For the first time in humans, gene therapy has been used to restrore sight. The study, at the University of Pennsylvania, was designed to test the safety of the procedure, but the results were much better than anticipated.
The treatment was applied to two patients suffering from Leber’s Congenital Amaurosis (LGA), a rare congenital condition in which the patient’s have severely reduced vision due to the lack of the RPE65 gene, a retinal pigament epithelium specific protein, which is required for the maintenance of the epithelial cells covering photoreceptor cells in the retina.
Estimates showed that light levels after 90 days were increased by a factor of almost 5 orders of magnitude compared to the pre-treated state.
However, this is a treatment for just one type of LGA, which is merely one of many forms of blindness, the causes of which are often much more comlicated in terms of their etiology compared with the current study. Nevertheless, this study demonstrates the applicability of gene therapy as a paradigm to the treatment of both congenital and degenerative forms of blindness.
Nick Rhodes