Eye biosynthetic cornea developed

Eye: Biosynthetic cornea developed.

(27.08.2010) Swedish researchers have synthesized a cornea from artificial collagen tissue by biosynthesis. Ten patients have already successfully transplanted the novel implant, with six of them seeing significant improvement in vision.

The cornea, which sits on the surface of the eyeball, performs essential functions in the refraction of light and determines, among other things, the eyesight of a person. However, directly on the surface, the cornea is also prone to injury, infection and other conditions that can damage or cloud it. If it is damaged, the visual acuity decreases considerably and in some cases a total loss of vision follows. The affected person can often only be helped by the transplantation of a healthy cornea, whereby previously the cornea of ​​the deceased was mostly used. However, there is a lack of donors to meet existing needs. For example, the process of producing an artificial collagen cornea offers good reason for hope for many patients who have been waiting for surgery for years.

Approximately 4,000 corneal transplants are performed each year in Germany, whereby artificial plastic tissue has also been transplanted in the past. Now developed by the researchers of the Swedish University in Linköping, the method takes advantage of the natural properties of the eye and leads to better results. They use the natural structure of the cornea, which consists for the most part of lattice-like crosslinked collagen fibers that are covered on both sides (top / bottom) by one cell layer each. By surgery, the doctors removed only the damaged cornea and replaced the collagen-containing portion by a synthetic counterpart. In the previously treated patients, the eye responded by rebuilding the cell-containing areas around the implant. Two years after the operation, the biosynthetic tissue was fully integrated into the eye, functional and even sensitive to touch, says study leader Per Fagerholm.

In nine of the ten patients, even the severed nerves re-grew into the new tissue, and six of them experienced a significant improvement in their vision, the researchers added as they presented their findings in the journal Science Translational Medicine. Two operations, however, also resulted in a deterioration of vision, which had to be compensated with contact lenses.

Nevertheless, the advantages of the procedure are obvious to the Swedish scientists around Per Fagerholm: no danger of transmission of pathogens and no risk of a rejection reaction by the immune system. And from the researchers' point of view, the results could still be improved if, during the operation, no sutures were used, but, for example, a biological adhesive to promote the healing process. In general, however, the results are already quite comparable to those after corneal transplantation, explained Per Fagerholm. Accordingly, the researchers are convinced that they have discovered a real alternative to conventional corneal transplantation. (Fp)