Traveling for Care?
March 7, 2013
The Argus II retinal prosthesis, a device that can restore some vision to people who are almost totally blind, received U.S. market approval from the Food and Drug Administration (FDA) on February 14, 2013. The device was approved for use in adults, age 25 years or older, with severe to profound retinitis pigmentosa who can barely perceive light - or no vision at all - in both eyes, with evidence of intact inner layer retina function and a previous history of the ability to see forms.
The device, which includes a small video camera, transmitter mounted on a pair of eyeglasses, video processing unit (VPU), and an implanted retinal prosthesis, replaces the function of degenerated cells in the retina and may improve a patient’s ability to perceive images and movement. The VPU transforms images from the video camera into electronic data that is wirelessly transmitted to the retinal prosthesis.
The development of the device started at Duke University, under Drs. Eugene de Juan and Mark Humayun, who carried out the first short-term experiments with human volunteers, and was continued with Dr. Robert J. Greenberg and Dr. Gislin Dagnelie in the early 1990s at the Wilmer Eye Institute. The results demonstrated that electrical stimulation of the retina could, indeed, produce spots of light perceived by blind patients. Some recent human subjects research to support the FDA approval was undertaken by Wilmer retina division faculty member Dr. James Handa, the Robert B. Welch Professor of Ophthalmology.
Hendrik P.N. Scholl, M.D., the inaugural Dr. Frieda Derdeyn Bambas Professor of Ophthalmology and Wilmer’s specialist for inherited retinal diseases such as retinitis pigmentosa, is excited about this milestone to restore some useful vision in severely affected patients. "In the clinical trial that led to the approval, most participants were able to perform basic activities better with the Argus II system than without it," he says and adds, "Patients performed significantly better when touching a square on a white field; detecting the direction of a motion; recognizing large letters, words or sentences; detecting street curbs; or walking on a sidewalk without stepping off."
Dr. Fernando Arevalo, adjunct professor of ophthalmology at Wilmer and chief of the vitreoretinal division at King Khaled Eye Specialist Hospital (KKESH), Wilmer's affiliate hospital in Riyadh, Saudi Arabia, already has implanted the Argus II device successfully in a procedure at KKESH last month.