title: Photovoltaic Retinal Prosthesis with High Pixel Density.
abstract: Retinal degenerative diseases lead to blindness due to loss of the "image capturing" photoreceptors, while neurons in the "image processing" inner retinal layers are relatively well preserved. Electronic retinal prostheses seek to restore sight by electrically stimulating surviving neurons. Most implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems, which deliver energy to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which silicon photodiodes in each pixel receive power and data directly through pulsed near-infrared illumination and electrically stimulate neurons. Stimulation was produced in normal and degenerate rat retinas, with pulse durations from 0.5 to 4 ms, and threshold peak irradiances from 0.2 to 10 mW/mm(2), two orders of magnitude below the ocular safety limit. Neural responses were elicited by illuminating a single 70 μm bipolar pixel, demonstrating the possibility of a fully-integrated photovoltaic retinal prosthesis with high pixel density.
authors.affiliation: Hansen Experimental Physics Laboratory, Stanford University ; Santa Cruz Institute for Particle Physics, UC Santa Cruz.
authors.forename: Keith
authors.initials: K
authors.lastname: Mathieson
authors.forename: James
authors.initials: J
authors.lastname: Loudin
authors.forename: Georges
authors.initials: G
authors.lastname: Goetz
authors.forename: Philip
authors.initials: P
authors.lastname: Huie
authors.forename: Lele
authors.initials: L
authors.lastname: Wang
authors.forename: Theodore I
authors.initials: TI
authors.lastname: Kamins
authors.forename: Ludwig
authors.initials: L
authors.lastname: Galambos
authors.forename: Richard
authors.initials: R
authors.lastname: Smith
authors.forename: James S
authors.initials: JS
authors.lastname: Harris
authors.forename: Alexander
authors.initials: A
authors.lastname: Sher
authors.forename: Daniel
authors.initials: D
authors.lastname: Palanker