Gene therapy in one eye improves vision in both

An international research team has reported that gene therapy in a group of 37 patients with Leber hereditary optic neuropathy resulted in bilateral improvement of vision – despite the fact only one eye was injected.

The study, which was published in Science Translational Medicine, found that more than three quarters of treated patients experienced significant visual improvement in both eyes.

Dr Patrick Yu-Wai-Man, from the University of Cambridge and Moorfields Eye Hospital, highlighted that researchers expected vision to improve only in the eyes that were treated with gene therapy.

“Rather unexpectedly, both eyes improved for 78% of patients in the trial following the same trajectory over two years of follow-up,” he said.

A follow up study in monkeys found evidence suggesting that viral vector DNA from the injected eye was transferred to the anterior segment, retina and optic nerve of the non-injected eye.

The authors concluded that this “supports a plausible mechanistic explanation for the unexpected bilateral improvement in visual function after unilateral injection.”