JPH03118060A - Ophthalmologic laser treatment device - Google Patents

Abstract

PURPOSE:To speedily and exactly match the convergent point of a laser beam for treatment by interposing a convergent point position control optical system between a laser beam generating means for treatment and a photocoupling means so that the convergent point position of the laser beam for treatment can be relatively moved to the convergent point position of aiming light. CONSTITUTION:A convergent point position control optical system 6 changes the convergent point position for a YAG laser beam, which is emitted from a YAG laser device, to be converged to the diseased organism of an eyeball 7 by a converging optical system 3 by applying prescribed convergent operation or distribution operation to this YAG laser beam. The convergent point position control optical system 6 can control a distance between two flat and convex lens by using a so-called release mechanism. The convergent point position of the YAG laser beam is matched with the surface of a desired position on an opaque body by the aiming light and the convergent point position control optical system 6 is controlled only by a desired amount. Then, by deviating the convergent point position of the YAG laser beam forward only by the prescribed distance, the convergent point position of the YAG laser beam exactly is matched with a position separated from the internal surface of the opaque body only by the prescribed distance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ophthalmic laser treatment device used, for example, in the treatment of cataracts.

[Prior Art] Intraocular lens (10L) implantation surgery is performed to treat cataracts in which the crystalline lens of the eyeball becomes cloudy and reduces visual acuity. Secondary cataract occurs as a sequela after this IOL implantation. In this secondary cataract, an opaque film is formed on the posterior progeny of the implanted IOL, resulting in decreased visual acuity.

Ophthalmic laser treatment devices have been used to treat secondary cataracts. This device uses high-power pulsed light from a YAG laser (
The opaque film is destroyed by irradiating the opaque film with a wavelength of 11064n to generate plasma. That is, YAG laser light is focused on the desired affected area through an objective lens,
Destroy the affected area. In this case, setting the focal point of the YAG laser beam to be located on a predetermined affected area was performed as follows. That is, the aiming light I-(e-Ne
Laser light (wavelength: 632.8 nm) is irradiated onto the affected area through the objective lens. On the other hand, the aiming light irradiated onto the affected area through the objective lens through a half mirror is observed with a microscope. Then, the entire device is moved relative to the affected area by operating a joystick or the like so that the spot of the aiming light becomes minimum at the desired affected area position.

As a result, the focusing point position of the aiming light coincides with the desired affected area position, and as a result, the YA
The focal point of the G laser beam will be set at the desired affected area position.

[Problems to be Solved by the Invention] By the way, if the opaque film formed in the fAa portion is thick, the opaque film cannot be destroyed even if the YAG laser beam is focused near the surface of the opaque film. . Therefore, it is necessary to focus the YAG laser beam near the center of the thickness of this opaque film or at the rearmost part.

However, since the aiming light is blocked by the opaque film, it is not possible to align the position where the spot of this aiming light is minimum to the inside of the opaque film or the rearmost part.

That is, it is not possible to align the focal point of the YAG laser beam with the inside or rearmost part of the opaque film using the aiming light.

For this reason, conventionally, aiming light is used to
The focal point of the AG laser beam is aligned with the surface of the opaque film, and then a skilled person operates the joystick of the device to align the focal point of the YAG laser beam to a desired location inside the opaque film. It was adjusted so that it was located in the area of thickness.

This position adjustment involves an extremely small amount of displacement, and requires an extremely long time even for an experienced operator. Moreover, if you make a mistake in adjusting the focal point position,
When the focal point of the YAG laser beam is located within the IOL, the IOL is irradiated with the YAG laser beam.
There was also a risk of causing cracks in the OL.

The present invention was made against the above-mentioned background, and provides an ophthalmic laser treatment that makes it possible to quickly and accurately align the focal point of a therapeutic laser beam even in a desired area where the aiming light does not pass through. The purpose is to provide equipment.

[Means for Solving the Problems] The present invention solves the above problems by having the following configuration.

A therapeutic laser beam generating means for generating a therapeutic laser beam; Aiming laser beam generating means for generating an aiming beam for setting a focal point position of the therapeutic laser beam; In an ophthalmologic laser treatment apparatus, the ophthalmologic laser treatment apparatus includes: a focusing optical system that causes the laser beam to be focused; an optical coupling unit that introduces the therapeutic laser beam and the aiming light into the focusing optical system; , a focusing point position adjusting optical system is provided between the therapeutic laser beam generating means and the optical coupling means to move the focusing point position of the therapeutic laser beam relative to the focusing point position of the aiming light. Configuration 9 characterized by intervening [Operation] In the above-described configuration, by focusing the therapeutic laser beam on a desired affected area position via the focusing optical system, it is possible to treat the affected area. .

