A blind person can also distinguish objects after an optogenetic treatment

Doctors have used gene therapy to attach a light-sensitive molecule to one of the human eyes. The genus they added, called a crimson, comes from a species of unicellular alga that is able to feel sunlight and move towards it.

The idea of ​​attaching the gene, says Roska, is to engineer retinal cells called ganglia so that they are able to respond to light, sending visual signals to the brain.

The strategy, funded by a French company called GenSight Biologics, requires patients to put on a set of electronic glasses that capture light contrasts in the environment and then project an image onto the retina at high intensity using the same length. specific wave of yellow-orange light triggers the crimson molecule.

A blind patient treated with a new form of gene therapy uses a series of glasses to try to count the objects placed in his field of view. It has an EEG cap so that researchers can measure its brain’s response to light.


According to José-Alain Sahel, a researcher at the University of Pittsburgh who played a leading role in the experiment and is a co-founder of GenSight, the blind man at first had no effect, but began to report seeing shapes while wearing glasses. Sahel describes the patient as “the first to benefit from octogenetics.”

With the training, the man was able to understand if a notebook had been placed on a table in front of him. I could even count the dark-colored cups placed in front of him, even if it’s not always accurate.

Optogenetics is widely used in neuroscience experiments on animals, where light-sensitive molecules are added to brain cells. Then, using light pulses transmitted via fiber optic cables, researchers can trigger specific nerves, in some cases to induce specific behaviors.

Efforts to adapt the technique as a blindness cure began in 2016, when a Texas woman became a blind woman. the first person treated with optogenetics by a small company, RetroSense, which was later acquired by Allergan. The results of that study were never publicly released, although Allergan officials said after some patients he pretended to see light, As he perceives a bright window in a dark room.

See Bio, a startup in Cambridge, Massachusetts, has also developed optogenetic treatments.

According to Roska and Sahel, several patients have been treated in the GenSight-sponsored clinical trial, but only the man whose case is described today has worn glasses.

The level of vision restored to the patient remains very limited. What you see through googles is monochrome, and the resolution is not high enough to read, or even to distinguish one object from another.

Researchers said the glasses could be refined and that, with higher training, the man might be able to see more of what he is doing now. “The level of vision we’re going to reach is impossible to predict,” Sahel says.

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