RU2256430C1 - Method for implanting intracorneal lens - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: method involves making arc-shaped incision in sclera in meridian interval where no eye muscle tendon fastening takes place at the depth of penetration beyond the episcleral layer. Then tunnel is built in sclera and corneal stroma layer directed towards the corneal optical center where a pocket coupled with lens in shape is built and implanted into the built pocket cavity. The lens is manufactured from biological polymer material and shaped as sphere, cylinder or prism.

EFFECT: enhanced effectiveness of treatment; reduced risk of nerve fiber injuries and infectious complications; reduced postoperative astigmatism; excluded lens dislocation.

6 cl, 2 dwg

Description

The invention relates to medicine, in particular to ophthalmology, and can be used for implantation of an intra-corneal lens in keratoplasty to correct eye refraction with hyperopia, nearsightedness, astigmatism and improved vision in keratoconus, keratotorus, keratoglobus and macular degeneration.

Currently widely used methods of surgical improvement of hyperopia. So, there is a known method of surgical correction of myopia and farsightedness by introducing a ring-shaped implant into the interlayer tunnel through four sections of the surface layers of the cornea (Luengo V.M. Combined tunnel keratoplasty as a method for correcting myopia. Diss. MD, M., 1980, 133 s.).

The closest analogue of the claimed invention is a method of surgical correction of myopia and farsightedness by introducing an implant with a formed pocket through an incision in the epithelium of the cornea and superficial layers of the stroma (Belyaev BC et al. Some issues of refractive brephoplasty of the cornea // Bulletin of Ophthalmology, 1970, No. 2, p. 28- 33).

The disadvantage of this method is the decrease in visual acuity with any correction compared to the preoperative maximum visual acuity, often caused by surgical scars, a decrease in twilight vision and a delayed restoration of visual acuity after bright glare of the eyes with bright light, flash ("glare effect"). This is especially important for people driving vehicles in the evening and at night. There are also complaints about double objects, which may be due to the manifestation of aniseikonia.

Any mechanical (including surgical) damage to the cornea entails a violation of its nutrition and damage to nerves located in large numbers mainly in the surface layers of the cornea.

The aim of this invention is to create a universal method for surgical improvement of vision by implanting a lens, eliminating the growth of corneal epithelium along the formed pocket, minimizing the risk of infectious complications, significantly reducing the delayed complication of corneal astigmatism due to the absence of postoperative scar, while damage to nerve fibers is virtually eliminated. passing in the cornea radially from the limb, and, consequently, the associated violation of its trophism, sensitive innervation.

The essence of the invention lies in the surgical improvement of vision by implantation of an intra-corneal lens. The lens implantation method is carried out by cutting the sclera under the upper eyelid in the interval of the meridian from 9 to 12, 12 to 3, from 3 to 6 and from 6 to 12 hours, excluding the value of the meridian of 9, 12, 3 and 6 hours. The advantage is given to the meridian interval from 12 to 3. The exception of the meridian value of 9, 12, 3 and 6 hours is significant, since tendons of the muscles of the eyeball are attached to these points. In the case of an incision during the operation at the points of the indicated meridians, the healing period and pain postoperative syndrome for the patient are increased. Then sclera and stroma of the cornea are stratified, a pocket is formed in the shape of a lens into which a lens implant is inserted.

Figure 1 shows the general structure of the eye: 1 - sclera, 2 - choroid, 3 - retina, 4 - a. ciliaris post. brevis, 5 - n. opticus, 6 - a. ciliaris post.longa, 7 - v. vorticosa, 8 - m. rectus inf, 9 - a. ciliaris ant., 10 - circulus arteriosus major, 11 - iris, 12 - cornea, 13 - circulus arteriosus minor, 14 - conjunctiva, 15 - lens, 16 - ciliary body, 17 - a. ciliaris ant., 18 - m. rectus sup.

Figure 2 shows the angle of the anterior chamber (sagittal section): 1 - sclera, 2 - limbus corneae, 3 - conjunctiva, 4 - endothelium, 5 - substantia propria, 6 - epithelium, 7 - cornea, 8 - iris, 9 - anterior chamber, 10 — back chamber, 11 — lens, 12 — zonula Zinnii, 13 — processus ciliares, 14 — corpus ciliare, 15 — m. ciliaris.

