In healthy eyes, light is first converted to electrical signals via the rods and cones (photoreceptors) and transmitted through RGCs to the vision perceiving part brain. In many inherited retinal diseases including Retinitis Pigmentosa, Choroideremia, and Stargardt Disease, rods and cones degenerate, affecting an individual’s ability to perceive light. While photoreceptors degenerate, as RGCs are preserved. As such, they represent a target cell to bypass the degenerated photoreceptors to perceive light and signal the brain.
Specifically, inside RGCs, molecular photoswitches change shape depending on the presence or absence of light. In the absence of light, they are in the “off” position. In the presence of light, they change shape, turning to an “on” position that triggers the RGC to signal the brain.