WASHINGTON – Scientists are testing artificial retinas that they hope can restore partial sight to people who've lost their vision to the most common causes of blindness.
Retinitis pigmentosa, which ruins peripheral vision, and macular degeneration, which causes a blurred or blind spot in central vision, affect millions of people, especially the elderly.
Both diseases irreparably damage the retina, the light-sensitive patch at the back of the eye that converts images into signals and relays them to the brain.
The government-sponsored researchers' goal is to create sensitive devices that can be implanted in the eye and will let previously blind people recognize faces and read large print.
"Retinal prostheses represent the best near-term hope for individuals with incurable, blinding diseases of the outer retina," said Dr. Mark Humayun, a surgeon at the Doheny Eye Institute at the University of Southern California who has implanted artificial retinas in patients.
Tests of a relatively crude artificial retina began on six patients in 2002.
With the aid of these devices, people who'd been totally blind were able to read foot-high letters, tell a plate from a cup, find doors and windows, and navigate around large objects, according to Brian Mech, vice president of Second Sight Medical Products.
The Sylmar company produced the devices for the U.S. Energy Department's Artificial Retina Project.
The department has been engaged in biological research since the atomic bomb tests of the 1950s raised fears of radiation poisoning.
Call Robert S. Boyd, McClatchy Washington Bureau, (202) 383-6007.
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