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“Our hope is that the thin-film ceramic sensors will serve as substitutes for the damaged rods and cones in the eye stimulating the brain to see in much the same way the cochlear implant stimulates the brain to hear.”
No one would ever confuse William Boyd with Steve Austin, the iconic—and bionic—hero of the ‘70s TV series The Six Million Dollar Man. Austin was a top astronaut for NASA whose crash-related injuries led to substantial reengineering of various body parts by way of high-tech implants. Boyd spent his career at the considerably less glamorous Nabisco Bakery in Houston, Texas, mixing the dough that yields Ritz Crackers. In order to regain his fading vision, however, Boyd now hopes to become something of a bionic man himself, or at least a man with a bionic eye.
In 1979, the then 36-year-old father of four began to notice that his eyesight, including his peripheral vision, was changing. He would transfer large tubs of dough onto floor jacks for a trip to the elevator, and then bump into things. It got so bad that his supervisor asked if he’d been drinking.
Boyd eventually went to the doctor, and the diagnosis was devastating: retinitis pigmentosa, or RP, a genetic condition that causes degeneration of the natural photoreceptors—the rods and cones—that line the retina in the back of the eye. The next year, Boyd was forced to retire, his vision so compromised that, to get around, he was forced to rely on a cane and on the help of his daughters.
Now, nearly three decades later, Boyd finally has some hope for improvement. And it rests with his ophthalmologist, Dr. Charles Garcia, and his entrepreneurial efforts to develop an artificial retina which could be implanted in patients. The basic science underlying the device was developed thanks to research sponsored by the ultimate source of Steve Austin’s fictional transformation—the U.S. space program. “Eventually I’ll be completely blind,” says Boyd, now 65. “What do I have to lose?”
To develop the device, Garcia, who is on the faculty at the University of Texas Medical School at Houston, set up a company called Virtual Vision in 2003. Privately owned and angel funded, Virtual Vision is one of several companies that have spun out of research at the University of Houston’s Center for Advanced Materials, one of 11 previously NASA-sponsored Research Partnership Centers. The artificial retina, Virtual Vision’s only product in development, is a thin film consisting of 100,000 ceramic detectors, each of which is five microns in diameter—the same size as the natural photoreceptor rods and cones in the human eye.
These detectors essentially perform the work that the diseased eye’s faulty rods and cones are no longer capable of doing. When working properly, the natural structures convert light to electrical impulses that then travel along 1.2 million neurons in the optic nerve to the brain, where they are processed into coherent images. The natural rods, cylindrical in shape, can detect a single photon, which means they are 100 times more sensitive to light than the cones. Accordingly, the rods allow for vision in low light, but they respond more slowly than cones. Cones require more light, but they provide finer detail and a faster response time that allows clear perception of rapidly changing images. Cones are also sensitive to color.
“Our hope is that the thin-film ceramic sensors will serve as substitutes for the damaged rods and cones in the eye stimulating the brain to see in much the same way the cochlear implant stimulates the brain to hear,” says Virtual Vision Vice President Alex Ignatiev, who is also the director of the Center for Advanced Materials at the University of Houston.
