JP2828212B2 - Ophthalmic laser treatment device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ophthalmic laser treatment apparatus for use in treating cataracts, for example.

[Background Art] Intraocular lens (IOL) transplantation surgery is performed for the treatment of cataracts in which the lens of the eyeball becomes cloudy and vision deteriorates. There is a secondary cataract as a sequela after this IOL transplant. This secondary cataract is the formation of an opaque membrane in the posterior capsule behind the implanted IOL, which reduces vision.

Conventionally, an ophthalmic laser treatment apparatus has been used to treat this secondary cataract. This device uses a high-power pulsed light (wavelength; YAG laser) on the opaque film generated in the posterior capsule.
1064 nm) to generate plasma and destroy the opaque film. That is, the YAG laser beam is focused on a desired affected part through the objective lens, and the affected part is destroyed. In such a case, setting such that the focal point of the YAG laser light is located at a predetermined affected part has been performed as follows. That is, He-Ne laser light (wavelength: 632.8 nm), which is aiming light having the same focal point as the YAG laser light, is applied to the affected part through the objective lens. On the other hand, aiming light applied to the affected part through the objective lens via a half mirror is observed with a microscope. Then, a joystick or the like is operated to move the entire apparatus with respect to the affected part so that the spot of the aiming light is minimized at a desired affected part position. As a result, the position of the focal point of the aiming light coincides with the position of the desired affected part, and as a result, the focal point of the YAG laser light is set at the desired position of the affected part.

[Problems to be Solved by the Invention] When the opaque film formed in the posterior capsule portion is thick, the opaque film may be destroyed even if YAG laser light is focused near the surface of the opaque film. Can not. For this reason, it is necessary to focus the YAG laser light near the center of the thickness of the opaque film or at the rear end.

However, since the aiming light is blocked by the opaque film, the position where the spot of the aiming light is minimized cannot be adjusted to the inside or the rear end of the opaque film. That is, the focusing point position of the YAG laser light cannot be adjusted to the inside or the rear end of the opaque film by the aiming light.

For this reason, conventionally, once, the aiming light
The focusing point position of the YAG laser light is adjusted to the surface of the opaque film, and thereafter, a skilled person operates the joystick of the apparatus to set the focal point of the YAG laser light within the opaque film. It was adjusted so that it was located at the site of the thickness.

This position adjustment is an extremely minute adjustment of the displacement amount,
Even a skilled operator required a remarkably long time for adjustment. Moreover, if the focus point of the YAG laser light is positioned within the IOL by mistake in adjusting the focus point position, the irradiation of the YAG laser light may cause a crack in the IOL. there were.

The present invention has been made under the above-mentioned background,
It is an object of the present invention to provide an ophthalmic laser treatment apparatus capable of quickly and accurately adjusting a focal point of a treatment laser light to a desired portion through which aiming light does not pass.

[Means for Solving the Problems] The present invention has solved the above-mentioned problems by adopting the following configuration.

Treatment laser light generating means for generating a treatment laser light; aiming laser light generation means for generating a focusing point position setting aiming light of the treatment laser light; and focusing the treatment laser light on an affected part. An ophthalmic laser treatment apparatus comprising: a focusing optical system for causing the laser beam for treatment and the aiming light to be introduced into the focusing optical system; and an observation optical system for observing a focusing position of the aiming light. A focusing point position adjusting optical system for moving the focusing point position of the therapeutic laser light relative to the focusing point position of the aiming light between the therapeutic laser light generating means and the optical coupling means; A configuration characterized by intervening.

[Operation] In the above-described configuration, by focusing the treatment laser light at a desired diseased part position via the focusing optical system,
The affected area can be treated.

In this case, the focusing point position of the treatment laser beam is adjusted to a desired affected part position as follows. The convergence point position adjusting optical system is set so that the convergence point position of the therapeutic laser light matches the convergence 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 with respect to the affected part is adjusted so that the focused point position matches a desired affected part position. As a result, the focal point position of the treatment laser beam also coincides with the desired affected part position.

When it is desired to adjust the focusing position of the therapeutic laser light to a predetermined position inside the opaque body, first, as described above,
Using the aiming light, the focal point position is adjusted to the surface of the opaque body. Next, the focusing point position adjusting optical system is operated to adjust the focusing point position of the treatment laser light so as to move forward with respect to the focusing point position of the aiming light. Since the relationship between the amount of operation of the focusing point position adjusting optical system and the amount of movement of the focusing point position of the treatment laser beam can be known in advance, the treatment laser can be obtained by setting this operation amount accurately. The position of the focal point of the light can be precisely adjusted to a position located within a desired distance from the surface of the opaque body.

