Corneal prosthesis, boon for those blinded in accidents

LONDON - For many patients, who become blind after an accident or illness, a corneal transplantation could restore their ability to see.

Each year, 40,000 people in Europe - in Germany, about 7,000 - await the opportunity to be able to see again, thanks to cornea donors. But cornea donors are not common.

Joachim Storsberg of the Fraunhofer Institute for Applied Polymer Research IAP in Potsdam-Golm, developed material and production process for a corneal prosthesis made of plastic.

The miniscale artificial cornea has to meet almost contradictory specifications: On the one hand, the material should grow firmly together with the cells of the surrounding tissue.

On the other hand, no cells should settle in the optical region of the artificial cornea - i.e., the middle - since this would again severely impair the ability to see.

And the outer side of the implant must be able to moisten with tear fluids, otherwise the implant will cloud up on the anterior side. This would consequently require the patient to get a new prosthesis after a relatively brief period of time.

In order to achieve the desired characteristics, the edge of the implant was first coated with various, special polymers.

Then, a special protein was added that contains the specific sequence of a growth factor. The surrounding natural cells that detect this growth factor are stimulated to propagate and populate the surface of the corneal margin.

Thus, the cells of the surrounding tissue grow with the implant, and the artificial cornea attains stability, said a Fraunhofer Institute release.

The eye prosthesis was evolved jointly by physicians and manufacturers in the EU project, “Artificial Cornea”.