The semiconductor-based microphotodiode array artificial silicon retina

Two general prosthetic approaches have been developed, each centered around permanent ocular implantation. We have been exploring an alternative approach centered around the implantation of a semiconductor-based microphotodiode array disk into the subretinal space. The basic concept of the 'subretinal' approach is that this device may be used to artificially alter the membrane potential of neurons in the outer retina or remnants of this structure. In theory, the location of this prosthetic input has the advantage of allowing the normal processing networks of the retina to transmit this signal centrally. We review the status of this project, focusing on recent studies in cat, which possesses an eye with many similarities to human, not the least of which is a dual retinal and choroidal circulation.