Researchers from the UCL Institute of Ophthalmology and Moorfields Eye Hospital NIHR Biomedical Research Centre have announced results from the world's first clinical trial of a revolutionary gene therapy for a type of inherited blindness.
Results from the trial, published on Monday, showed the treatment can improve vision and caused no side effects. The trial was carried out on three patients suffering from Leber's congenital amaurosis caused by an abnormality in gene RPE65. The treatment involves inserting healthy copies of the missing RPE65 gene into the cells of the retina to help them function normally. The healthy genes were delivered to the retina using a harmless virus called a vector.
James Bainbridge, who led the surgical team, explained that they used a very fine needle to deliver the modified virus in a controlled retinal detachment that resolved as the vector was absorbed.
'It is tremendously exciting that this technique is safe in an extremely fragile tissue and can improve vision in a condition previously considered wholly untreatable,' Bainbridge said.
The clinical trial, which began in February 2007, resulted in one of the patients benefiting from significantly improved night vision. This was demonstrated by his ability to negotiate a simulation of a night-time scene quickly and without mistakes, something he had been unable to do prior to the surgery. The other two patients achieved levels of vision at least equivalent to before the operation, but their vision may yet improve.
Professor Robin Ali, who led the trial, said: 'Showing for the first time that gene therapy can work in patients with eye disease is a very significant milestone.
'This trial paves the way for the development of gene therapy approaches for a broad range of eye disorders.'