Optogenetic vision restoration

A gene-therapy alternative to electrode arrays: an opsin (e.g. the red-shifted ChrimsonR) is delivered by AAV to surviving inner-retinal neurons, typically ganglion or bipolar cells, conferring light sensitivity on cells that are not normally photoreceptors. Light-amplifying, image-projecting goggles supply the high, wavelength-tuned intensities the opsins need and encode the scene.

A first-in-human trial reported partial functional recovery, in which a blind retinitis-pigmentosa participant could locate, count, and touch objects with the goggles, establishing proof of principle while making clear that the vision is coarse and slow. Advantages over electrodes include potential cellular resolution and no implanted array; open challenges are opsin light-sensitivity and kinetics, restriction to surviving cells, immune response, and durable expression.