JPH0924060A - Presbyopia medical treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system to directly correct presbyopia on an eyeball of a patient so that the eyeball of the patient can automatically adapt itself to a focus for nearsightedness or farsightedness by avoiding use of spectacles. SOLUTION: In a presbyopia treating system to surgically correct presbyopia, the system is composed of a mark means to put a mark on a part of an eyeball of a patient to be removed, an excising means containing a horny coat shaper to expose a cellular tissue of the horny coat by excising at least a part of the horny coat of an eyeball of the patient and a removing means containing a laser to remove an annular part of a cellular tissue of the horny coat, and removal is performed by irradiating a cellular tissue of the horny coat by radioactive rays from the laser. A mask is arranged as the removing means, and is arranged so as to cover a central area of a cellular tissue of the horny coat, and the radiation from the laser is checked, and a means is also arranged to give a prescribed light diameter to a beam of light from the laser, and an annular part having a prescribed width and a prescribed depth can be removed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a system for correcting presbyopia by surgical treatment.

[0002]

2. Description of the Related Art Most elderly people suffer from presbyopia. Bifocals are usually used to correct this problem associated with presbyopia.

[0003]

However, some people dislike wearing glasses for various reasons, and the bifocal lenses are especially disliked. Bifocals include a lens junction line that is divided into two parts. Furthermore, the person using this bifocal spectacle must be accustomed to reading near things from a small lens part and seeing things far from another lens part. These bifocals also have the inconvenience of ordinary glasses, such as being fragile, cloudy when entering a warm place from a cold place, cloudy with steam on hot days, or requiring regular cleaning. There is.

The present invention therefore provides a system for correcting presbyopia directly on a patient's eye so that the use of eyeglasses is avoided and the patient's eye automatically adapts to the focus for myopia or hyperopia. The purpose is to do.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a system for surgically correcting presbyopia. The system comprises means for marking and removing a portion of the patient's eye. Means for ablating at least a portion of the cornea of the eye to expose corneal tissue is also included. The system also includes means for removing the annular portion of corneal tissue. This removal means (pulse type laser, etc.)
It is equipped with a laser and is ablated by irradiating the corneal tissue with laser light radiation.

Further, a corneal saver is provided as an excision means, and a part of the cornea is excised while leaving an interaction, or the circular surface of the cornea is completely removed.
The system also has means for drying the corneal tissue after being exposed by the excision means, such as by blowing air.

In order to remove the corneal cellular tissue in a circular manner,
A mask may be provided in the removing means, in which case the mask is placed on the central region of the cellular tissue of the cornea to block the laser light irradiation. A means for imparting a predetermined light diameter to the laser light from the laser is provided in this embodiment, and the width of the laser light is limited to remove the annular portion having the predetermined width and the predetermined depth.

Furthermore, the system according to the invention preferably comprises means for cleaning the removed tissue portion. The cleaning means may be provided with great care, such as by brushing and / or by moistening and cleaning the removed portion.

[0009]

In accordance with the system of the present invention, the patient is anesthetized and a portion of the patient's eye is removed. Here, at least a portion of the cornea is excised to expose its cellular tissue. This corneal tissue is excised by laser light irradiation. This corneal tissue exposed in a ring shape is removed by laser light irradiation. Then, after removal, the cornea is returned to its original position on the eye.

In the system of the present invention, the cornea may be excised by folding back a part of the cornea to expose the cellular tissue of the cornea while leaving the interaction. Alternatively, the entire circular surface of the cornea may be removed from the eye and excised to expose the corneal cellular tissue. The circular surface of this cornea is then reattached onto the eye.

After being exposed by excision, the corneal cell tissue is dried prior to removal. Otherwise, the liquid that appears on the tissue can cause irregularities in the removed area.

During the removing operation, the laser light is sent in a circular manner until the annular portion is removed with a predetermined width and a predetermined depth. Alternatively, a mask may be provided on the central region of the corneal cell tissue, and the irradiation of laser light at the central portion may be stopped. The diameter of this laser should be such that the annulus is removed with a given width and a given depth (and somewhat larger than the mask diameter).
Controlled. This mask is made of polymethylmethacrylate (PMMA) or other suitable synthetic resin. The laser may be a conventional pulsed laser.

After the removing operation, the removed portion is washed to prevent edema. This is accomplished by brushing the removed portion, moistening and cleaning.

