Keratoprosthetics

Keratoprosthetics refers to the replacement of a damaged cornea with a corneal prosthesis .

The method is used when conventional therapies for the defective cornea such as transplantation of a donor cornea or mechanical processing due to rejection reactions by the immune system or excessive damage to the eye are out of the question.

The first descriptions of keratoprosthetics come from Pellier de Quengsy in 1789 . Gerd Sommer (1906–1988) from Zittau was awarded special services in the development and refinement of keratoprosthetics in Germany .

Procedure

Graded according to the degree of destruction of the eye structure:

Osteo-Odonto Keratoprosthesis

The front part of the severely damaged eye is covered with mucous membrane from the cheek, at the same time a tooth and part of the jawbone are removed and a thin slice is prepared from the center. A hole is drilled in the part of the tooth and a cylindrical plastic optic is attached to it. The prosthesis is then implanted in the cheek to enable the formation of nourishing tissue around the tooth and the piece of bone.

After a few months, the prosthesis is removed and anchored in the eye under the transplanted cheek mucosa, and a hole is prepared for the cylindrical optic. This allows light to reach the retina again. This prosthesis replaces the cornea, iris and lens.

Boston KPro

It is a cylindrical plastic optic that is inserted through a hole in a donor cornea before implantation and then fixed from behind with a thin, perforated titanium disc.

The implant is sutured to the edge of the patient's damaged cornea through the donor cornea "ring" and simultaneously replaces the lens.

Synthetic corneas

There are various approaches for the production of corneal prostheses from plastics. Usually an optical lens is surrounded by a part which is intended to ensure that it grows into an intact eye structure. Known systems are e.g. B. AlphaCor, ArtCornea and TexKpro. In the case of ingrowing systems, implantation almost always takes place under the damaged cornea.

After the prosthesis has grown in, the damaged cornea is then removed over the optical part of the prosthesis.

Sources and web links

N. Schrage, S. Langefeld, T. von Fischern, S. Kompa, H. Drechsler: Overview of the state of keratoprosthetics, experiences with the Aachen keratoprosthesis. Lecture on the occasion of the 99th annual meeting of the German Ophthalmological Society , 2001 in Berlin.
Anselm Kampik, Franz Grehn: Ophthalmological therapy. Thieme, Stuttgart et al. 2002, ISBN 3-13-128411-0 .
M. Jähne: Keratoprosthetics - continuation of a Zittau tradition. In: Clinical monthly sheets for ophthalmology. Edition S 6, Vol. 221, 2004, doi : 10.1055 / s-2004-836993 .