Sharpening the bionic eye

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A decade of effort begins to pay off

By Roger Snodgrass

Helping the blind to see used to be a job for miracle workers. Now, an international science project is restoring the sensation of light in dozens of sightless eyes.

During a recent ceremony for employees of Los Alamos National Laboratory, a group of local scientists were recognized for their work on the Artificial Retina Project, which was honored this year with one of R&D Magazine’s annual awards.

To win one of the top technology awards in the world is one thing, but last week participants also found out that their project won the R&D “Editor’s Choice,” the top choice among all 100 awards.

During this decade, several national laboratories and dozens of researchers have pulled together under a Department of Energy umbrella to develop a sensory substitute, a visual prosthesis for the retina, the delicate tissues that line the back of the eye.

The project is primarily aimed at visually impaired individuals who have suffered either macular degeneration, an age-related disease that gradually destroys central vision or retinitis pigmentosa. Retinitis Pigmentosa is a genetic disease that damages the retina’s photoreceptor cells that connect to nerve cells, which in turn transmit visual information to the brain.

“This is not a project that’s unique to or even led by Los Alamos,” said John George, a biophysicist and neuroscientist and LANL’s principal investigator on the retina project. “We’re a part of what has become a very large team involving a number of DOE labs and university investigators.”

The work has evolved from Mark Humayun at the Doheny Eye Institute of University of Southern California. In 2002, Humayun’s team successfully implanted an array of 16 microelectrodes into the eye of a patient who had been blind for 50 years.

By 2009, 12 clinics in five countries had implanted 30 patients with the latest, 60-electrode version of the device made by Second Sight Medical Products, Inc.

“Even with the best systems, people remain legally blind,” George said. “But they do have some vision. They can in some cases navigate and find things.”

For people who have no perception of light at all, even this is an enormous improvement.

“For some of these people, just to have a sensation of light is a remarkable and emotional experience,” George said.

One patient participating in the clinical trials is described as having recognized the location of a full moon in the night sky. She can also tell which way a bright bar is moving across a computer screen.

A new 200-bit design is in the works, but the ultimate goal is an ultra-miniaturized instrument containing 1,000 or more electrodes. At that level of resolution, the artificial retina is expected to enable “reading of large print, unaided mobility and face recognition,” according to the project newsletter.

LANL’s role has focused on how the neural systems work, that connect the sensation of light and the brain.

“I’ve developed technology for more than a decade to allow us to make optical images of nerves as they fire, to actually make movies of nerves firing,” George said. “That allows us to see many nerve cells simultaneously, which is important for understanding how the retina encodes information, but also for understanding where the nerves are being stimulated.”

Los Alamos is also involved in thinking about the next generation of systems.

“There are a lot of immediate problems of getting the next system out,” George said. “We focus on the state of the art 10 years from now.”

A core of about four people work on the retina project at LANL, although others have contributed over the decade and perhaps 50 people are involved across the DOE complex.

“This is by far the leading effort in the world, and the current version is much more successful than anything else out there,” George said. “It is the beginning of a new approach to solving these kinds of medical problems.”

As the population ages, more people are affected by blindness or low vision. A study by the National Eye Institute published in April found 3.3 million Americans 40 years and older in that category. The researchers projected that number to grow to 5.5 million over the next 10 years, as low vision and blindness increases significantly with age.

The Artificial Retina Project was one of six awards in which Los Alamos National Laboratory participated this year.

In announcing the awards, Energy Secretary Steven Chu said that DOE-funded research won 46 of the R&D 100 awards given out this year.