EFN

A team of doctors in the U.S. treated 12 patients who have a rare genetic eye disorder by using gene therapy which significantly improved vision.

Younger patients seemed to react better to the gene therapy, which involves injecting the eye with genetic material on a virus, the research team reported. Six of the 12 patients had so much of their sight restored, that they may no longer be classified as legally blind.

“All 12 patients given gene therapy in one eye showed improvement in retinal function. The effect was stable during follow-up. The results support our hypothesis that the response to subretinal gene therapy depends on the extent of retinal degeneration and, therefore, the age of the patient,” wrote Dr. Jean Bennett, of the University of Pennsylvania School of Medicine in Philadelphia, and colleagues.

More research needs to be conducted that will test the safety of the treatment, its durability and other factors. However, so far, improvement in vision has remained as long as two years after a single treatment without evidence of major harmful side effects.

Among the most serious forms of inherited retinal degeneration is Leber congenital amaurosis (LCA), which is a group of diseases that are caused by mutations in any one of at least 13 genes. Patients with LCA have severe loss of vision and abnormal eye movements in early infancy and during early childhood.

A number of companies are developing gene therapies and 320 trials are under way or cleared to begin by U.S. regulators

The full report can be found in the latest online edition of The Lancet.