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Partial vision restored for blind men thanks to optogenetics


Optogenetics technology is combined with glass that produces amber light

Sahel et al, Nature Medicine and StreetLab / Institute de la Vision

Blind men have recovered from flickering vision thanks to high-tech treatments that use optogenetics, which genetically alter nerve cells to respond to light.

French company GenSight Biologics We publish results showing that the first recipients of the treatment can recognize different objects in lab tests. “It’s exciting to see the first publication on human optogenetics,” he says. Ed Boyden Co-inventor of optogenetics at the Massachusetts Institute of Technology in Boston.


Optogenetics It has become a widely used lab tool because it can accurately control brain cells by changing them to fire in response to light. There are many discoveries about the brain when used in animals, but the medical potential for treating people’s brain disorders is limited because fiber optic cables need to be embedded to get light into the head. It is being considered.

However, because the nerve cells in the eye are exposed to external light, some groups are trying to develop it as a treatment for blindness. One of the targeted conditions is retinitis pigmentosa. This is a hereditary disease in which the retina, the disk of tissue behind the eye, gradually deteriorates and photodetective cells die.

GenSight’s treatment involves injecting genes originally found in algae into nerve cells below the photodetector layer and firing them in response to amber light. To be able to see, the recipient must wear goggles with a camera and processor that turns normal light into an amber wavelength and boost the signal so that it can be detected in the modified cell. ..

The first person to receive this treatment, a 58-year-old man from Brittany, France, discovered about a year later that he saw black and white stripes on a pedestrian crossing on the road.

Since then, he has been able to perceive objects such as telephones, furniture, and hallway doors. In lab tests, he was able to count and find objects in front of him, but he could not recognize his face.

José-Alain Sahel of the Paris Vision Institute, working with the GenSight team, could improve men’s vision even further as the brain takes time to learn to process abnormal signals from the eyes. “Probably what’s happening is a remodeling of the retina-brain connectivity,” he says. Goggles also need to be adjusted in the lab while the wearer is being trained, which was interrupted by the covid-19 pandemic.

The two in the UK are receiving the same gene therapy but have not yet been trained, so their eyesight has not improved yet. Recently, four people received higher doses. The team hopes this will bring greater benefits, Sahel says.

According to team members, in its current form, this approach may not provide sufficient eyesight to read and recognize the face. Botton Roska At the Institute for Molecular Clinical Ophthalmology in Basel, Switzerland. “For that, we need a very high resolution.”

U.S. companies Bionic siteReported in March that four blind or nearly blind people were able to perceive the light and movement of objects in front of them thanks to optogenetic treatment, but the science of these discoveries. The paper has not been published yet.

Bionic Sight treatments provide different genes than GenSight treatments and require Press releaseAccording to Bionic Sight, two people who received high-dose gene therapy were more photosensitive than the other two.

Even the slightest improvement in vision can have a significant impact on people who are almost blind, he says. Michelle Michaelides The University College London is developing another type of gene therapy for the visually impaired.

However, he adds, targeting people with severely deteriorated retinas, as done here, means that it may be difficult to bring them back to full vision. “There is a big challenge in this area, but this is a gap in the light.”

Journal reference: Nature medicine, DOI: 10.1038 / s41591-021-01351-4

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Partial vision restored for blind men thanks to optogenetics

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