Corneal Prosthesis Offers New Hope for Those Blinded in Accidents

A novel hydrophobic polymer material is being used to manufacture a synthetic eye prosthesis that could offer patients that cannot receive a donor cornea a further option for corneal transplantation.

Researchers at the Fraunhofer Institute for Applied Polymer Research (IAP; Potsdam-Golm, Germany) developed the eye prosthesis jointly with physicians and manufacturers participating in the European Union Artificial Cornea project. The first stage involved a common hydrophobic polymer that is coated along its edge with a specific sequence of a growth factor (GF). The surrounding natural cells detect this GF, and are stimulated by it 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. The polymer, which is commercially available, repels water, so it will not absorb tear-duct secretions that could cause it to swell. It also prohibits cell growth in the central region, so natural tissue will not cloud it over.


The chemical-biomimetic coated implant was then sent to Regensburg University Medical Center (Germany), and to the medical center at the Technical University of Munich (Germany), where they were tested in dissected pigs eyes and specialized cell cultures. Eventually, the artificial corneas were tested in-vivo in rabbits; the design was further refined, the optics were reduced, and the implant haptic enlarged in order to maintain a more stable construction. The total development time took three years. The artificial cornea went into production in 2009 by Miro (Siegen, Germany), and the first in-human implantations began during the first six months of 2010.

"The new artificial cornea adheres to eye cells without needing to be held in place by sutures - a major advantage over other artificial corneas, which can cause inflammation and infection,” said Joachim Storsberg, Ph.D., head of functional medical polymer research at the IAP.

Corneal transplantation is a surgical procedure in which a damaged or diseased cornea is replaced in its entirety (penetrating keratoplasty) or in part (lamellar keratoplasty). The donated corneal graft is removed from a recently deceased individual with no known diseases or other factors that may affect the viability of the donated tissue, or the health of the recipient. There is a constant shortage worldwide in available corneal donor grafts.

Related Links:
Fraunhofer Institute for Applied Polymer Research
Regensburg University Medical Center
Technical University of Munich
Miro