The gene therapy experiment successfully restored partial vision in individuals suffering from hereditary blindness, as some were able to distinguish light and better locate objects after treatment.
According to the New England Journal of Medicine, the tests included ten individuals diagnosed with retinitis pigmentosa—a hereditary disease in which the retinal cells responsible for light perception gradually deteriorate. All participants essentially experienced total vision loss.
The tests involved injecting a specific gene into the patients' eyes, making the remaining retinal cells sensitive to light. This procedure was carried out using optogenetics. After the procedure, participants wore special glasses equipped with a camera that transformed the surrounding image into light signals received by the modified cells.
The results of the treatment showed improved light sensitivity in seven out of ten patients, with six of them experiencing clinically significant improvement. Additionally, some participants became better able to notice objects, pinpoint their locations, and access them more accurately. This improvement persisted in four patients for months and even years. A brain activity study indicated that the visual cortex received and processed visual information. This means that even after prolonged vision loss, the brain remains capable of perceiving new visual signals.
However, according to the researchers, the patients did not fully regain their sense of sight, as they remained unable to see or read normally.