The finding, reported Tuesday (May 23) in the online journal Public Library of Science-Medicine, proves in principle that a similar treatment can be developed for an incurable form of childhood blindness.

"We were able to restore function to the photoreceptor cells in the retinas of an avian model of a disease that is one of the more common causes of inherited blindness in human infants," said Sue Semple-Rowland, Ph.D., an associate professor of neuroscience with UF's Evelyn F. and William L. McKnight Brain Institute. "The vision capabilities of the treated animals far exceeded our expectations."

The bird -- a type of Rhode Island Red chicken -- carries a genetic defect that prevents it from producing an enzyme essential for sight. The condition closely models a genetic disease in humans that causes Leber congenital amaurosis type 1, or LCA1. About 2,000 people in the United States are blind because they have a disease that falls in the LCA family.

"Enabling chickens that can't see to peck and eat after treatment is stunning," said Dr. Jean Bennett, a professor of ophthalmology and cell and developmental biology at the University of Pennsylvania who was not involved in the study but who participated in a landmark gene transfer experiment five years ago that restored vision to blind Briard dogs. "This is proof of concept using a unique vector, animal model and approach. One would hope this could happen in a human."

Semple-Rowland, a College of Medicine faculty member, has worked since 1986 to first discover the malfunctioning gene, known as GC1, and then to develop a viral therapy to treat it.

"I will always remember the first animal that we successfully treated," said Semple-Rowland, who is also a member of the UF Center for Vision Research and the UF Genetics Institute
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Contact: John Pastor
jpastor@vpha.health.ufl.edu
352-273-5815
University of Florida
22-May-2006