Electronic approaches to restoration of sight

• Published in: Reports on progress in physics Vol. 79; no. 9; p. 096701
• Main Authors: Goetz, G A, Palanker, D V
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 01.09.2016
• Subjects: brain-machine interface; electrical stimulation; neural prosthesis; neural stimulation; phosphene; retina; retinal prosthesis
• ISSN: 0034-4885; 1361-6633
• DOI: 10.1088/0034-4885/79/9/096701

Retinal prostheses are a promising means for restoring sight to patients blinded by the gradual atrophy of photoreceptors due to retinal degeneration. They are designed to reintroduce information into the visual system by electrically stimulating surviving neurons in the retina. This review outlines the concepts and technologies behind two major approaches to retinal prosthetics: epiretinal and subretinal. We describe how the visual system responds to electrical stimulation. We highlight major differences between direct encoding of the retinal output with epiretinal stimulation, and network-mediated response with subretinal stimulation. We summarize results of pre-clinical evaluation of prosthetic visual functions in- and ex vivo, as well as the outcomes of current clinical trials of various retinal implants. We also briefly review alternative, non-electronic, approaches to restoration of sight to the blind, and conclude by suggesting some perspectives for future advancement in the field.