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

In the figure, reference numeral 1 denotes a YAG that generates a therapeutic laser beam.
Reference numeral 2 denotes a He-Ne laser device for generating aiming light, reference numeral 3 denotes a focusing optical system, reference numeral 4 denotes a beam splitter as an optical coupling means, reference numeral 5 denotes a microscope optical system serving as an observation optical system, and reference numeral 6 denotes a treatment. Reference numeral 7 denotes an eyeball as a treatment target.

The YAG laser device 1 includes an eyeball 7 serving as the treatment target.
It oscillates a high-output pulsed laser beam having a wavelength of 1064 nm that can destroy the affected tissue.

The He-Ne laser device 2 continuously oscillates laser light having a wavelength of 632.8 nm that can be observed without destroying the affected tissue of the eyeball 7.

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

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

The half mirror 32 reflects the laser beam whose beam diameter has been expanded by the beam expander 31 and changes its direction by 90 ° to make it incident on the objective lens 33 and is guided through the objective lens 33. Part of the transmitted light is transmitted and introduced into the microscope optical system 5. That is, the YAG laser beam having a wavelength of 1064 nm is reflected 100%, and the He-Ne laser beam having a wavelength of 632.8 nm is reflected 20%.

The objective lens 33 functions to focus the laser light reflected by the half mirror 32 to a desired position on the eyeball 7 and observes the image of the laser light focusing point position with the microscope optical system 5. In this case, the objective lens also functions as an objective lens. Here, the cone angle of the objective lens 33 is 18 ° (full-width). The He-Ne laser light is focused at a point 98.93 mm away from the lens.

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

The microscope optical system 5 uses the objective lens 33 as an objective lens and uses a variable power optical system (magnification: 0.51 ×, 0.8 ×, 1.28 ×, 2.
05 ×, 3.2 ×) 51, a fuel line absorption filter 52, a half mirror 53, a visual observation system 54, and a photograph observation system 55.

The visual observation system 54 includes an imaging lens 54a,
4b and an eyepiece (magnification: 12.5 ×) 54c, an enlarged image of the affected tissue of the eyeball 7 is formed on the observation eye 8.
On the other hand, the photographic observation system 55 includes an imaging lens 55a and a reflecting mirror 55b, and causes a camera (not shown) to capture an enlarged image of the affected tissue of the eyeball 7.

The focusing point position adjusting optical system 6 gives the YAG laser light emitted from the YAG laser device a predetermined focusing action or a diverging action, so that the YAG laser light is focused on the eyeball 7 by the focusing optical system 3. The position of the focal point for focusing on the affected tissue is changed. In other words, the relative positional relationship between the focal point position of the YAG laser light by the focusing optical system 3 and the focal point position of the He-Ne laser light by the focusing optical system 3 is changed. More specifically, the position of the focal point of the YAG laser
It can be adjusted to a desired position ahead of the focal point position of the e-laser light. As shown in FIG. 1, this focusing position adjusting optical system 6 may combine two plano-convex lenses to change the distance between these two lenses, or use one convex or concave lens. Alternatively, the distance between the lens and the focusing optical system 3 may be changed.

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

In FIG. 2, reference numeral 61 denotes a release main body having a substantially cylindrical shape, and reference numeral 62 denotes an outer peripheral surface of the release main body 61 which is fixed to the release main body 1 in an axial direction so as to be rotatable. Cylindrical outer frame, reference numeral 63 is a moving frame, reference numeral 64 and
65 is a plano-convex lens.

A lens mounting hole is provided at the left end of the release body 1 in the drawing.
The plano-convex lens 64 is housed therein, and is fixed by a ring-shaped screw 64a for holding down the lens.

The release main body 1 is formed with a light passage hole 61b that shares the optical axis of the plano-convex lens 64 with the central axis thereof toward the right in the drawing. This light passage hole 61a communicates with a relatively large diameter guide hole 61c. This guide hole 61c
Has a central axis common to the central axis of the light passage hole 61b, and extends to the right end of the release main body 1 in the figure.

The moving frame 63 is movably fitted in the guide hole 61c. The movable frame 63 has a lens mounting hole 63 at the right end in the figure.
a is formed, the plano-convex lens 65 is housed, and fixed by a ring-shaped screw 65a for holding down the lens. The moving frame 63 is formed with a light passing hole 63b, which is a through hole common to the optical axis of the plano-convex lens 65 and its central axis. Further, a lead pin 63c is erected perpendicularly to the axial direction on the outer peripheral portion of the moving frame 63. 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.

In addition, the guide hole is provided on an outer peripheral portion of the release main body 1.
There is provided a straight guide groove 61e that penetrates through 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, the inclined guide groove 62a is formed so as to form a predetermined angle with the center axis of the outer frame 62. The inclined guide groove 62a and the linear guide groove 61d The lead pin 63c is inserted through a. The outer frame 62 has a knob 62d for operation.
Has been fixed.

