Age-related macular degeneration is the leading cause of blindness in North America, while retinitis pigmentosa causes approximately 1.5 million people worldwide
Photovoltaic retinal prosthesis with high pixel density
Keith Mathieson, James Loudin, Georges Goetz, Philip Huie, Lele Wang, Theodore I. Kamins, Ludwig Galambos, Richard Smith, James S. Harris, Alexander Sher & Daniel Palanker
AffiliationsContributionsCorresponding author
Nature Photonics (2012)
Published online 13 May 2012
“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 the surviving neurons. Most implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems that 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 is produced in normal and degenerate rat retinas, with pulse durations of 0.5–4 ms, and threshold peak irradiances of 0.2–10 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.”
