Image credit: Prof Robert MacLaren
The trial involved 14 patients receiving a single injection into the back of the eye of a virus containing the missing gene and began in 2011 at the Oxford Eye Hospital - part of the Oxford University Hospitals NHS Foundation Trust. By the end of the study there was a significant gain in vision across the group of patients as a whole.
Furthermore, of the 12 patients who received the treatment without any complications, 100% either gained or maintained vision in their treated eyes, which was sustained for up to 5 years at the last follow up. During this time only 25% of the untreated eyes which acted as controls maintained vision. The gene therapy treatment was generally well tolerated and there were no significant safety concerns.