Hope for corneal blindness

People suffering from corneal blindness are to be given a second chance at sight, thanks to an Australian bio-medical eye company which has developed an international first – an artificial cornea.

Argus Biomedical Pty Ltd. was recently given approval by the US Food and Drug Administration (FDA) to sell the first soft artificial cornea, the AlphaCor, in the United States.

The FDA endorsement complements regulatory approval for AlphaCor in Europe, Canada and Australia, and a product development program which commenced in 1989.

The cornea is the transparent circular part in the front of the eyeball and the AlphCor device is designed to replace a diseased or damaged cornea or failed human graft. Its dimensions, flexibility and optics allow it to be implanted and to perform in a manner similar to a donor cornea graft.

The AlphaCor model is made of a biocompatible type of soft plastic, which negates the need for immunosuppressant medications which are usually required with human donor tissue.

The artificial cornea looks like a clear donor cornea graft with a visible spongy rim. The patient’s own cells grow into this outer rim, holding it in place and allowing the eye to function normally. The design is soft and flexible and as a result, the surgery needed to implant it is relatively invasive.

Argus Biomedical Pty Ltd. is a private company marketing AlphaCor which it developed in conjunction with the Lions Eye Institute of Perth, Western Australia.

Dr. Geoffrey Crawford, a surgeon and associate professor of the Institute of Perth, said accidents or diseases damaging the front of the eye could cause corneal blindness.

"When the rest of the eye functions fully, the replacement of the clear window at the front of the eye (the cornea) is all that is needed to restore sight," he said.

"Four years of extensive clinical trials experienced a visual improvement which enabled them to be reclassified from legally blind to functionally sighted," Crawford said.