When the corneal area is repositioned in place,
It is reattached to the eyeball by blowing air over the cornea.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A system according to the present invention comprises
Consists of an automatic corneal saver, pneumatic fixation ring, mask and air source. An automatic corneal shaper suitable for the system of the present invention is the Automatic Corneal Shaper described in US Pat. No. 5,133,726 by the present inventor issued on July 28, 1992. The invention is incorporated herein by reference.

In this system, local anesthesia is used to fix the eye with a fixation ring that also functions as a guide for the automatic corneal saver. This fixation ring or stop ring allows for comprehensive control of eye movement, as shown in the above-referenced US Pat. No. 5,133,726. Therefore, the pupil is positioned at the reference point so that the tissue from the very center of the cornea is removed.

Then, when the eyeball is fixed, corneal resection is performed using an automatic corneal saver. This corneal ablation may be partial, meaning that the corneal flap technique (a technique of partially cutting the cornea) is used. That is, one end of the circular surface of the cornea is left attached to the base of the cornea, which allows the cornea to be returned to its original position in a simple and reliable manner. When this flap is excised, the corneal cell tissue in the targeted tissue portion for achieving removal is exposed. Here, the layers near the surface of the cornea are kept intact. In this way, undesired post-treatment is avoided as well as post-correction errors and regressions.

Then, using an excimer laser capable of accurately removing 0.24 μm per pulse, 2-3 mm
The tissue is annularly removed on tissue having a diameter not exceeding 3.5 mm, including the central zone varying between. When the corneal flap is returned to its original position,
As this curvature change of cell tissue is transmitted to the front surface of corneal surface, removal of this annular portion creates a central protrusion in cell tissue, so that the corneal surface can be transformed into a multifocal surface. The central part becomes myopic. this is,
It allows the patient to read in the near field without vision correction, regardless of the patient's age or loss of accommodation of the crystalline lens of the eye. The removal of the annular portion can be performed independently for presbyopia correction, or with correction of hyperopia, myopia and astigmatism, and may be performed independently or as a mixture. After this removal work, in order to ensure that the interface is free of impurities, epithelial layer cells, foreign particles, etc., inject a stable saline solution, apply a brush, suction it, and thoroughly wash the interface. Processing continues. The flaps are then properly oriented and returned so that they do not reposition their original position. The edges of the flaps are dried by applying air for a few seconds to achieve its tightness so that the patient can leave the operating room without the eyepatch and the recovery time can be less than 24 hours.

Next, an example of an apparatus for presbyopia orthopedic surgery and a treatment method thereof will be described in more detail below. First,
Conventional topical (ie, eye drop) anesthesia is applied to the patient's eye. This topical anesthesia method corresponds sufficiently to the surgical technique of the present invention, which is performed painlessly. next,
A pneumatic fixation ring is placed over the eye.

In this type of surgery, it is essential to center the device on the pupil of the eye. Furthermore, it is desirable to make the pupil range as small as possible. Therefore, approximately 1% of isopt
Good to drip carpine. From then on, this small pupil is used as a reference point for performing the removal task. The surgical procedure according to the present invention is accomplished in a sterile location (ie, operating room). This is because the cornea must be contacted rather than the superficial method required for optical removal of myopic correction. on the contrary,
In the surgical method of presbyopia correction of the present invention, the corneal flap is lifted into a thin film in order to act directly on the cell tissue. Therefore, a surgical site is set up to isolate the work area and a device is provided to keep the eyelid stable in order to keep the eye fully exposed so that surgery can be performed.

Markers are effectively used to support the practice of the present invention. The marker used in this new procedure is in the form of a bulllock eye with two concentric circles (which can form an inner ring and an outer ring), the outer portion of which is approximately 10.5.
The inner part has a diameter of approximately 3-5 mm. This marker is soaked with a colored product such as ginger purple or methylene blue and placed on the eyeball of the patient. The inner ring has the function of aligning the center of the marker by using the pupil as a reference point. In this way, the outer ring automatically marks, and this mark is then used as a reference when positioning the pneumatic retaining ring. In addition to these two rings, the marker is also provided with auxiliary radiation that joins both rings. This supplemental radiation helps to properly orient the corneal flap. Also, instead of using a corneal flap, if a surgical procedure removes a completely isolated circular surface of the cornea, it should help to put the circular surface in place, i.e., the epithelium to the external surface. This auxiliary radiation is used to direct the tissue towards the interior, and as soon as it is placed in this way, it is oriented to the proper shape.

