In The Past 40 Years, People Who Have Lost Their Sight Have Partially Recovered.

2021-05-24   |   by CusiGO

For 40 years, a virus carrying the photosensitive algal protein gene and a special kind of amber glasses have been injected into the eyes, restoring vision to the blind. Vision recovery is reduced and the results are very preliminary, but this is the first time such a complex, almost science fiction treatment has been successfully applied to the human eye.

The patient, a 58 year old Frenchman, has been suffering from retinitis pigmentosa since he was no longer a child. This hereditary disease leads to the gradual degeneration of photosensitive eye cells and photosensitive cells (mainly cones and rods). The problem usually starts with so-called night blindness, and then the field of vision shrinks until it looks like it’s going through a small tube. Finally, the people affected only perceive light, that’s all. Although many are still in the middle stage, the Gaul citizen is in the final stage of retinitis pigmentosa.

At the end of 2019, seven patients with retinitis pigmentosa were selected as the pioneer study. They want to test the safety and tolerance of photogenetics based treatments. The technology is only 15 years old and has not yet left the laboratory. Its purpose is to develop or identify photosensitive proteins, proteins that can be activated or turned off by light. So far, they have made the biggest progress in neuroscience, questioning the future of hypothetical mind control. At the vanguard, they want to use photosensitive proteins extracted from seaweed. They are rhodopsin, which in humans absorbs light and converts it into electrical signals.

Because of the pandemic, they only tested the algae rhodopsin on the patient who is the protagonist of the story. Jose Alain Sahel, director of the Institute of vision at the University of Sorbonne in France and co-author of the study, said the trial would continue with other patients once the covid passed. The first study will include about 15 They will be recruited from France, the UK and the US.

As Sahel and his colleagues detailed in the journal Nature Medicine, they had to allow another element in the retina to capture light without a surgical stick. They looked at ganglion cells. They are neurons that end up in the brain, receiving information from cones and crutches in the form of electrical signals, and sending it to the visual cortex. To make them photosensitive, genes have to be extracted from these algae, which, once inside these cells, encode rhodopsin. They used adenovirus as a vector and injected it into the retina. This part of the system is already familiar: it’s the input method of some coronavirus vaccines, such as AstraZeneca or satellite v.

After giving the foreign gene about four months to stabilize the production of rhodopsin, the researchers began training the French patient. In seven months, he had to conduct nearly 100 tests, in which he found a series of items (a notebook, several glasses and a box of dark staples) on a white table. Some tests are done with special glasses.

Tests show that patients can locate, touch and count items on the table, but only when wearing glasses. In other words, eye injection alone is not feasible. Botond Roska, a researcher at the Institute of clinical and molecular ophthalmology in Basel, Switzerland and co-author of the study, explains why: “light sensors cannot adapt to different lighting conditions and need more light than is available in the room.” In addition, the rhodopsin of these algae is particularly sensitive to the amber range So the camera on the glasses is adjusted, and the projector on the glasses provides a high enough level of amber light for the optical genetic sensor to work, “Roska said.

Of the 39 tests, 36 (92%) were wearing glasses to touch the notebook. As for glassware, he counted it correctly 63% of the time. The biggest problem he encountered was the stapler box, which he touched correctly in only a third of his attempts. Outside of the experiment, subjects reported finding other everyday objects, such as plates, telephones, furniture or doors. In the street, he can distinguish the stripes of zebras. In the final experiment, they measured the activity of the visual cortex of patients as they placed objects on a table. So they confirmed that their photogenic system is active in the visual cortex.

For Jaume catala á, an ophthalmologist at St. Joan dedu hospital and belwich hospital in Catalonia, the results of the study “are good news and influential.”. Although other similar experiments are underway, this is the first time to show the feasibility of human photogenetics. If it wasn’t for a pandemic, the sample size would be much larger. ” The advantage of this approach is that it is independent of mutations and can be applied to patients with a lack of functional photoreceptors, “added rare retinal disease expert catal á.

There is no treatment for retinitis pigmentosa. As Eduardo fern á ndez of the Institute of bioengineering at Miguel Hernandez University puts it, “all we can do is do genetic diagnosis to determine who will have it.” That’s why you think the results of this work are very relevant. But, he added, “they were also very preliminary, and the subjects basically saw the mass.” For Fernandez, just as he emphasized the importance of this research, it is important not to have false expectations: “blind people will wait longer and believe that they will see things like you or me, which is still very important.”

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