Optogenetics Reverse the Decay of Retina Cells to Restore Sight

blind Scientists have partially restored sight in blind mice using a protein to repair damaged cells in the retina. These experiments may ultimately lead to treatments that restore sight in patients with progressive degenerative retinal diseases such as diabetic retinopathy, retinitis pigmentosa and macular degeneration.

The research at the University of Bern in Switzerland and the University of Göttingen in Germany used “optogenetics,” which involves utilizing light to control neurons. They introduced new light-sensing proteins called Opto-mGluR6 into the eye. In essence, this turned the old cells into photoreceptors. These cells were then able to process incoming light. Even when cells degrade, Opto-mGluR6 survives in the retina. Utilizing existing signaling pathways, they activated the brain’s visual cortex to make sense of visual stimuli.

They tested the treatment by challenging a blind mouse to swim and find a platform that was slightly under the water. Each mouse took a random pathway until they eventually bumped into the platform. After treatment, however, the mice swam directly to the platform, clearly showing they could see the submerged platform.

The researchers are optimistic that they could get the same results in human trials. If this technique works out, millions of patients with progressive degenerative retinal disease could enjoy better eyesight.

Left: Blind mouse has difficulty swimming to the platform. Right: After treatment, swims directly for the platform.

Source: Restoring the ON Switch in Blind Retinas: Opto-mGluR6, a Next-Generation, Cell-Tailored Optogenetic Tool, van Wyk et. al. PLOS Published: May 7, 2015  DOI: 10.1371/journal.pbio.1002143