The pneumatic retaining ring consists of two main components. The ring itself is adapted to the eyeball by means of the vacuum chamber means in the bottom, so that the eyeball can be held in place and the internal intraocular pressure can be increased. This facilitates uniform application of the necessary ablation in the cornea. The fixation ring also has a central hole through which the cornea projects. At its top, there is a line of teeth, the most important component of the fixation ring, which contacts the wing of an automatic corneal saver (US Pat. No. 5,133,72).
6). This allows the corneal saver to be moved horizontally to perform a lamina excision in the cornea.
The second component of this ring is then the handle that communicates with the vacuum pump to place the bottom vacuum chamber of the fixed ring. This vacuum pump acts as a suction to bring the ring onto the patient's eye. This handle is also used to maneuver the eye as soon as the ring is secured to the eye.

The next step in the surgical procedure is performed by an automated corneal saver, as described above. The saver is placed over the fixation ring, and as soon as the tip of the saver contacts the toothed projection of the ring, the saver motor is activated and the saver moves in a uniform and parallel manner over the cornea. Then, the cutter of this saver makes a very precise thin film cutting in its thickness state as described in US Pat. No. 5,133,726.

The motor of the saver is preferably stopped at a predetermined position on the cut surface so that the thin portion of the cornea is still fixed on one surface. When this thin portion is lifted up, corneal cell tissue appears. This corneal tissue is where surgery is performed. Because, after removal of the tissue, the corneal flaps, when installed in place, will topographically change, while retaining all of the eye's natural composition in place. The great advantage is that it avoids unwanted treatments and other modifications that would otherwise occur if the system were not used.

Once the exposed cell tissue surface is examined, it must be dried prior to its excision action by the excimer laser. This is because if any fluid remains on the cell tissue surface, it is regarded as corneal tissue by the laser light. This will result in irregular removals. That is, different depths of ablation will be produced on the tissue.

One of the key components of this new system for presbyopia correction is the excimer laser. The excimer laser system, as shown in FIGS. 1 and 2, each requires a method for producing a multifocal plane in the cornea that allows not only a perfect near field but also a perfect far field. This is to perform this visual weakness correction by providing removal of cellular tissue at location and depth. This field of view is usually lost during the later years of human life due to physical loss of lens accommodation and loss of elasticity of the lens.

This system consists of a novel combination of the above elements provided to obtain an annular ablation area within the corneal area not used for far vision. They are,
It is the theoretical and true foundation of the presbyopia correction system according to the invention. There are several different ways to achieve that result and they are described below.

In one embodiment, the laser is aimed at the zone where the ablation is to occur. Since the laser is delivered in a circular motion of the laser beam so that the removal is made with the required width and depth, the desired curvature change can be obtained. For this reason,
The device for delivering the laser beam is provided with an eye tracking system that follows any movement of the eye, so that it does not generate an irregular removal ring section.

In another embodiment, as shown in FIG. 3, a small pupil is used as a reference point to emit a laser beam toward the center of a selected area. And to prevent the laser light from touching the corneal tissue in the central region,
A mask is installed so as to cover the central region. In this way, the selected light diameter of the laser beam delimits the removed portion on the outside thereof and on the inside thereof by the boundary of the mask, so that an annular region is left as shown in FIGS. 4 and 5. You can By using the mask, the part of the cornea covering the pupil is entirely retained.

In consideration of the above, the surgical method for presbyopia correction proceeds as follows. That is, when the tissue is totally dried, it is masked in the areas not exposed to the laser beam. The area is called the visual zone, considering the basic elements that successfully focus the working rays in the center of the visual area. The diameter of this visual zone should be between about 2-3 mm.

Here, a mask is provided so as to cover the marked area. This mask is made of a material that blocks a laser beam, and a material called polymethyl methacrylate (PMMA) is generally used. Also, this mask has the same dimensions as the marks already applied.

The laser device is installed so as to supply the laser beam onto the cornea. The laser system is commercially available, for example, manufactured by Chiron Technologies GmbH. The laser device is pre-installed in order to obtain a laser beam with a desired diameter.
The laser device is also assembled to provide the predetermined number of pulses required to perform the ablation while maintaining an appropriate depth so as to produce the corneal curvature change necessary to obtain the multifocal effect. There is. Retaining the eye with a pneumatic fixation ring allows the very uniform removal ring to be maintained while the laser beam is acting on the cornea, and primarily when the laser device is not equipped with an eye tracking system. It is also convenient in view of the fact that can be generated.

