title: Predicting visual sensitivity in retinal prosthesis patients.
abstract: 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.).
authors.affiliation: Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA. horsager@usc.edu
authors.forename: Alan
authors.initials: A
authors.lastname: Horsager
authors.forename: Scott H
authors.initials: SH
authors.lastname: Greenwald
authors.forename: James D
authors.initials: JD
authors.lastname: Weiland
authors.forename: Mark S
authors.initials: MS
authors.lastname: Humayun
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Greenberg
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: McMahon
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Boynton
authors.forename: Ione
authors.initials: I
authors.lastname: Fine
mesh_terms: 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*