Two Swedish research teams have tested a new gene therapy that improves vision in people with an unusual hereditary eye disease, Bothnia dystrophy. Twelve people have tested the treatment – eleven of them experience improvements.
– Large light differences are difficult, but now I can see better when I go from strong light outside and into a building, says Sören Lundgren from Umeå.
Sören Lundgren in Umeå has the hereditary eye disease Bothnia dystrophy, which causes both loss of vision when it is bright and major problems with night vision.
– If I come from outside and enter a building or a bus, my eyes cannot adjust to the difference in light, it becomes very dark, says Sören Lundgren.
Marie Burstedt, senior physician and researcher at Umeå University, was the one who found the defective gene that causes the disease.
– For an ordinary adult, it can take fifteen minutes to adapt, for these patients it can take six to eight hours, she says.
May lead to blindness
The disease begins with poor night vision and ends with severe visual impairment or blindness. Most of those affected are in Newfoundland in Canada and in Västerbotten. It may be due to a gene variant that is only found in these areas.
So far there is no treatment, only aids. Dark lenses have been shown to be able to slow down the disease as the differences between light and dark become smaller.
But now twelve of chief physician Marie Burstedt’s patients have had gene therapy tested. The researchers at the Karolinska Institute have injected a virus under the retina of the eye that contains a correct gene to replace the broken one, and the result has been positive.
– In eleven of the patients there was a clear improvement in visual function and night vision, says Anders Kvanta, professor of eye diseases at Karolinska Institutet.
Difficult to finance – studies are paused
The study has been company-financed, but now the company has paused the work. Only around 10,000 patients in the world mean that further development can be difficult to finance.
– For the sake of the patients and for me as well, it would be very sad if there were no continued development. But that is the reality we live in, pharmaceutical companies also have to make money from their medicines, so I have a certain understanding of that, says Anders Kvanta.
The treatment has improved Sören’s vision and he hopes that there will be a drug that can slow down the progress.
– It would be good for young people who still have much of their sight left, it could help them quite a lot, says Sören Lundgren.