Current and future prospects for optoelectronic retinal prostheses.

There has been accelerating progress in the development of retinal prosthesis systems designed to partially restore vision to people with retinitis pigmentosa or macular degeneration. Current retinal prostheses can be divided into two types: those that receive power and information from passive or active photodiodes (optoelectronic systems) and those based on multielectrode arrays powered by cables or transcutaneous telemetry systems. Currently, four research groups have ongoing chronic implantation clinical studies, and two of these groups plan to have commercial retinal prosthesis systems available within the next 2 years. This paper reviews the development and current status of the most significant international retinal prosthesis research groups and discusses future prospects and issues associated with their retinal prosthesis systems.