. 1 is a configuration diagram of the first embodiment, FIG. 2 is an explanatory diagram of the incision line on the corneal surface, and FIG. 3 is a two-dimensional deflection diagram. FIG. 4 is an explanatory diagram of the means, FIG. 4 is an explanatory diagram of the condensing optical system, and FIG. 5 is a configuration diagram of the second embodiment. 1 is a laser light source, 2 is a variable attenuator, 3 is a scanner, 3a is a galvano mirror, 14 is a three-sided mirror rotator, 5 is a condenser lens, 6 and 8 are eF optical light deflectors, 9
．． 10 is a cylindrical lens, 11 is a two-dimensional ultrasonic deflector, 13
．． 14 is a half mirror, 116 is a position sensor, 17 is a deflector controller, and 19 is an index light source. Patent applicant Canon Co., Ltd. Figure 1 Figure 3

Claims (6)

[Claims] 1. A device for shaping and treating the cornea using a laser beam, comprising a means for emitting a laser beam, a means for guiding the laser beam to a selected location on the cornea to incise the cornea, and a means for adjusting the intensity of the laser beam during irradiation. A laser corneal treatment device comprising: 2. 2. The laser corneal treatment device according to claim 1, wherein the means for incising the cornea by guiding the laser beam to a selected location on the cornea is configured to incise the cornea radially. 3. 2. The laser corneal treatment device according to claim 1, wherein the means for guiding the laser beam to a selected location on the cornea and incising the cornea is a galvanometer mirror and a three-sided mirror rotator. 4. 2. The laser corneal treatment device according to claim 1, wherein the means for guiding the laser beam to a selected location on the cornea and incising the cornea is a two-dimensional ultrasonic deflector. 5. 2. The laser corneal treatment device according to claim 1, wherein the means for guiding the laser beam to a selected location on the cornea and incising the cornea is an acousto-optic light deflector. 6. 2. The laser corneal treatment device according to claim 1, wherein the means for adjusting the amount of laser light is a variable attenuator.