In this case, the focal point position of the therapeutic laser beam is adjusted to the desired affected area position in the following manner. The focusing point position adjusting optical system is set so that the focusing point position of the therapeutic laser beam matches the focusing point position of the aiming light. The focusing point position of the aiming light is observed by the observation optical system, and the position of the focusing optical system relative to the affected area is adjusted so that the focusing point position coincides with the desired affected area position. Thereby, the focal point position of the therapeutic laser beam also coincides with the desired affected area position.

If the focusing position of the therapeutic laser beam is not to be aligned with a predetermined position inside the opaque body, first, as described above, the aiming light is used to align the focusing point with the surface of the opaque body. Next, the focusing point position adjusting optical system is operated to adjust the focusing point position of the therapeutic laser beam to move forward with respect to the focusing point position of the aiming light.

The relationship between the amount of operation of the focal point position adjustment optical system and the amount of movement of the focal point position of the therapeutic laser beam can be known in advance, so by accurately setting this amount of operation, the therapeutic laser The light convergence point position can be precisely adjusted to a position that is within a desired distance from the surface of the opaque body.

[Example] Fig. 1 is a block diagram showing the configuration of an ophthalmic laser treatment device according to an embodiment of the present invention, Fig. 2 is a cross-sectional view of a focusing point position adjustment optical system, and Fig. 3 is a diagram showing the configuration of an ophthalmic laser treatment device according to an embodiment of the present invention. FIG. 3 is a plan view showing a part of the focusing point position adjusting optical system. Hereinafter, one embodiment will be described in detail with reference to these drawings.

In the figure, reference numeral 1 indicates YAG that generates therapeutic laser light.
Laser device, code 2 is He-Ne for generating aiming light
A laser device, 3 is a focusing optical system, 4 is a beam splitter as an optical coupling means, 5 is a microscope optical system which is an observation optical system, 6 is an optical system for adjusting the focal point position of the therapeutic laser beam, and 7 is a laser device. The target of treatment is the eyeball.

The YAG laser device 1 targets the eyeball 7, which is the object to be treated.
This device emits high-power pulsed laser light with a wavelength of 1064 nm that can destroy the affected tissue.

The He-N e laser device 2 has a wavelength of 632.8 n that allows observation of the affected tissue of the eyeball 7 without destroying it.
It continuously oscillates a laser beam of m.

The focusing optical system 3 includes a beam expander 31, a half mirror 32, and an objective lens 33.

The beam expander 31 is composed of a concave lens 31a and a convex lens system 31b, and expands the beam diameter of the laser beam (15 times in this embodiment) to facilitate subsequent processing in the optical system.

Further, the half mirror 32 reflects the laser light whose beam diameter has been expanded by the beam expander 31, changes its direction by 90 degrees, makes it incident on the objective lens 33, and guides it through the objective lens 33. A part of the emitted light is transmitted and introduced into the microscope optical system 5. That is, YAG laser light with a wavelength of 11064 nm is 100% reflected, and He - with a wavelength of 632.8 nm is reflected.
20% of the Ne laser beam is reflected.

The objective lens 33 has the function of focusing the laser beam reflected by the half mirror 32 on a desired position of the eyeball 7, and the function of observing the image of the focal point position of this laser beam with the microscope optical system 5. This lens also functions as an objective lens. Here, the cone angle of this objective lens 33 is 18° (full angle).

Further, the He-Ne laser beam is directed to the front 9 of the lens.
It focuses on a point 8.93 mm apart.

The beam splitter 4 introduces the YAG laser beam emitted from the YAG laser device 1 and the He-Ne laser beam emitted from the He-Ne laser device into the focusing optical system 3. be.

The microscope optical system 5 uses the objective lens 33 as an objective lens, and has a variable magnification optical system (magnification: o, six, 0.8×, 1
．． 28X, 2.05X, 3.2X)51. It is composed of a heat ray absorption filter 52, a half mirror 53, a naked eye observation system 54, and a photographic observation system 55.

