Gene therapy restores sight in blind dogs

Philadelphia -- U.S. medical scientists have found gene therapy might be successful in restoring sight in some people even if they have been blind since birth.

University of Pennsylvania researchers used a canine model to demonstrate gene therapy is effective in restoring retinal activity to the blind, as well as restoring function to the brain's visual center, a critical component of seeing.

"The retina of the eye captures light but the brain is where vision is experienced," said Assistant Professor Geoffrey Aguirre, who led the study. "The traditional view is that blindness in infancy permanently alters the structure and function of the brain, leaving it unable to process visual information if sight is restored. We've now challenged that view."

The researchers used functional MRI to measure brain activity in blind dogs born with a mutation in gene RPE65, an essential molecule in the retinoid-visual cycle. The same mutation causes a blindness in humans called Leber congenital amaurosis. It is the first human eye-retinal disorder slated for gene therapy.

The study was reported in the journal PLoS Medicine.

Copyright 2007 by United Press International.