Upon completion of this removal step, the mask is retrieved and the treated zone is inspected and thoroughly cleaned to ensure that there are no residual epithelial layer cells or foreign particles on the surface. This washing step is usually accomplished by meticulous brushing and continuous washing with a stable saline solution having an osmolarity similar to that of the cornea. This helps avoid the significant edema induced there, which prolongs the recovery time of the patient.

On the therapeutic side, it is now ready to accept the flaps that need to be put back in its proper place, perfectly directional and with pleats that induce corneal astigmatism, diminishing the visual field, etc. Absent. Then, when the flap is replaced again, the tissue is dried, mainly with air leaking towards its boundaries, so that the flap's perfect adherence to the treatment surface can be obtained.
This adhesion can be verified with tweezers or tested.

When the tissues are brought into close contact with each other, the device for keeping the eyelids stable and the one provided at the operation site are retrieved, and the patient is asked to blink or tightly close both eyes several times. The adhesion of is further tested. If no complications are seen here, the surgery is successfully completed.

Although the present invention has been described above with reference to a number of embodiments and methods of carrying out its treatment, various changes and modifications can be made without departing from the scope of the invention as defined by the claims. Those skilled in the art will recognize that

[0037]

As described in detail above, the system used in the present invention (referred to as a geriatric system) is composed of various different elements, and these elements are used together to perform pre-corneal surgery. By modifying the curvature of the part, it is possible to create a multifocal plane that allows the patient to see objects at a long distance in the normal field of view as well as seeing close objects in the normal field of view as well. This allows the patient to avoid the inconvenience associated with bifocals.

Thus, in the present invention, simultaneous near and far field correction of the cornea is achieved using only a portion of the (intermediate) corneal layer. That is, this means that the corneal region portion used for the short-distance visual field is different from the portion used for the long-distance visual field, and causes the corneal curvature change necessary for obtaining the multifocal effect. As such, it allows the patient to read without the vision correction of eyeglasses, despite the patient's age and loss of accommodation of the crystalline lens of the eye.

Further, when the corneal flap is lifted and treated, only the corneal cell tissue to be removed is removed, and then the corneal flap is returned to its original position to restore all the original constitution of the eyeball to its original state. Because it is kept in place, it changes topographically, and thus avoids unwanted post-operative treatments and modifications.

[Brief description of drawings]

FIG. 1 is a schematic view showing a part of an excimer laser in which an optical axis of laser light is set.

FIG. 2 is a schematic view showing an optical system and an optical path of laser light used in an embodiment according to the present invention.

FIG. 3 is a diagram showing a laser beam for performing removal on the cornea and a mask for protecting the central region of the cornea.

FIG. 4 shows a ring of a removal zone.

FIG. 5 is a diagram showing a removed portion of a cornea that finally appears.

Claims (9)

[Claims] 1. A presbyopia treatment system for surgically correcting presbyopia, and a marking means for marking a part of the eyeball of the patient to be removed, and corneal cells by cutting off at least a part of the cornea of the eyeball of the patient. The ablation means for exposing the tissue and the removing means including a laser for removing the annular portion of the cellular tissue of the cornea, and the removal is performed by irradiating the cellular tissue of the cornea with radiation from the laser. Presbyopia treatment system characterized by. 2. The presbyopia treatment system according to claim 1, wherein the excision means includes a corneal saver, and the cornea is partially excised while a part of the cornea remains interactive. 3. The presbyopia treatment system according to claim 1, wherein the excision means includes a corneal saver, and by completely removing the circular surface of the cornea, the cellular tissue of the cornea is exposed. 4. The presbyopia treatment system according to claim 1, further comprising means for drying the cellular tissue of the cornea after being exposed by the excision means. 5. The removing means comprises a mask, and the mask is installed so as to cover the central region of the cellular tissue of the cornea so as to block the emission from the laser, and the removing means has a predetermined function for the light beam from the laser. The presbyopia treatment system according to claim 1, further comprising a means for imparting a light diameter, wherein an annular portion having a predetermined width and a predetermined depth is removed. 6. The presbyopia treatment system according to claim 5, wherein the mask is manufactured from methyl polymethacrylate. 7. The presbyopia treatment system according to claim 1, wherein the laser is a pulsed laser. 8. The presbyopia treatment system according to claim 1, further comprising cleaning means for cleaning the removed portion. 9. The presbyopia treatment system according to claim 8, wherein the cleaning means comprises a brush and means for cleaning the removed portion by moistening the removed portion.