The naked eye observation system 54 includes an imaging lens 54a, a Porro prism 54b, and an eyepiece lens (magnification: 12.5X) 54.
c, and forms an enlarged image of the affected tissue of the eyeball 7 on the viewing eye 8. On the other hand, the photographic observation system 55 includes an imaging lens 55a and a reflecting mirror 55b, and forms an enlarged image of the affected tissue of the eyeball 7 on a camera (not shown).

The focusing point position adjusting optical system 6 applies a predetermined focusing effect or diverging effect to the YAG laser beam emitted from the YAG laser device, so that the YAG laser beam is transferred to the eyeball 7 by the focusing optical system 3. This changes the position of the focal point focused on the affected tissue. In other words, there is a method for changing the relative positional relationship between the focal point position of the YAG laser beam by the focusing optical system 3 and the focal point position of the He-Ne laser beam by the focusing optical system 3. Furthermore, in other words, the focal point position of the YAG laser beam can be adjusted to a desired position in front of the focal point position of the He--Ne laser beam. As shown in FIG. 1, this focusing position adjusting optical system 6 may be configured by combining two plano-convex lenses and changing the distance between these two lenses, or by using one convex or concave lens. , the distance between this lens and the focusing optical system 3 may be changed.

FIG. 2 is a sectional view showing details of the focusing point position adjusting optical system 3 constructed by combining two plano-convex lenses. This focusing point position adjusting optical system 3 is configured to use a so-called release mechanism to adjust the distance between two plano-convex lenses.

In FIG. 2, the reference numeral 61 denotes a release body having a substantially cylindrical shape, and the reference numeral 62 fits on the outer peripheral surface of the release body 61 so as to be fixed in the axial direction but rotatable relative to the release body 1. 63 is a moving frame, and 64 and 65 are plano-convex lenses.

A lens mounting hole 6 is provided at the left end of the release body 1 in the figure.
1a is formed to house the plano-convex lens 64, and is fixed by a ring-shaped screw 64a for holding the lens.

Further, in the release body 1, a light passage hole 61b is formed toward the right in the figure, making the optical axis of the plano-convex lens 64 common to its central axis. This light passage hole 61a is
It communicates with a relatively large-diameter guide hole 61c. The guide hole 61c has its central axis common to the central axis of the light passage hole 61b, and extends to the right end of the release body 1 in the figure.

The moving frame 63 is movably fitted into the guide hole 61c. A lens mounting hole 63a is formed in the moving frame 63 at the right end in the figure, and the plano-convex lens 65 is housed therein.
It is fixed by a ring-shaped screw 65a for holding the lens. Further, the plano-convex lens 65 is attached to the moving frame 63.
A light passing hole 6 that is a through hole that shares the optical axis of the
3b is formed. Furthermore, a lead pin 63c is vertically erected and fixed on the outer peripheral portion of the moving frame 63 in the axial direction. Further, a compression coil spring 66 is interposed between the bottom surface 61d of the guide hole 61c and the left end surface 63d of the moving frame 63.

Further, the guide hole 6 is provided in the outer peripheral portion of the release body 1.
A linear guide hole 61e is provided that penetrates through the guide hole 61c and is formed so that its longitudinal direction is parallel to the central axis of the guide hole 61c.

On the other hand, the outer frame 62 is provided with an inclined guide groove 62a. As shown in FIG. 3, this inclined guide groove 62a is formed to form a predetermined angle with the central axis of the outer frame 62, and between this inclined guide groove 62a and the straight guide groove 61d, The lead pin 63c is pushed through a. Note that an operating knob 62b is fixed to the outer frame 62.

Therefore, when the outer frame 62 is rotated by the operation knob 62a, the inclined guide track 62a drives the lead pin 63c to move it along the straight guide track 61d. As a result, the movable frame 63 is moved in the axial direction, and the distance between the plano-convex lenses 64 and 65 is changed. The plano-convex lenses 64 and 65 move the distance between them by 0 to 4 mm, so that the objective lens 33
The focal point position of the YAG laser beam is determined by the objective lens 3.
Note that each optical system in the above configuration is corrected for spherical aberration and chromatic aberration. In particular, regarding the focusing optical system 3, if there is chromatic aberration between the H e - Ne laser beam that is the aiming light and the YAG laser beam that is the therapeutic laser beam, it becomes impossible to accurately set the focusing point position, so it is extremely difficult to set the focusing point position accurately. Strict chromatic aberration correction has been applied. Specific examples in which this chromatic aberration is corrected are listed below.

