About 50 Americans and Europeans have been using it in clinical trials for several years, including six patients who underwent testing at the University of Pennsylvania's Scheie Eye Institute, followed by surgery at Wills Eye Institute.
The system includes a small video camera and transmitter mounted on a pair of glasses. Images from the camera are processed into electronic data that are wirelessly transmitted to electrodes implanted in the patient's retina.
Julia A. Haller, Wills' ophthalmologist-in-chief, recalled the powerful testimonials from patients in September to the FDA. "I've been a retina specialist for almost 30 years, and I can't remember a more moving experience," Haller said. "A lawyer from Chicago talked about his son coming up to him and for the first time, he could see his face."
The FDA says that while the device will not fully restore patients' vision, "it may allow them to detect light and dark," helping them with daily tasks.
And that can improve quality of life. In 2009, Michael Adler, a massage therapist from Mantua, Gloucester County, who has been legally blind since birth, received the artificial retina. Gradually, he became able to distinguish dishes on a table, a hymnal in church, lights on the boardwalk at night. "This is all new to me," he told The Inquirer in 2009.
The FDA approved the device from Second Sight Medical Products for patients 25 and older with advanced retinitis pigmentosa. Starting in their 20s, people with the disease slowly lose vision as the light-sensitive cells that line the retina deteriorate. Over several decades, they become blind.
"It's like looking down a tunnel that gradually narrows until it disappears entirely," said Robert Greenberg, Second Sight's CEO. "What we're doing is reopening the window." Greenberg first proposed the Argus technology as a doctoral student at Johns Hopkins Medical School 20 years ago. He founded Second Sight to develop the technology in 1998.
About 100,000 people in this country have retinitis pigmentosa, though the FDA estimates fewer than 4,000 will initially receive the device under its approved indication. Patients must have little to no light perception in both eyes but a prior history of being able to make out basic shapes and forms. They must also have signs of at least some remaining retinal function.
A study of 30 patients with the condition found that most could perform daily activities better with the implant than without it. Activities included navigating sidewalks and curbs, matching socks, and recognizing large words.
Second Sight hopes to win approval to treat many vision disorders, including macular degeneration, the leading cause of blindness in developed countries.
Inquirer staff writer Marie McCullough contributed to this article.