Abstract
Purpose: :
To test if patients blinded by outer retinal dystrophies can consistently perceive different colors with the Argus II Retinal Prosthesis System.
Methods: :
Nine blind subjects with retinitis pigmentosa (bare light perception or worse vision in both eyes, functional ganglion cells and intact optic nerve, confirmed history of useful form vision), fitted with the Argus II retinal prosthesis were tested. Different groups of electrodes were stimulated with trains of cathodic-anodic pulses with different parameters. Subjects reported the color they perceived after each stimulation.
Results: :
Eight different colors were perceived by the subjects (orange, yellow, red, blue, green, pink, gray and white). The orange and pink colors were perceived by three subjects, the blue color was perceived by four subjects, the yellow and white colors were perceived by six subjects, the green and red colors were perceived by two subjects and the gray color was perceived by one subject. All the stimulations were repeated twice and all the color perceptions obtained were repeatable. Different colors can be stimulated from the same part of the prosthesis but with different parameters.
Conclusions: :
Blind patients fitted with the Argus II Retinal Prosthesis System were able to consistently perceive different colors with electrical stimulation. This is the first time that a retinal prosthetic device has been shown to allow a group of blind patients to perceive color. These data, as well as data from future studies, could allow us to provide a rudimentary version of color vision to blind patients.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00407602
Keywords: retinitis • color vision • clinical (human) or epidemiologic studies: systems/equipment/techniques