Researchers at the University of Oxford used gene therapy to restore sight to 12 patients with choroideremia. It is a rare genetic disease that causes a progressive blindness. Those who suffer from it are destined to lose their sight before the age of 40. The first test for the new treatment, however, worked: the degeneration stopped and there was a significant increase in vision.
The first tests began in 2011. The disease is caused by mutation in a single gene, which treatment is targeted. The doctors mounted a correct version of the gene on a viral vector and injected it into a patient's eye. The virus has infected cells, replacing the wrong gene with a correct copy. For years after treatment, patients have shown a marked improvement in the treated eye and a worsening in the untreated eye.
It is estimated that only in Italy there are a thousand people suffering from choroideremia, but they could be even more. It is possible that the lack of treatment and the rarity of the disease prevented the diagnosis in many cases. Ophthalmologists are not prepared for the possibility that the deterioration of peripheral vision is caused by a genetic disease.
This first test was an important success in the fight against choroideremia, which today is not a cure. If confirmed with other clinical trials, it could save the sight of thousands of people in the world. For the moment it is known that the procedure is safe. The next step will be to test it on more patients and confirm its effectiveness.