Gene therapy helps people with monochrome vision to see in color

Color blindness is usually a hereditary condition. While there have been a few high-tech methods, such as special glasses, to help people deal with it, to date there hasn’t been much in the way of a permanent solution to the problem. Perhaps until now, that is.

An initial trial in patients suggests that a new gene therapy treatment for helping overcome color blindness, developed by researchers in Germany, is completely safe. The researchers also obtained evidence that the treatment works.

The condition in question, referred to as achromatopsia, is one of the rarer types of color blindness. Approximately 8% of men and 0.5% of women have some kind of color blindness which renders them unable to see certain colors (red-green color blindness being the most common). Achromatopsia, however, affects just 1 out of 33,000 people — which nonetheless adds up to a sizable cohort of people worldwide. The condition is due to non-functioning or absent retinal cones, and it makes the world appear entirely black and white. It also causes blurred vision and makes eyes extremely sensitive to bright light.

In around one-third of patients with achromatopsia, the condition is caused by a gene called CNGA3. The new treatment, developed by researchers at the Institute for Ophthalmic Research at the University Hospitals in Tübingen and Departments of Pharmacy and Ophthalmology at Ludwig Maximilian University of Munich, makes it possible to inject a corrected version of the gene into a patient’s retina using a harmless virus.

A trial involving nine achromatopsia patients, aged between 24 and 59, was recently carried out at the University Eye Hospital Tübingen. There were no health issues, and the retina suffered no permanent change or damage as a result of the procedure. Patients involved in the study saw their vision improve in terms of focus, contrast perception, and — most crucially — color vision.

“The study is an important first step,” Martin Biel from the Department of Pharmacy at LMU, said in a statement. “It represents a milestone on the road to a curative therapy of achromatopsia, and we expect even better treatment success in the future.”

A paper describing the research was recently published in the journal JAMA Ophthalmology 2020.

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