Gold and titanium nanowires restore vision in blind mice

To prove what at the beginning of their research was just a theory, the scientists first had to alter the mice’s genes so, as it happens in humans, they degraded. Then, they implanted the metallic receptors in the same space that the photoreceptors once occupied, so that they would remain in physical contact with retinal cells to pass along electrical impulses to the visual cortex.

The nanowires studded with gold flakes were implanted in a few mice at a time and the scientists watched as their subjects began responding to green, blue, and ultraviolet light. The animal’s pupils dilated, which confirmed the new photoreceptors were working or, in other words, that the missing links between the eyes and the brain were repaired.

Retina-nanowire interfaces. a Illustration of an eye. b Comparison of a retina and NW arrays-interfaced blind retina that lacks photoreceptors. Image by Tang et. al.

“Neurons in the primary visual cortex respond to light after subretinal implant of nanowire arrays. Improvement in pupillary light reflex suggests the behavioral recovery of light sensitivity,” the study reads.

No side effects were observed during the eight weeks the mice had the photoreceptors in.

Even though -and for obvious reasons- they couldn’t determine what the mice were seeing, how clear their vision was and restore full-coloured vision, the researchers say that the advances they made are very important for people suffering from retinitis pigmentosa and macular degeneration, which can lead to permanent vision impairment if left untreated.

“Our study will shed light on the development of a new generation of optoelectronic toolkits for subretinal prosthetic devices,” the paper states. It is expected that future tweaks to their method would help see colours.