gms | German Medical Science

In the US, in Japan, and in Germany several projects were conducted to develop implantable visual prostheses with considerable participation of public and private investors. The most advanced projects are based on retinal stimulators mounted onto or underneath the retina to elicit visual perception by functional electric stimulation in patients with progressive retinal dystrophies, e.g. in Retinitis pigmentosa. Further developments in engineering, e.g. the complete telemetric control of epiretinal stimulators or active energy transfer systems for subretinal devices were achieved. Studies were conducted in humans suffering from retinal degenerations to evaluate safety and biocompatibility in acute and chronic human trials and also to collect information on the efficacy of the prototype systems to improve them. In these experiments it became evident that blind subjects may have visual percepts with which they are able to identify large high contrast objects. It became further evident that the prototypes developed so far are safe for the patients. In the next three years further systems will be tested and evaluated in pilot trials before larger clinical trials will be conducted to make these devices available for a larger group of patients.