title: Performance of real-world functional vision tasks by blind subjects improves after implantation with the Argus® II retinal prosthesis system.
abstract: BACKGROUND
  The main objective of this study was to test Argus II subjects on three real-world functional vision tasks.
  
  
  METHODS
  The study was designed to be randomized and prospective. Testing was conducted in a hospital/research laboratory setting at the various participating centres.
  
  
  METHODS
  Twenty eight Argus II subjects, all profoundly blind, participated in this study.
  
  
  METHODS
  Subjects were tested on the three real-world functional vision tasks: Sock Sorting, Sidewalk Tracking and Walking Direction Discrimination task MAIN OUTCOME MEASURES: For the Sock Sorting task, percentage correct was computed based on how accurately subjects sorted the piles on a cloth-covered table and on a bare table. In the Sidewalk Tracking task, an 'out of bounds' count was recorded, signifying how often the subject veered away from the test course. During the Walking Direction Discrimination task, subjects were tested on the number of times they correctly identified the direction of testers walking across their field of view.
  
  
  RESULTS
  The mean percentage correct OFF versus ON for the Sock Sorting task was found to be significantly different for both testing conditions (t-test, P < 0.01). On the Sidewalk Tracking task, subjects performed significantly better with the system ON than they did with the system OFF (t-test, P < 0.05). Eighteen (18) of 27 subjects (67%) performed above chance with the system ON, and 6 (22%) did so with system OFF on the Walking Direction Discrimination task.
  
  
  CONCLUSIONS
  Argus II subjects performed better on all three tasks with their systems ON than they did with their systems OFF.
authors: Lions Vision Research and Rehab Center, Johns Hopkins University, Baltimore, Maryland, USA.
authors: Gislin
authors: G
authors: Dagnelie
authors: Second Sight Medical Products Inc, Sylmar, California, USA.
authors: Punita
authors: P
authors: Christopher
authors: Lighthouse Guild, New York, New York, USA.
authors: Aries
authors: A
authors: Arditi
authors: Moorfields Eye Hospital, London, UK.
authors: Lyndon
authors: L
authors: da Cruz
authors: University of California, San Francisco, California, USA.
authors: Jacque L
authors: JL
authors: Duncan
authors: Wills Eye Hospital, Philadelphia, Pennsylvania, USA.
authors: Allen C
authors: AC
authors: Ho
authors: Department of Ophthalmology, University of Southern California, Los Angeles, California, USA.
authors: Lisa C
authors: LC
authors: Olmos de Koo
authors: Quinze-Vingts National Ophthalmology Hospital, Paris, France.
authors: José-Alain
authors: JA
authors: Sahel
authors: Manchester Royal Eye Hospital, Manchester, UK.
authors: Paulo E
authors: PE
authors: Stanga
authors: Geneva University Hospital, Geneva, Switzerland.
authors: Gabriele
authors: G
authors: Thumann
authors: Retina Foundation of the Southwest, Dallas, Texas, USA.
authors: Yizhong
authors: Y
authors: Wang
authors: Second Sight Medical Products Inc, Sylmar, California, USA.
authors: Maura
authors: M
authors: Arsiero
authors: Second Sight Medical Products Inc, Sylmar, California, USA.
authors: Jessy D
authors: JD
authors: Dorn
authors: Second Sight Medical Products Inc, Sylmar, California, USA.
authors: Robert J
authors: RJ
authors: Greenberg
mesh_terms: D001766:Blindness / Q000503:physiopathology / Q000534:rehabilitation*; D004567:Electrodes, Implanted; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D012160:Retina / Q000503:physiopathology*; D014792:Visual Acuity; D057488:Visual Prosthesis; D019987:Persons with Visual Disabilities / Q000534:rehabilitation*; D016138:Walking
keywords: activities of daily living; clinical trial; outcome measures; retinal prosthesis; visual performance