Restoring Sight to the Blind

Doctors recently reported success at restoring partial vision in a patient who had been blind for nearly forty years. Part of a Phase I safety trial that began in 2018, this case represents the first published study of using optogenetics to partially restore vision in humans.

The participant had lost his sight to retinitis pigmentosa (RP), a genetic disorder in which the light-sensitive cells in the retina break down. Researchers engineered genes that would stimulate the retina to produce light-sensing proteins commonly found in algae and injected them into one eye. The subject was then fitted with special goggles that capture images of the surroundings and translate them pixel by pixel into a monochromatic video signal that can be projected onto the retina.

The participant was unable to visually detect objects before injection, or even after injection, without the use of the goggles. However, after treatment, and with the use of the goggles, he was able to perceive, locate, count and touch a variety of objects. Electroencephalographic (EEG) recordings also indicated evidence of visual changes in the occipital cortex – the visual processing center of the brain. All of this points to the use of optogenetics as a promising therapy for restoring vision in individuals with advanced RP.