Gene Therapy Restores Vision in Both Eyes

Jean Bennett and colleagues at the University of Pennsylvania reported that three women who were born virtually blind now have improved vision through gene therapy. The three patients have Leber's congenital amaurosis, a rare heritable eye disease that destroys vision by killing photoreceptors. One probable cause of this disorder in the mutation of genes in the retinal cells such as the RPE65, which codes for the production of an enzyme that helps break down retinol. In their initial study, Bennett injected a harmless virus carrying normal copies of the RPE65 into the retinal cells of one eye to began producing the enzyme. Six out of the twelve patients showed improvements in their vision.

In their new study, Bennett injected functional genes in the other eye which was left untreated. Six months after the gene therapy, the patients' exhibited great results: " They could navigate an obstacle course, even in dim light, avoiding objects that had tripped them up before, as well as recognize people's faces and read large signs." Aside from improved sensitivity to light, they also observed that the patients' brains were more responsive to optical input as well.

Read more at http://www.scientificamerican.com/article.cfm?id=gene-therapy-blindness.