Now, each surface of each lens of the focusing optical system 3 is given a surface number M1 to M16, as shown in FIG. In the example shown in FIG. 4, the focusing point position adjusting optical system 6 includes one
This is an example in which two plano-convex lenses are used.

If each lens represented by this surface number is configured with a lens having lens data as shown in Fig. 5, then as shown in Fig. 6, it will respond to both He-Ne laser light and YAG laser light. There is only extremely small spherical aberration,
An extremely well corrected optical system is obtained. In addition,
In FIG. 5, the interplanar spacing, refractive index, and Abbe number written in the column corresponding to each surface number indicate the constants of the optical system between that surface number and the next surface number. In FIG. 6, the vertical axis H indicates the ray height, that is, the distance outward from the beam center in the beam cross section (unit: mm), and the horizontal axis indicates the amount of deviation of the focal point position (unit: mm). ) is shown. The solid line curve in Figure 6 is He-Ne laser light, and the - dotted line curve is Y.
This shows the spherical aberration of the AG laser beam, and the dotted curve shows the sine condition.

According to the apparatus having the above-mentioned configuration, the aiming light targets YAG.
The focal point position of the laser beam is aligned with the surface of the opaque body at a desired position, and then the focal point position adjustment optical system 6 is adjusted by a desired amount to adjust the focal point position of the YAG laser beam to the desired position. By shifting the YAG laser beam forward by a distance of , the focal point position of the YAG laser beam can be accurately adjusted to a position at a desired distance from the inner surface of the opaque body.

Therefore, by using this device, it becomes possible to accurately and quickly treat secondary cataracts.

In the above-mentioned embodiment, the ophthalmic laser treatment device according to the present invention is used for treating cataracts, but instead of the YAG laser device 1, laser light of another wavelength may be generated. By using a device that does this, the device can also be used for other treatments, such as the treatment of glaucoma.

[Effects of the Invention] As described in detail above, the present invention comprises: a therapeutic laser beam generating means that generates a therapeutic laser beam; and an aiming device that generates an aiming light for setting the focal point position of the therapeutic laser beam. an optical laser beam generating means; a focusing optical system that focuses the therapeutic laser beam on the affected area; an optical coupling device that introduces the therapeutic laser beam and the aiming light into the focusing optical system; and a focusing optical system that focuses the therapeutic laser beam on the affected area. In an ophthalmological laser treatment apparatus comprising an observation optical system for observing a position, a focusing point position of the therapeutic laser beam is set between the therapeutic laser beam generating means and the optical coupling means to focus the aiming light. It has a configuration characterized by intervening a focusing point position adjustment optical system that moves relative to the point position, which allows the therapeutic laser beam to be focused even on desired areas where the aiming light does not pass through. The present invention provides an ophthalmologic laser treatment device that allows points to be aligned quickly and accurately.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall configuration of an ophthalmic laser treatment device according to an embodiment of the present invention, FIG. 2 is a sectional view of a focusing point position adjustment optical system, and FIG. 3 is a focusing point position in FIG. 2. A plan view showing a part of the adjustment optical system, Figure 4 is a diagram showing the surface numbers assigned to each lens of the focusing optical system, Figure 5 is a diagram showing lens data, and Figure 6 is a diagram showing spherical aberration. be. 1... YAG laser device that generates therapeutic laser light,
2... He-Ne laser device for generating aiming light,
3... Focusing optical system, 4... Beam splitter as optical coupling means, 5... Microscope optical system as observation optical system,
6... Focusing point position adjustment optical system for therapeutic laser light, 7.
...Eyeballs to be treated.

Claims (1)

[Scope of Claims] Treatment laser beam generation means for generating a treatment laser beam; aiming light laser beam generation means for generating an aiming beam for setting a focal point position of the treatment laser beam; and the treatment. a focusing optical system that focuses therapeutic laser light on the affected area; an optical coupling unit that introduces the therapeutic laser light and the aiming light into the focusing optical system; and an observation optical system that observes the focusing position of the aiming light. In the ophthalmologic laser treatment device, a focal point position of the therapeutic laser beam is moved relative to a focal point position of the aiming light between the therapeutic laser beam generating means and the optical coupling means. An ophthalmic laser treatment device characterized by interposing a focal point position adjustment optical system.