Electrodes in brain may be breakthrough to restore sight

Published: July 9, 2007 | 6455th good news item since 2003

Electrodes inserted in the brain may point the way to restoring sight lost to eye disease or trauma.

The research in monkeys is in very early stages but has shown some promise, Harvard Medical School researchers reported in a recent issue of Proceedings of the National Academy of Sciences.

While researchers have worked on developing implants for the eye’s retina, John S. Pezaris and R. Clay Reid turned their attention to a portion of the thalamus that relays signals from the retina to the brain’s visual cortex.

They were able to get the brains of the monkeys to register a point of light by sending a signal down the electrodes – even though no actual light was visible, Pezaris said.

“We don’t know what it looked like because we can’t really ask them,” he said. “But there definitely was something.”

A single point of light may not sound like much, but Pezaris says the next step is to try to get eight points to register, which would allow the researchers to begin forming shapes such as vertical or horizontal lines.

“If that works we will try more and more and more,” he said. “At some point we hope to move into humans, and once we can do that, even on an experimental basis, the amount we will be able to learn will grow.”

That is a few years away, he said, but if all goes well it might lead to treatments for people who have lost their vision to accidents, cancer or diseases such as glaucoma and macular degeneration.

This technique hadn’t been tried because of the hard-to-reach location of the thalamus, but Pezaris said the advent of deep brain stimulation for treating Parkinson’s disease suggested that technique might be adapted.

Published in Science & Technology
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