Therefore, the outer frame 6 is operated by the operation knob 62a.
2 rotates the inclined guide groove 62a to the lead pin 63
c is driven to move along the straight guide groove 61d.
Thereby, the moving frame 63 is moved in the axial direction, and the distance between the plano-convex lenses 64 and 65 is changed. The plano-convex lens
64 and 65 can move the focus point position of the YAG laser beam by the objective lens 33 by 99.82 to 98.93 mm in front of the objective lens 33 by moving the interval between them by 0 to 4 mm. Each optical system in the above configuration is corrected for spherical aberration and chromatic aberration. In particular, the focusing optical system 3
With regard to (5), if there is a chromatic aberration between the He-Ne laser hole serving as the aiming light and the YAG laser light serving as the treatment laser light, it is impossible to accurately set the position of the focal point. Hereinafter, a specific example in which the chromatic aberration is corrected will be described.

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

Each lens represented by this surface number is constituted by a lens having lens data as shown in FIG. Then, as shown in FIG. 6, He-Ne laser light and YA
An optical system that has very small spherical aberration with respect to both of the G laser beams and is very well corrected can be obtained. In FIG. 5, the surface spacing, the refractive index, and the Abbe number described in the column corresponding to each surface number indicate constants of the optical system between the surface number and the next surface number. In FIG. 6,
The vertical axis H indicates the ray height, that is, the distance (unit: mm) outward from the beam center in the beam cross section, and the horizontal axis indicates the amount of deviation (unit: mm) of the focal point position. The solid curve in FIG. 6 indicates the spherical aberration of the He-Ne laser light, the dashed-dotted curve indicates the spherical aberration of the YAG laser light, and the dotted curve indicates the sine condition.

According to the apparatus having the above-described configuration, the aiming light is used for YAG
The focusing point position of the laser light is adjusted to the surface of the desired position of the opaque body, and then the focusing point adjusting optical system 6 is adjusted by a desired amount to set the focusing point position of the YAG laser light to a desired value. By shifting the YA to a position at a desired distance from the inner surface of the opaque body.
The focusing point position of the G laser beam can be accurately adjusted.

Therefore, the use of this device makes it possible to accurately and quickly treat secondary cataract.

In the above-described embodiment, an example in which the ophthalmic laser treatment apparatus according to the present invention is used for treatment of cataract is described. However, instead of the YAG laser apparatus 1, laser light of another wavelength is generated. By using such a device, the device can be used for other treatments, for example, treatment of cataract.

[Effects of the Invention] As described in detail above, the present invention provides a therapeutic laser light generating means for generating a therapeutic laser light, and an aiming for generating a focusing point position setting aiming light for the therapeutic laser light. Laser light generating means for light; a focusing optical system for focusing the treatment laser light on an affected part; an optical coupling means for introducing the treatment laser light and the aiming light to the focusing optical system; and focusing of the aiming light. An ophthalmic laser treatment apparatus having an observation optical system for observing a position, wherein a focusing point position of the treatment laser light is focused between the treatment laser light generation means and the light coupling means. A focusing point position adjusting optical system that moves relatively to the point position is interposed, so that a therapeutic portion can be applied to a desired portion through which aiming light is not transmitted. Is that obtained the ophthalmic laser treatment apparatus capable of matching the focal point of over The quickly and accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of an ophthalmic laser treatment apparatus according to one embodiment of the present invention, FIG. 2 is a sectional view of a focusing point position adjusting optical system, and FIG. 3 is a focusing point position in FIG. FIG. 4 is a plan view showing a part of the adjusting optical system, FIG. 4 is a diagram showing surface numbers assigned to respective lenses of the focusing optical system, FIG. 5 is a diagram showing lens data, and FIG. 6 is a diagram showing spherical aberration. is there. 1.... YAG laser device for generating 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 of therapeutic laser light, 7 ... eyeball to be treated.

Claims (1)

(57) [Claims] A therapeutic laser light generating means for generating a therapeutic laser light; an aiming laser light generating means for generating a focusing point position setting aiming light for the therapeutic laser light; A focusing optical system that focuses the laser light on the affected part; an optical coupling unit that introduces the treatment laser light and the aiming light into the focusing optical system; and an observation optical system that observes a focusing position of the aiming light. An ophthalmic laser treatment apparatus, comprising: a focusing device that moves a focal point position of the therapeutic laser light relative to a focusing point position of the aiming light between the therapeutic laser light generating unit and the optical coupling unit. An ophthalmic laser treatment apparatus characterized by interposing a point position adjusting optical system.