The Bionic Eye

Serendipity, they say, only happens to good scientists. One day almost 20 years ago, it happened with a wallop to Dr. Joseph F. Rizzo III. A small man with the physical energy of a boxer, Rizzo was hunched over a lab table at Massachusetts General Hospital, wearily transplanting yet another damnably fragile rabbit retina - the diameter of a small coin and as thick as three or four human hairs - from one animal to another. Under his lab coat, Rizzo, now 51, recalls that he was, as usual, wearing a tie. "Scientists don't wear ties," he observes wryly. In the lab, scientists are an informal lot, brainpower being considerably more valued than crisp jeans, ironed shirts, or, God forbid, ties.

But Rizzo, a reserved, formal guy anyway, was no ordinary scientist. He had taken 13 years of training after medical school, eventually becoming, by his own reckoning, one of only five people in the world to be board-certified in ophthalmology and neurology. His entire raison d'etre was to help the blind and vision-impaired see again, especially those who had lost part or all of their vision to macular degeneration, which affects 10 million Americans, or retinitis pigmentosa, which has affected 100,000. He kept his tie on, quite simply, because he never knew when he'd be called back to his office to his real job, seeing these patients.

That day in the lab, Rizzo's patience was wearing thin. He'd been transplanting rabbit retinas for nearly two years, and it was tedious work. Other researchers had already shown that retinal cells could be transplanted from one lab animal to another and that some of the cells would survive. "But nobody had ever transplanted a full-thickness retina before," he says. A full-thickness retina contains not just the rod and cone cells that receive light but a nerve layer that connects the eye to the brain.

Suddenly, he had an epiphany. As he was cutting through a rabbit retina, he realized he was cutting through the very nerve cells that actually remain healthy in people with macular degeneration and retinitis pigmentosa after the light-receiving cells die. Simultaneously, he had a flashback to an article on microelectronics he had read while riding the Red Line from MIT to MGH. "It all came together," he recalls. Perhaps retinal transplants weren't the solution.

He realized that if he could make a device small yet powerful enough to stimulate the still-healthy retinal nerves, it would be nothing less than a bionic eye.

After World War II, scientists began building tiny electronic devices to stimulate nerves in deaf people, and today, cochlear implants are a medical success story. But a bionic ear was child's play compared with a bionic eye while each ear has 30,000 nerve fibers, each eye has 1 million nerve fibers that connect the retina to the brain.

The initial strategy that Rizzo and some other researchers are pursuing is to hook a tiny video camera to a pair of eyeglasses. (It would work only in patients who once had enough vision to allow development of the visual part of the brain.) A silicon chip on the camera sends a digitized image to another chip implanted near the retina. This second chip transmits signals to electrodes. The electrodes stimulate the nerve cells to the brain, thus bypassing damaged parts of the retina. Ultimately, Rizzo says, the hope is to get rid of the camera and put its chip underneath the retina.

Though it only takes a dozen or so electrodes to restore the ability to see light and dark and shapes, it will take hundreds, maybe thousands, to restore the ability to read and recognize faces. But if anyone can do it, it may well be Rizzo, who works with John L. Wyatt Jr., a professor of electrical engineering at MIT. Sixteen years ago, Rizzo and Wyatt created the Boston Retinal Implant Project, a collaboration that now includes the Massachusetts Eye and Ear Infirmary, Harvard Medical School, MIT, the Cornell Nanofabrication Laboratory, the Center for Innovative Visual Rehabilitation at the Boston Veterans Administration hospital, which Rizzo directs, and others.

In his office at Mass. Eye and Ear, filled with pictures of his daughter, Rizzo details his path from a Jesuit school in New Orleans to college and medical school at Louisiana State University. Rizzo discovered early on that "learning science was fun." In high school, he played clarinet until he started playing basketball, becoming, at 5 feet 4 inches, "the shortest person in the New Orleans league." And he fell in with a cohort of boys who, he says, "egged each other on and helped form each other's career goals." They traveled as a pack to college and medical school. When his father died this fall, the gang, all of them now doctors, came to the wake.

In his work, too, Rizzo has found support. After his epiphany, he approached his mentor, MGH neurophysiologist Richard Masland. "He looked at me and said, `Joe, I think it's a good idea. But if you do this, do not do anything else,'" Rizzo recalls. "It would have been easy to drift. . . . But I have committed myself to this."

So have others. A pair of scientists, Mark Humayun and Eugene de Juan, came up with their own idea for a bionic eye, which they are pursuing at the Doheny Eye Institute of the University of Southern California. A team at the Optobionics Corp. in Naperville, Illinois, has joined the race to make a bionic eye, as have teams from Germany and Japan. So far, Rizzo and Wyatt's group has implanted temporary prototypes in six patients. One, David Robinson, 32, an Internet worker in Salt Lake City, describes seeing "small shapes and half moons" on a computer during the experiment. But the Rizzo-Wyatt team has held off finding a corporate partner. "The longer we can put off declaring a particular design, the better."

The Humayun group has implanted devices in six patients and works with Second Sight Medical Products Inc. in Sylmar, California. One Humayun patient, Connie Schoeman, 77, of La Canada Flintridge, California, can differentiate between a plate and a knife.

At Optobionics, Dr. Alan Chow has developed a device, now implanted in 10 patients, that has just one tiny silicon chip, made of thousands of miniature solar cells, placed under the retina. Other scientists doubt it is powerful enough to stimulate retinal cells. But one of Chow's patients, Maria Zaccaro, 43, says she can "walk around in stores on my own and pick things out."

Rizzo and Wyatt believe their implant will be better tolerated than anyone's. It is, Wyatt notes, "enormously less invasive." (The device is a chickpea-sized copper coil that is tucked under the bony part of the eyebrow, where it receives radio signals from the video camera and sends them to an adjacent chip. The only part of the device that goes inside the eye is a tiny strip of electrodes placed just under the membrane surrounding the eyeball, underneath the retina.)

Michael Young, director of Boston's Minda de Gunzburg Research Center for Retinal Transplantation at Schepens Eye Research Institute, believes that the best path to vision restoration is stem cell transplantation, not a retinal implant. Still, he says that of those trying to make a bionic eye, Rizzo and Wyatt "are on the right track." Rizzo himself is cautious. In the next decade, he says, "it is reasonably likely that someone who has been blind will be able to walk safely in an unfamiliar environment. The next goal after that . . . is to allow formerly blind people to recognize faces, to see if someone is smiling or frowning, and to pick up other emotional cues that are so important for normal social contact. If we are successful in these first two goals, then the next challenge, and it's a much harder one, is to help formerly blind people read."

Judy Foreman's syndicated health column appears every other week in the Globe and other newspapers. Reach her at foreman@globe.com.