Donor corneas are extremely rare, but for 40,000 people in Europe corneal transplantation from donors offer the only hope of addressing blindness in one or both eyes. That was, until Dr. Joachim Storsberg of the Fraunhofer Institute for Applied Polymer Research IAP in Potsdam-Golm created the first artificial cornea, which has been successfully trialed and has been in use now since 2009. For this contribution to medical science, Dr. Storsberg has been awarded the 2010 Joseph von Fraunhofer Prize.
The specifications for a synthetic cornea are precise: the synthetic material must bond with the cells of the surrounding tissue, but it must not bond in the middle optical region of the artificial cornea. The outer side of the cornea must moisten with tear fluids and allow the eyelid to slide across without friction. Any deviation from these specifications would decrease the effectiveness of the cornea, impair sight, and perhaps require a new prosthesis after a short time.
The cornea was produced from a hydrophobic polymer material that is commonly used in ophthalmology – however it required some developments to be effective for the purpose. Chemically it was altered, modified and re-tested according to medical standards before under-going the physical alterations to meet the specifications. First the edge of the implant was coated with various polymers, then a protein added with a specific sequence of a growth factor. The natural cells in the eye are stimulated by the growth factor to propagate and populate the surface of the artificial cornea in the specified regions. From this point the normal tissue will grow with the prosthesis.