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Am J Ophthalmol. 2007 May;143(5):820-827. Epub 2007 Mar 23.

Visual performance using a retinal prosthesis in three subjects with retinitis pigmentosa.

Author information

1
Doheny Retina Institute at the Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.

Abstract

PURPOSE:

To assess visual task performance in three blind subjects implanted with epiretinal prostheses.

DESIGN:

Prospective, investigational device exemption trial.

METHODS:

Three subjects with light perception or no light perception vision were enrolled at a single center. All subjects had retinitis pigmentosa (RP). Main inclusion criteria: light perception or worse vision in one eye and some visual experience as an adult before blindness. Main exclusion criteria included other ophthalmic problems. A prototype retinal prosthesis was implanted in the eye with worse light sensitivity. The prosthesis had 4 x 4 array of platinum electrodes tacked to the epiretinal surface. The prosthesis was wirelessly controlled by a computer or by a head-worn video camera. Visual function testing was performed in single masked or double masked fashion. Scores from the visual task were compared to chance to determine statistical significance.

RESULTS:

The subjects performed significantly better than chance in 83% of the tests. Using the video camera, subjects scored as follows on simple visual tasks: locate and count objects (77% to 100%), differentiate three objects (63% to 73%), determine the orientation of a capital L (50% to 77%), and differentiate four directions of a moving object (40% to 90%). A subset of tests compared camera settings using multipixels vs single pixels. Using multipixel settings, subjects performed better (17%) or equivalent (83%) in accuracy and better (25%) or equivalent (75%) in reaction time.

CONCLUSIONS:

Three RP implant subjects used epiretinal prostheses to perform simple visual tasks. Multipixel settings proved slightly more effective than single pixel settings.

PMID:
17362868
DOI:
10.1016/j.ajo.2007.01.027
[Indexed for MEDLINE]

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