SUNDAY, May 3, 2015 (HealthDay News) -- A new study finds that gene therapy quickly improves eyesight for patients who've lost their vision from an inherited condition called Leber congenital amaurosis (LCA).
But the improvements aren't permanent: Researchers said the gains began to diminish after one to three years.
"Gene therapy for LCA demonstrated we could improve vision in previously untreatable and incurable retinal conditions," study leader Dr. Samuel Jacobson, of the University of Pennsylvania's Scheie Eye Institute, said in a U.S. National Eye Institute release.
"Even though the current version of the therapy doesn't appear to be the permanent treatment we were hoping for, the gain in knowledge ... is an opportunity to improve the therapy so that the restored vision can be sustained for longer durations in patients," Jacobson added.
Scientists started the research in 2007, looking at 15 people with the eye condition who received injections of a virus that carried certain genes.
"Within days of the injections, some patients reported increases in their ability to see dim lights they had never seen before," Jacobson said. "It was remarkable for us to get this feedback that things were indeed changing positively."
Dr. Paul Sieving, director of the National Eye Institute, said that six years of data shows that a gene-therapy approach is safe and successfully improves vision in people with LCA.
"As with any application of a novel therapy, it now needs to be fine-tuned. More research is needed to understand the underlying biology and how we can preserve or restore photoreceptors for a lifetime," he said.
The study was published online May 3 in the New England Journal of Medicine.
For more about Leber congenital amaurosis, try the U.S. National Library of Medicine.