Retinal Implants

Abstract

Retinal implants have been designed and fabricated to restore vision in blind RP patients. These implants work by activating neural retinal cells not affected by the degenerative process with an electrode array placed onto (epiretinal approach) or underneath (subretinal approach) the retina. Surgical procedures have been developed for both types of visual prosthesis. Animal experiments have shown that local activation of the visual cortex can be achieved with stimulation currents and charge transfers which are in a biocompatible range. Initial clinical trials in blind human subjects have shown that visual percepts can be achieved. It is hoped that with this technical approach ambulatory vision can be restored in otherwise not treatable degenerative diseases of the retina.