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?”

“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.  

Retinitis pigmentosa is one of the two leading causes of vision loss in the United States, Western Europe, and Japan, along with another impairment of the rods and cones: age-related macular degeneration. RP can lead to tunnel vision, impaired night vision, and often total blindness. Any effective treatment, bionic or otherwise, would be a major development. 

 “These are diseases where the sensors in the eye, the rods and cones, have deteriorated but the rest of the wiring is still in place,” says Ignatiev. The artificial retina is designed to electrically stimulate the other structures—the bipolar cells, Mueller Cells, and the retinal neurons that play a key role in communicating with the optic nerve to produce sight—that remain essentially intact.

The artificial detectors are so small that they must be attached to a polymer film a few millimeters in size, which is then surgically implanted into the eye. Two weeks later, the polymer film dissolves, leaving the array behind. “We have been using nanotechnology since its inception,” says Ignatiev, referring to materials science focused on the manipulation and control of matter at a scale of 1 to 100 nanometers, otherwise known as 1 billionth of a meter. “We are currently making the ceramic detectors about 10 times larger, at about 40 micrometers, but that’s because you can easily see them with a microscope.”

The discovery of one of the key components of the artificial retina was something of an accident. Ignatiev had been working on a night vision project for NASA when he came upon the ceramic material—a member of a unique class of materials called uncooled infrared detectors—he now uses in the artificial retina.

“We found that this ceramic material was not only sensitive to heat but also to light,” he says. The idea came to him that it might be useful to people with vision problems. Being able to manipulate it at a submicroscopic level was essential; fortunately, it retained its properties at the nanoscale. 

E. Brady Trexler, an Assistant Professor in the Department of Opthamology and Neuroscience at Mount Sinai School of Medicine, says Ignatiev’s ability to create an array of nanoscale photodetectors mimicking the array of cone photoreceptors in size and function places the technology on firm footing as a viable therapy for restoring vision. “The beauty of the design lies in its simplicity,” he says. “In retinal degeneration, photoreceptors are the first to go, and more complex neurons remain, at least for a while. Our hope is that ceramic photodetectors will stimulate the surviving neurons to induce vision.”   

Although the technology’s development has roots in space exploration, it also derives from expertise developed in the semiconductor industry. Virtual Vision uses that expertise to make the arrays like chips in a computer factory. The nanodetectors are stacked in a hexagonal structure in an array mimicking the arrangement of the human rods and cones they are designed to replace. But molecular beam epitaxy was in fact perfected during NASA experiments conducted in 1996 on the Wake Shield Facility, a 12-foot-diameter, disk-shaped platform designed by the Center for Advanced Materials to study epitaxal thin-film growth in the ultra vacuum of space. It was launched from the space shuttle Columbia during the STS-80 mission.   

“We grew thin oxide films using atomic oxygen in low earth orbit as a natural oxidizing agent,” says Ignatiev. “Those experiments helped us develop the oxide ceramic detectors we’re now using.”

Ignatiev’s artificial retina has overcome many of the challenges faced by earlier attempts. The natural layout of the individual detectors solves another problem that plagued earlier silicon-based research: blockage of nutrient flow to the eye. “All of the nutrients feeding the eye flow from the back to the front,” says Ignatiev. “If you implant a silicon detector into the eye, nutrients can’t flow through it, and the neural cells of the eye will atrophy.” 

Scientists at John Hopkins University, MIT, and elsewhere have tried to build artificial rods and cones before, he notes. Most of these earlier efforts involved either electrode implantation into the interior of the eye or silicon-based solar cell implantation into the eye. Silicon, like any foreign substance, can be toxic to the human body and reacts unfavorably with fluids in the eye—problems the ceramic detectors do not share. 

But even space-age research is still subject to the whims of Mother Nature. Garcia, the ophthalmologist treating Boyd, was humbly reminded of such limits during his early animal experiments. Initially, he implanted ceramic detectors in 10 rabbits at the University of Texas Medical School to test for bio-compatibility. The rabbits, however, drowned along with thousands of other research animals when tropical storm Allison hit in 2001, dropping over 35 inches of rainfall on Houston in two days. Throughout the Texas Medical Center, where the medical school is located, thousands of laboratory animals were lost along with decades of research and for many scientists, their life’s work. 

Virtual Vision is now ready to implant the nano device in retinally blind patients, an experiment Garcia expects to begin within the next few years. He plans to conduct this work in Mexico, where the cost of clinical trials is lower than in the United States, and where he has done many other research projects.

Toxicity due to low levels of lead can be subtle, and may not have shown up in their studies, he adds. In addition, the function of the device may be impaired by the formation of scar tissue around it. The next step, Foster says, should be further testing in primates. 

But Ignatiev says his team has already complied with federal regulations. “The rabbits were implanted with the artificial retinas and wore them for 24 months without any toxic effects or any other negative response,” he says. “This is the standard requirement of the Food and Drug Administration.”

After eight years of work on the artificial retina and two patents for the technology, Ignatiev and Garcia would like to proceed. “Our detectors are doing from a physics perspective what they should do,” says Ignatiev. “Is it good enough so that when in the eye they will send a signal to the brain? We don’t know. That’s what we need to find out.” 

But as Garcia admits, “This is a Model T Ford. We hope a person could see the edge of shapes and perhaps get some limited improvement in their field of vision. It will certainly not produce the kind of vision needed for reading.”