Predicting visual sensitivity in retinal prosthesis patients.
OBJECTIVE
With the long-term goal of restoring functional vision in patients with retinal degenerative diseases, the eyes of blind human subjects were implanted chronically with epiretinal prostheses consisting of two-dimensional electrode arrays that directly stimulated cells of the neural retina.


METHODS
Psychophysical techniques were used to measure the brightness of electrically generated percepts on single electrodes using a variety of electrical stimulation patterns.


RESULTS
It was possible to predict the sensitivity of the human visual system to a wide variety of retinal electrical stimulation patterns using a simple and biologically plausible model.


CONCLUSIONS
This is the first study to demonstrate that, on the single-electrode level, retinal electrical stimulation in humans can produce visual qualia that are predictable using a quantitative model, a prerequisite for a successful retinal prosthesis. (ClinicalTrials.gov number, NCT00279500.).
Horsager
Alan
A
Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA. horsager@usc.edu
Greenwald
Scott H
SH
Weiland
James D
JD
Humayun
Mark S
MS
Greenberg
Robert J
RJ
McMahon
Matthew J
MJ
Boynton
Geoffrey M
GM
Fine
Ione
I
D001766:Blindness / Q000503:physiopathology* / Q000601:surgery; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D006801:Humans; D008839:Microelectrodes; D008875:Middle Aged; D008954:Models, Biological; D010775:Photic Stimulation; D019919:Prosthesis Implantation; D012160:Retina / Q000502:physiology*; D012162:Retinal Degeneration / Q000503:physiopathology* / Q000601:surgery; D012684:Sensory Thresholds / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*