The American Academy of Ophthalmology reports on a new form of FDA-recommended treatment being researched relating to hereditary blinding retinal disease, and how they might finally be cured through the use of gene therapy.
These treatments would target mutations in the RPE65 gene which has been known to cause early onset blindness in those affected from Leber’s congenital amaurosis, retinitis pigmentosa, and other conditions. Using laboratory-manufactured genes, they would be introduced into a patient (sometimes by a special kind of virus) to replace defective or missing genes causing a retinal disease.
Eyes are an especially good organ to test gene therapy with, as they are both easy to access and “immune-privileged”. This means that, because of an eye’s unique location on the body, it is far less likely to reject new cells implanted into it than with other types of transplants, such as with a kidney or liver.
So far, tests have been fairly positive. 65% of subjects administered LUXTURNA (voretigene neparvovec) showed vision improvements enough to be considered significant, gaining the ability to navigate a maze in low to medium lighting conditions, as well as gaining a better sense for light overall and improved peripheral vision. Additionally, the control group found that none of the individuals who did not receive the gene therapy treatment did not gain any of these benefits, nor could they navigate the maze. 89% of those who received treatment after the conclusion of the experiment, however, did begin to see improvements in their vision.
As of two years since the study was conducted, all the patients that saw improvements have kept those improvements. Researchers do not know if this will change at some point, though, or when this change could possibly happen. Even so, the initial results are striking enough to offer a substantial hope to those at risk for inherited retinal diseases, and may open the door for possible treatment options in the future for more rare diseases, too.