Monday, March 9, 2009

New device restores some vision in blind people

From the San Francisco Chronicle:

In a darkened room, Dean Lloyd (pictured) sits before a computer screen slowly moving his head, searching for a white box on the black screen.

Then he points directly at the square.

Lloyd has been blind for two decades.

About 18 months ago, the 68-year-old attorney in Palo Alto had an experimental electrode implanted at the back of his right eye, part of a complex electrical system designed to give him rudimentary vision.

He's among only 18 blind people in the world - 10 in the United States - to undergo the procedure.

Lloyd wears an apparatus that could be out of a sci-fi novel - black sunglasses containing a tiny camera and transmitter, video processor and battery pack on his belt, electrode-studded array tacked to the back of his eye.

The mechanism represents new hope for blind people, particularly those with retinitis pigmentosa, a devastating hereditary disease that destroys vision.

"It's not perfect, but it's incredibly exciting," said Dr. Timothy Schoen, director of preclinicial research at the nonprofit Foundation Fighting Blindness, which funds research. "Some people with the device can see large objects, they can see dark from light,"

Called Argus II, the device is part of a panoply of revolutionary research around the country that seeks to restore vision to more than 10 million people who have lost it due to macular degeneration, retinitis pigmentosa, Usher syndrome and other diseases. The research includes gene therapies, dietary treatments, even the development of artificial retinas.

"Patients with extreme vision loss have a greater cause for optimism than they have in the past," said retinal specialist Dr. Jacque Duncan, a UCSF associate professor of clinical ophthalmology who is involved in the Argus II clinical trial. Lasting 36 months, the trial will determine the safety of the prosthetic device and is about halfway complete.

With the mechanism, wearers see crude shapes or forms, such as the outlines of a person. Many see doorways. Many perceive fuzzy spots of light, others say images look like fireworks.

Argus II bypasses sensory cells that have died and takes messages to the brain, sending tiny electrical pulses through the vision pathway to the retina. It was developed by Second Sight Medical Products Inc., a 10-year-old firm based in Sylmar, in Los Angeles County.

"The device helps people feel more connected to the world," said senior principal scientist Dr. Matthew McMahon. "One subject said she could point to the full moon - for 15 years she hasn't been able to do that, and for her it was a huge deal. A realistic goal is to get to the point where people can see patterns and shapes much more reliably, and ultimately, to be able to read and recognize faces."

Argus II contains 60 electrodes. The next generation might utilize more than a thousand electrodes, said McMahon.

Lloyd can now see primary colors, as well as objects with high water content, such as eyes. He can walk along a white line on a dark floor, or locate an object on a computer screen.

It's a relatively crude form of vision - but it's much more than he's had for many years.

"When I first got it I thought it was pretty useless," he said. "But it's getting a lot better. I can see edges and borders and boundaries. An eye looks like a star to me. I hadn't seen color for a long time. The red I see is a beautiful shade. The blue is luminescent. The green, it's just plain old green.

"I was probably hoping for a lot more than I received, but I'm not disappointed because it is more than I had."

Lloyd was nearly 24, a medical school student, when he was diagnosed with retinitis pigmentosa. The disease, even decades later, has no cure, no effective treatment. It affects about 100,000 people in the United States.

He gave up his hopes of becoming a doctor, and worked as a biochemist and software engineer before becoming a lawyer. For years, his vision was somewhat stable, then it began to fade and finally vanished.

Lloyd has a particularly strong incentive to participate in the trial: his brother, who is also blind, has the disease. And so do several other members of his immediate family, including his daughter, Lisa.

Now 37, and living in Sunnyvale, Lisa Lloyd was diagnosed when she was 22. Director of development at the Northern California chapter of Foundation Fighting Blindness, her vision is relatively fine during the day, but she stopped driving at night five years ago.

"This device is such a big step in the right direction," she said. "My dad went from no light perception to being able to see my hand. Just a few weeks ago, we were walking by a creek. Dad told me the water looked to be about 4 inches high. He was right."