Cutting-edge gene therapy has achieved long-lasting vision restoration in patients with a rare disorder called choroideremia who would otherwise have gone blind, an exciting and newly published study reveals. The genetic disorder strikes young men, whose light-detecting cells begin dying and who were, until now, doomed to gradually losing their eyesight completely.
The gene therapy developed by researchers from the University of Oxford, in which working copies of the defective cells are introduced to the eye, has been proven in a small trial to have the capacity to not only prevent further degeneration, but even to restore the functioning of previously damaged cells and improve eyesight. The new therapy has been conducted on 14 choroideremia patients from the UK as well as 18 others from the US, Canada, and Germany, as detailed in the New England Journal Of Medicine.
What Can The New Gene Therapy Offer?
One in 50,000 people are affected by choroideremia, for which there was previously no treatment at all and which causes complete blindness by time time patients reach their mid life. One patient, Joe Pepper, spoke to the BBC, saying: "I was scared of what would have happened; I was scared of not being able to see or live the life I had. And now to have the belief that that's not going to happen is a weight off your shoulders."
During the trials, two patients experienced marked improvement in their eyesight that was maintained over multiple years. Those who received higher doses did better, while untreated eyes were shown to be affected by a continued decline in vision.
In future, many people like Joe will be able to hold on to their eyesight despite their genetic conditions — the researchers behind the ground-breaking treatment revealed that they believe that, thanks to the remarkable results achieved during these trials, the therapy will be licensed and offered to more choroideremia patients within the next three years.
The lead researcher, Oxford University eye surgeon Robert MacLaren, explained: "The concept of gene therapy is that it corrects gene defects. Ideally, we should only have to do that once, because once the DNA is corrected and inserted into the correct cell, that cell should be able to continue its function as normal. We seem to have achieved this concept of one single treatment that does not need to be repeated which is unlike traditional medicines."
Could The New Gene Therapy Treat Other Forms Of Blindness Too?
The good news doesn't end here, however. Though the gene therapy being available only to patients suffering from choroideremia would be amazing in itself, the research team is going to apply for approval of trials that could treat other, more widely-spread, forms of inherited blindness as well. The gene therapy offers particular hope to people who have macular degeneration, a condition that affects many more people than choroideremia does. Ultimately, the gene therapy the research team developed may have brought us a little closer to a world in which blindness is treatable.