Breakthrough: gene therapy returns vision to completely blind mice

Nanoscope reported success in using gene therapy to partially return vision to completely blind laboratory mice. The developed method is universal and, apparently, has no side effects. But there is a catch - scientists cannot assess the effectiveness of the animals' vision, how functional it is. Therefore, experiments on humans are coming.

In ophthalmology, it is not uncommon for the eye to be healthy as a whole, its neural part regularly transmits a signal to the brain, but this signal itself is not generated, because the photoreceptors of the eye have died. They are located on the outside of the retina and capture light to convert it into a chemical signal and transmit it to bipolar cells, which convert it into a neural signal. Photoreceptors are extremely vulnerable, both to injuries and to diseases, and they are often ruined by age-related degradation.

The idea of ​​the biologists at Nanoscope is that it is possible to create an artificial chemical signal by triggering the generation of the corresponding opsin proteins already behind the photoreceptor. To do this, they used the AAV2 carrier virus to deliver the opsin activator gene MCO1, which was injected into the retina through a single injection. For six months, the experimental mice showed no pathologies - such an intervention did not harm them.

As for the restoration of vision, there are many questions. On the one hand, in initially blind mice, the eyes returned to work, which was confirmed by visual tests and increased general activity. On the other hand, mice see light, this is a fact, but what details does their brain distinguish? Yet the artificial generation of opsins is not the same as their production in photoreceptors under the influence of light. Since mice cannot tell what they are seeing, Nanoscope has scheduled its first experiments with people with severe retinal disease at the end of the year.