Retinal prosthesis for the blind.
Most of current concepts for a visual prosthesis are based on neuronal electrical stimulation at different locations along the visual pathways within the central nervous system. The different designs of visual prostheses are named according to their locations (i.e., cortical, optic nerve, subretinal, and epiretinal). Visual loss caused by outer retinal degeneration in diseases such as retinitis pigmentosa or age-related macular degeneration can be reversed by electrical stimulation of the retina or the optic nerve (retinal or optic nerve prostheses, respectively). On the other hand, visual loss caused by inner or whole thickness retinal diseases, eye loss, optic nerve diseases (tumors, ischemia, inflammatory processes etc.), or diseases of the central nervous system (not including diseases of the primary and secondary visual cortices) can be reversed by a cortical visual prosthesis. The intent of this article is to provide an overview of current and future concepts of retinal and optic nerve prostheses. This article will begin with general considerations that are related to all or most of visual prostheses and then concentrate on the retinal and optic nerve designs. The authors believe that the field has grown beyond the scope of a single article so cortical prostheses will be described only because of their direct effect on the concept and technical development of the other prostheses, and this will be done in a more general and historic perspective.
Margalit
Eyal
E
Intraocular Prosthesis Group, Wilmer Eye Institute, Johns Hopkins, Baltimore, MD 21287-9277, USA.
Maia
Mauricio
M
Weiland
James D
JD
Greenberg
Robert J
RJ
Fujii
Gildo Y
GY
Torres
Gustavo
G
Piyathaisere
Duke V
DV
O'Hearn
Thomas M
TM
Liu
Wentai
W
Lazzi
Gianluca
G
Dagnelie
Gislin
G
Scribner
Dean A
DA
de Juan
Eugene
E
Humayun
Mark S
MS
D001766:Blindness / Q000628:therapy*; D004558:Electric Stimulation / Q000295:instrumentation*; D006801:Humans; D020007:Implants, Experimental; D009901:Optic Nerve Diseases / Q000628:therapy*; D010775:Photic Stimulation / Q000295:instrumentation*; D011474:Prosthesis Design; D012164:Retinal Diseases / Q000628:therapy*; D012449:Safety