German researchers use microchip to restore limited vision

Blind patients may soon be able to benefit from a wirelessly controlled microchip that has the ability to restore limited vision--allowing them to read letters and see faces.

A report from Proceedings of the Royal Society B describes the work of researchers from German medical technology company Retina Implant, who implanted an artificial retina in one eye of each participant in the trial, MIT Technology Review reports.

All patients in the trial had been blinded by either retinitis pigmentosa or another disease, all which the eye's photoreceptors to degenerate--so the device could also benefit patients with diseases such as macular degeneration, said Katarina Stigl, a clinical scientist at the University of Tubingen, who headed up the study.

During the trial, eight of the nine patients tested could perceive light while using the microchip, and five could detect moving patterns and objects such as cutlery, doorknobs and telephones, according to the report. Three could even read letters, but what had the biggest impact was being able to see their hands or the faces of a loved one.

"The very personal things ... are the most exciting for them," Stigl said to MIT Technology Review.

The device, a three-millimeter square chip with 1,500 pixels, contains a photodiode, picking up incoming light and getting amplified by a circuit. A cable running to the eye socket connects the implant to a small coil implanted under the skin behind the ear, making the system nearly invisible.

MIT Technology Review reports that earlier this week, another technology for restoring vision in patients with retinal degeneration, Second Sight's Argus II, was approved for use in the United States. They join the more than 20 groups around the globe working on visual prosthesis, according to Joseph Rizzo, a nuero-ophthamologist with the Massachusetts Eye and Ear Infirmary and Harvard Medical School.  

The FDA recently approved a bionic eye invention designed for people with retinitis pigmentosa. The technology uses a video camera attached to glasses that communicate with electrodes in the retina.

To learn more:
- read the Proceedings of the Royal Society B report
- read the MIT Technology Review article

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