The sclera (1 in FIGS. 1, 2) or the protein membrane consists of dense collagen fibers, contains a significant amount of elastic fibers and relatively few cells, the thickness of the sclera ranges from 0.5-1 mm. The sclera is poor in blood vessels, and only the relatively built outer layers of it, the so-called episclera, contain more vessels. The front of the sclera is covered with conjunctiva.

At the junction of the sclera with the cornea, a shallow translucent groove is formed - a limb (2 in Fig. 2). The transparent cornea is inserted into the sclera in front and contains five layers, the surface is the epithelium, then the structureless bowman membrane is located, then the stroma, which is adjacent to the structureless and elastic Descemet's membrane, coated from the back surface with one layer of endothelial cells.

The dashed line shows the course of surgical intervention on the eye according to the proposed method for implanting an intra-corneal lens.

The method is as follows.

Under the operating microscope, an optical zone is noted with a diameter corresponding to the diameter (shape) of the implanted intra-corneal lens, and a section meridian. The conjunctiva is separated from the sclera. Then, an incision is made in the front of the sclera in the interval of the meridian from 9 to 12 and from 12 to 3 hours (in the absence of attachment of the tendons of the muscles of the eyeball, preferably from 12 to 3 hours), up to 8 mm long. At a distance from the limb (for example, 0.5-5.0 mm), an arcuate incision of the sclera is carried out to a depth, penetration beyond the episclera layer (for example, 200-450 microns). At the depth of the incision, the sclera and stroma of the cornea consistently create a tunnel in the layers to the borders of the marked optical zone of the cornea. The formed tunnel is washed with balanced saline and a lens is implanted. The edges of the conjunctival incision are sealed with a thermocauter or sutured.

Dosage of the refractive effect of the operation is achieved by the characteristics of the lens (dimensions - diameter, thickness; volume - sphere, cylinder, prism; diopter, material) and its depth in the stroma of the cornea, as well as the location of the section meridian and the optical zone.

The progress of the lens implantation operation is shown by a dashed line in FIGS. 1 and 2.

An example of a specific implementation:

The implantation of intra-corneal lenses was carried out in the following way: an arched incision was made in the sclera in the meridian for 2 hours at a penetration depth beyond the layer of episclera with a bulge facing the limb (frown incision) to a depth of 150 μm. Then, a stratifier in the layers of the sclera and corneal stroma creates a tunnel in the direction of the optical center of the cornea. Form a pocket in the shape of a lens. The formed channel is thoroughly washed with a balanced saline solution. Then insert the lens into your pocket. After implantation of the lens, the edges of the conjunctival incision are sealed with a thermocauter.

In the postoperative period, instillation with antibacterial drops was performed. The total follow-up period was 60 days. Throughout the observation period of infectious complications, epithelial ingrowth, corneal opacity was not observed.

As a result of implantation of the lens according to the proposed method, the following technical result is achieved:

1. The damage to nerve fibers passing in the cornea radially from the limb and, consequently, the violation of its trophism and sensitive innervation is minimized;

2. The ingrowth of the corneal epithelium along the formed pocket is excluded;

3. Significantly reduced corneal astigmatism, as there is no incision of the cornea and, therefore, the postoperative scar of the cornea;

4. The dislocation of the lens in a pocket corresponding in width to the diameter (shape) of the lens is virtually eliminated;

5. Reduced postoperative infectious complications.

Claims (6)

1. A method for implanting an intra-corneal lens, characterized in that an arcuate incision is made in the sclera, in the meridian interval, where there is no attachment of the tendons of the eye muscles, to the penetration depth behind the episclera layer, then a tunnel is created in the sclera and corneal stroma layers in the direction of the optical center of the cornea, where they form a pocket according to the shape of the lens, where it is implanted. 2. The method according to claim 1, characterized in that the arcuate incision in the sclera is carried out in the range of the meridian from 12 to 3 hours 3. The method according to PP.1 and 2, characterized in that the incision in the sclera is carried out to a depth of 200-450 microns. 4. The method according to claims 1 to 3, characterized in that the pocket in the cornea is formed according to the shape of the lens. 5. The method according to claims 1 to 4, characterized in that the lens has the shape of a sphere, cylinder, prism. 6. The method according to claims 1-5, characterized in that the lens is made of a polymer biological material.

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