SU1734725A1 - Keratoprosthesis - Google Patents

Abstract

This invention relates to medicine, in particular to ophthalmology. The purpose of the invention is to increase the strength of the keratoprosthesis. The keratoprosthesis contains the optical part in the form of coaxial cylinders 1 with an external thread, the supporting part 2 made of a tantalum or titanium plate, pressed into the groove 4 of a sleeve having an internal thread. A keratoprosthesis allows replacing only the outer or all layers of the cornea, provides the possibility of multiple unscrewing or screwing up the optical part in order to replace it with another one and to eliminate various complications of corneal prosthetics without removing the support part. 2 Il.

Description

The invention relates to medicine, in particular to ophthalmology, and can be used to restore vision in severe eye disease.

A well-known keratoprosthesis consisting of an optical part made in the form of two coaxial cylinders with a thread on a cylinder of smaller diameter, a supporting part from a plate of titanium with a central hole and a plastic sleeve with an internal thread inserted into this hole.

A disadvantage of the known keratoprosthesis is that the fastening of the plastic sleeve in the hole of the metal plate does not exclude its twisting or axial displacement when screwing or unscrewing the optical part of the prosthesis, since the sleeve is simply inserted into the hole until it stops in the form of an extension of the sleeve at one end.

4 of the invention is an increase in the strength of the connection of the sleeve with the keratoprosthesis support plate.

To this end, in the proposed keratoprosthesis, a groove is made for the metal support part on the outer surface of the cylindrical plastic sleeve, and the metal support plate is pressed into the sleeve simultaneously with the forming of the sleeve.

Comparative analysis allows us to conclude that the proposed device is characterized in that a groove is made in the sleeve on the outer surface for fixing the metal plate, which excludes the possibility of the sleeve shifting and turning when screwing and unscrewing the optical part.

Figure 1 shows the proposed keratoprosthesis; figure 2 - section aa in figure 1.

A keratoprosthesis contains an optical part 1, made in the form of a stepped body, which consists of two coaxial cylinders of different diameters from polymethyl mvacrylate and a supporting part 2 from a titanium or tantalum plate. curved according to the curvature of the cornea, the state of SP

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MSC two coaxial rings connected by three radial jumpers, The edge of the hole of the inner ring is pressed into the sleeve of polymethyl methacrylate 3, having a groove 4, on the outer surface for the support. The inner channel of the sleeve 3 is threaded. For prosthetics of the outer layers of the cornea, the optical part 1 is used, with a cylinder of smaller diameter equal to the length of the sleeve, and for through prosthetics it is 1.5–2 mm longer. On the convex spherical surface of the optical cylinder, there are two turnings for screwing and unscrewing the prosthesis 5.

The keratoprosthesis is implanted as follows.

A cut is made over the limb. The cornea splits into two plates. The outer plate is trepanned with trephine, the diameter of which corresponds to the diameter of the optical cylinder or 1.0-0.2 mm smaller.

The inner plate is thinned in accordance with the trephination opening in the anterior plate to transparent layers. Then the optical part 1 of the keratoprosthesis is inserted into the trepanation hole of the anterior cornea plate, and the supporting part of the prosthesis 2 is placed between the corneal plates and stitched. If the deep layers of the cornea are not sufficiently transparent or dimmed, then by unscrewing the optical part of the prosthesis, you can thin the inner plate of the cornea and screw the same optical part again, or remove the internal plate of the cornea and screw the longer optical cylinder.

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The positive effect of the proposed invention lies in the possibility, depending on the state of the cornea, to replace all layers of the cornea with a prosthesis or to perform a more secure prosthetic procedure only on the outer layers of the cornea.

After implanting the prosthesis, unscrewing the optical part, it is possible to atraumaticly eliminate complications of prosthetics of the outer layers of the cornea (remove the blood that formed the capsule, thin the opaque posterior cornea plate) and remove, if necessary, the back plate of the cornea and move from the prosthesis of the outer cornea to prosthesis without removing the cornea, without removing the cornea without the removal. previously supporting part.

Increasing the strength of the joint between the support part and the sleeve virtually eliminates the possibility of turning the sleeve and its displacement along the axis and provides the possibility of successful multiple unscrewing and screwing of the optical part to be replaced with another and to eliminate various complications of corneal prosthetics.

Claims (1)

Claims of the invention A keratoprosthesis comprising an optical and supporting parts interconnected by a sleeve, characterized in that, in order to increase the strength of the connection between the supporting part and the optical part, a notch for the supporting part is made on the outer surface of the cylindrical sleeve, with the metal supporting part fixed in the sleeve simultaneously with the formation of the latter. Aa Phi. 2