Retinal prosthesis study recruitment partially completed

Journal of Visual Impairment & Blindness, March, 2008

The University of Southern California and Second Sight Medical Products, a developer of retinal prostheses for treating blindness, recently announced that they have completed enrollment of the first phase of a three-year clinical Investigational Device Exemption trial of the Argus II Retinal Prosthesis System in the United States; enrollment for the study in Europe and Mexico continues. The Argus II is the second generation of an electronic retinal implant designed for the treatment of retinitis pigmentosa, an inherited eye disease that affects the retina and causes visual impairment. The Argus II implant consists of an array of 60 electrodes that are attached to the retina. These electrodes conduct information acquired from an external camera to the retina to provide a rudimentary form of sight to implanted subjects. The development of this technology was supported by the NEI and the U.S. Department of Energy's Office of Science Artificial Retina Project, which is helping to advance the implant's design and construction.

Ten subjects in the United States have been recruited for the Phase I Argus II trial. Robert Greenberg, president and chief executive officer of Second Sight, who has worked in the field of retinal prostheses for more than 15 years, said,

   Although it is too early to comment on the
   clinical data, each device continues to
   function as expected, and all participants
   are using their systems at home daily.

The U.S. trials are currently being conducted at four ophthalmic centers throughout the country, including Doheny Eye Institute at the University of Southern California, Wilmer Eye Institute at Johns Hopkins University in Maryland, the University of California at San Francisco, and the Retina Foundation of the Southwest in Texas. Second Sight will be seeking expansion of the U.S. trial to include additional sites, including at Columbia University Medical Center and Lighthouse International in New York, Scheie Eye Institute and Wills Eye Hospital in Pennsylvania, and Emory University and the Atlanta VA Rehabilitation Research and Development Center in Georgia. Internationally, the Argus II study began in Mexico in the fall of 2006, as well as at two sites in Switzerland and France. A third study site at Moorfields Eye Hospital in London, England, has recently received approval from the U.K. government and is expected to begin enrollment shortly.

Mark Humayun, who is conducting this study in the United States, was the first physician to perform an Argus II implantation procedure in the United States. He is a professor of ophthalmology, biomedical engineering, and cellular and neurobiology at the Doheny Eye Institute, Keck School of Medicine, University of Southern California. Dr. Humayun implanted the first generation 16electrode prosthesis (Argus 16), in six subjects with retinitis pigmentosa between 2002 and 2004. His work demonstrated the ability of participants to detect when lights were on or off, count and describe the motion of objects, and locate and differentiate simple objects in an environment. More information on the trial can be found online at: . For more information, contact: Doheny Eye Institute, 1450 San Pueblo Street, Los Angeles, CA 90033; phone: 323-442-6313; web site: <www.doheny.com>.