By Peg Brickley
Small Times Correspondent

April 11, 2002 — Optobionics Inc., one of three U.S.-based developers of retinal replacement technology, appears to be gaining ground in the race to produce the first microscopic system to help the blind see.

The Illinois-based private firm picked up $20 million in new funding earlier this year and is readying an article for one of the scientific journals that are the chosen


forum for announcing big scientific news. What that news is, Optobionics will not say.

But the latest round of investment valued the 12-person company at $100 million, according to Alan Chow. A pediatric ophthalmologist, he founded Optobionics with his brother, Vincent, an electrical engineer.

Brian Chee, a partner in the Seattle office of Polaris Venture Partners, said his firm made “a huge bet” on Optobionics, which he said had “an elegant solution combining silicon and biology.”

“In order to get that kind of money, especially in this environment, Optobionics definitely made a strong showing of future promise,” said Scott Maece, an executive at corporate backer Ciba Vision, based outside of Atlanta.

Optobionics has “numerous national and international patents” to back that valuation up, Chow said. The company also has news coming out soon that is likely to impress the scientific community.

In the past two years the company implanted microphotodiode-equipped chips into the back of the eyes of half a dozen blind people in FDA-approved safety tests.

The Optobionics artificial retina is a chip about 2 millimeters in diameter, holding about 3,500 light-sensors that convert light energy to electrical signals, mimicking the eye’s own photoreceptors. When tucked into a pocket behind still-active cells in damaged retinas, the microphotodiodes are supposed to stimulate the live portions of the retina to “see.”

The company, which is working with MEMS specialists, has so far given only limited information on the results of the surgeries, citing FDA rules for early clinical trials.

“There has been no infection, no inflammation, no degradation,” said David McComb, chief information officer at Optobionics. “In effect, the patients are tolerating the devices and the devices are tolerating the patients.”

But the evidence of $20 million in new venture cash, the addition of a new corporate backer, Medtronic Inc., to the roster of investors and the planned journal publication suggest the news out of the first small trial will be pretty good.

A team from Optobionics is slated to talk about the safety, feasibility and efficacy of the company’s artificial silicon retinal prosthesis in less than a month, when the Association for Research in Vision and Ophthalmology holds its annual meeting in Ft. Lauderdale, Fla. Chow and doctors from Tulane University School of Medicine in New Orleans and Rush-Presbyterian St. Luke’s Medical Center in Chicago will tell what the technology has shown in the first small group of test subjects, people blinded by retinitis pigmentosa.

“RP,” as it is known to eye doctors, is one of a number of pathologies that blind by attacking the rods and cones that make up the natural array of light sensors in the human retina.

Optobionics is one of a number of companies concocting technologies to counter those diseases. Besides the Midwestern private venture, there are university-based teams on both the East and West coasts working on systems to transmit images to the brain when diseased retinal tissues are no longer up to the task.

At the University of Southern California’s Doheny Eye Institute, a synthetic retina is headed to clinical trials soon, the product of work that began at the Wilmer Eye Institute at Johns Hopkins Hospital in Baltimore. Most of the Wilmer synthetic retina team left late last year to continue the work at USC. Led by Mark S. Humayun and Eugene de Juan Jr., the team now operates out of the Doheny Retina Institute and works with Second Sight, a Valencia, Calif. firm.

Unlike the Optobionics implant, the Doheny design involves an external camera that sends signals to a receptor array on a chip implanted near the ganglion cells, which send signals to the brain.

The system is similar to one that has been in the works for years at the Harvard-M.I.T. Retinal Implant Project. The East Coast academics are tapping the Cornell Nanofabrication Facility for technical expertise for their design, which aims to put as much of the burden as possible on external cameras, computers and transmitters.

With FDA approval, the Harvard-MIT group has conducted very early stage experiments with human volunteers who, awake on the operating table, answered questions about what they thought they “saw” via a simple system of wireless transmission and microchip.

Douglas B. Shire of the Cornell nanofabrication facility cited the difficulty of getting electronic circuits to operate in the saline environment of the eye as a major hurdle.

“We need to protect the circuitry in the implant from the body environment and vice versa,” Shire said. “We need a biocompatible coating that will withstand the eye environment, which is a salty sort of liquid.”

Biocompatibility is one reason Optobionics puts its chip behind the eye, instead of next to the neurons, where the Harvard-MIT and USC designers plan to place it, Chow explained.

“The placement of the device in the subretinal space protects it somewhat from that attack,” the ophthalmologist said. “It’s a relatively dry environment, as opposed to placement in the vitreous cavity, where essentially it has to operate in sea water.”

Shire, an electrical engineer who cut his teeth on microelectronics in the Silicon Valley, said his team was still testing to find the ideal electrode size.

“The key factor in the design of the implant is minimizing the amount of power that can be used, because there’s a limited budget as far as power is concerned,” Shire said.

“In turn, that limits the size of the stimulating array that conveys information to the patient, because obviously a larger array would consume more power.”

And what is Optobionics’ answer to questions about whether its implanted array has enough power to transmit images using only the light that enters the eye, rather than external cameras, computers and transmitters? Chow would only say that the information is proprietary.

Meanwhile, experiments in size and materials continue in the hunt for the best formulation for the microphotodiodes to do their work of converting photons of light into electricity to signal the brain without corroding. But it appears that the future of synthetic retinas is hooked to the next wave of developments in chip fabrication and nanotechnology.

Tests at the Cornell nanofabrication facility indicate that electrodes with diameters over 300 microns will carry the image best. However, a January presentation at the MEMS 2002 conference by Second Sight involved conducting posts one-tenth that diameter incorporated onto a chip surface.

When it comes to synthetic retina components, hopes are that smaller, more sophisticated structures will deliver the finest resolution at the smallest cost in power.


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