Neuroscience: Seeing the light with visual prostheses

Rats with prosthetic retinal implants display visual responses to light, a study in this week’s Nature Communications reports. The rats elicit responses in the part of the brain responsible for visual processing, when the prostheses are stimulated by light.

In recent years, research into photovoltaic visual prostheses with the potential to restore vision for blind individuals has gathered pace, and while they have been shown to be useful in stimulating retinal tissue, their usefulness in restoring sight has not been assessed. Yossi Mandel and colleagues implant visual prostheses into rats with degenerate retinas and then record neuronal responses from the visual cortex in the brain as a measure of sight restoration. They find that visual cortex responses can be evoked in response to light stimulation that is similar to the stimuli used for earlier studies that examined the effectiveness of these devices to stimulate retinal tissue. The authors acknowledge that more studies would be needed to determine just how successful these devices are in restoring full vision, but they hope that these studies will provide encouraging reassurance in the feasibility of photovoltaic approaches for retinal prostheses.

Retinitis Pigmentosa and age-related macular degeneration are two of the leading causes of blindness in the Western world. While some treatments can delay the progression of these diseases in some individuals, there are currently no known cures available.