Wyatt team reports retinal implant testing within sight

September 24, 2009

To test a new technique for creating micromachines, MIT researchers deposited films of gold on a sheet of plastic; grooves in the plastic are visible as a series of horizontal lines.  Image: Corinne Packard and Apoorva Murarka

EECS Professor John Wyatt, Principal Investigator in the Research Lab of Electronics, RLE, at MIT and head of both the Retinal Implant Research Group in RLE, and the 20-year multiteam effort known as the Boston Retinal Implant Project, has recently reported a new prototype retinal implant that promises testing in blind patients within three years.

As reported Sept. 23 by the MIT News Office, the eye implant is designed for people who have lost their vision from retinitis pigmentosa or age-related macular degeneration, two of the leading causes of blindness. The retinal prosthesis would take over the function of lost retinal cells by electrically stimulating the nerve cells that normally carry visual input from the retina to the brain.

Such a chip would not restore normal vision but it could help blind people more easily navigate a room or walk down a sidewalk.

Patients who receive the implant would wear a pair of glasses with a camera that sends images to a microchip attached to the eyeball. The glasses also contain a coil that wirelessly transmits power to receiving coils surrounding the eyeball. Their goal is to produce a chip that can be implanted for at least 10 years.

When the microchip receives visual information, it activates electrodes that stimulate nerve cells in the areas of the retina corresponding to the features of the visual scene. The electrodes directly activate optical nerves that carry signals to the brain, bypassing the damaged layers of retina. In the latest version, described in the October issue of IEEE Transactions on Biomedical Engineering, the implant is attached to the outside of the eye, and the electrodes are implanted behind the retina.

The Boston Retinal Implant Project includes scientists, engineers and ophthalmologists from Massachusetts Eye and Ear Infirmary, the Boston VA Medical Center and Cornell as well as MIT. The research is funded by the VA Center for Innovative Visual Rehabilitation, the National Institutes of Health, the National Science Foundation, the Catalyst Foundation and the MOSIS microchip fabrication service.

Patients have told the researchers that what they would like most is the ability to recognize faces. "If they can recognize faces of people in a room, that brings them into the social environment as opposed to sitting there waiting for someone to talk to them," Shawn Kelly, member of the RLE Retinal Implant Research Group and of the Boston Retinal Implant Project related to the MIT News Office.

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