For the first time, scientists have used gene therapy to successfully reverse blindness in mice suffering with an inherited condition, which causes people to lose their sight over time.
Researchers at the Nuffield Laboratory Of Ophthalmology, have shown that it is possible to use gene therapy to reprogram the retina nerve cells at the back of the eye to become light sensitive again.
The subjects in the study were all afflicted with Retinitis Pigmentosa, the name given to a group of inherited conditions of the retina, which are the most common cause of blindness in young people.
Affecting approximately 1 in every 3,000 to 4,000 people in the UK, the condition begins with a deterioration in night vision and peripheral vision, and later affects reading, colour, and central vision.
In order to counteract this lifelong condition, Samantha de Silva and her colleagues used a viral vector – a tool which can deliver genetic material into cells to modify a specific cell tissue and express therapeutic genes.
In this cause to express a light-sensitive protein, melanopsin, and reprogram the damaged cells to send visual signals back to the brain.
The trial resulted in mice maintaining their vision for the entire year after the procedure, being able to recognise detailed objects in their environment, something which indicated a high level of visual perception.
Samantha de Silva, the lead author of the study said: ’There are many blind patients in our clinics and the ability to give them some sight back with a relatively simple genetic procedure is very exciting.”
The next step would be to start a clinical trial for this method in patients, 50% of whom have family members with the condition.
The Oxford-based team has also been trialling an electronic retina successfully in blind patients, but the genetic approach may have advantages in being simpler to administer in the long term.