Retinal Implants: Wait And See?

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Oct. 18, 2000 Wired.com News

Retinal Implants: Wait And See?

by Jessie Seyfer

Getting Optobionics to talk about whether its retinal microchips have proven successful in humans is like reading the bottom row of an eyechart from a mile away. It can't be done.

The company talked openly in late June when the solar-powered chips -– designed to restore sight to the blind -– were implanted into the eyes of several patients. But now Optobionics won't say anything except that the patients are fine, resting comfortably at home, with no complications.

"The world would love to know how they're seeing," said David McComb, chief information officer at the Wheaton, Illinois company. "But we plan to discuss our findings in a peer-reviewed journal, and not through the media."

Despite the fact that reporters and hopeful patients from around the globe have been continually asking for an update, the world will have to wait, McComb said.

One researcher working on a similar project at Johns Hopkins University says Optobionics' tight-lipped attitude may not be in the public's best interest.

Still, there are plenty of reasons to keep quiet, McComb said.

First, the company said it doesn't want to stir up false hope in patients who look to the Optobionics chip as a technological breakthrough that could finally bring them sight.

McComb acknowledges that patients have good reason to be excited. After all, the Optobionics study is the first Food and Drug Administration-approved clinical human trial, and it's the first time retinal chips have been implanted in people's eyes for longer than an hour.

But the company doesn't want to get ahead of itself, McComb said, and while the chips are designed to recreate sight for those whose retinas are damaged, the main goal of this clinical trial is simply to establish that the chips are safe.

"We apologize for not being able to make a more detailed announcement at this time," one of the chip's creators, Dr. Alan Chow, said in a statement. "We understand the great deal of interest from the press, the public, physicians, and researchers alike and we ask all to please be patient."

But one researcher who is working on a similar kind of implant at Johns Hopkins University suspects Optobionics has different reasons for being ambiguous about the trial's results.

Gislin Dagnelie, who works with a team of doctors and engineers on developing retinal chips, said the company may be keeping a tight reign on results because, as a privately held company, Optobionics needs to attract investors.

"They picture things as going forward, and I don't doubt they are telling the truth about their patients doing well," Dagnelie said. "But I think they are somewhat overemphasizing how close they are to having a working device."

Dagnelie said Optobionics is being deliberately quiet about a key aspect of their chips: that there's no way the patients could possibly see because the chip doesn't generate a strong enough visual signal to the brain. The Optobionics chips are powered by solar energy, while other chips amplify visual signals with the help of batteries or lasers.

"There's no way this device will give any useful vision," Dagnelie said. "It's not entirely honest toward patients who are looking for a cure. How realistic is this to characterize it as a working device if the light signals are so weak they couldn't possibly stimulate working cells?"

But McComb said that 10 years of prior research by the company on animal models has led them to believe a solar-powered chip could be successful.

Furthermore, the Optobionics chip is designed for people whose retinas have not been completely destroyed by disease, he said.

Chow was not available for further comment, but at a recent press conference he said that, even if successful, the chips could only bring about what they called "functional vision," or the ability to see shapes and forms, at most.

"Patients might see some shapes, some forms, or just light, but they wouldn't have reading vision or driving vision," Chow told the University of Illinois News Service.

It's possible an update on the Optobionics patients could be coming soon. Chow plans to speak Oct. 23 in Dallas at the American Academy of Ophthalmology conference. But, as before, Optobionics officials won't say what exactly they'll discuss.