Breakthrough implants 'reawaken' blind eyes

by Olga Deshchenko, DOTmed News Reporter | November 02, 2010
Retina Implant GA microchip
Researchers place two pieces of fruit in front of a blind patient who has received a subretinal electronic chip implant.

"The one on the right is longer," the patient says. "It's curving."

"It must be a banana," he says, a correct identification that's followed by applause and gleeful shouts of those in the room. "That's what it looks like," the man says, in a video accompanying a pioneering study.

The ability of blind patients to identify objects and, in other tests, read letters and combine them into words points to the success of the subretinal implant developed by a German-based company Retina Implant AG and tested at the University of Tuebingen.

The results of the company's first human-based clinical study, which is also the first clinical trial involving subretinal implants in humans, will be published in the Proceedings of the Royal Society B Wednesday.

Small but golden

The company's subretinal implant device is a light-sensitive and externally powered microchip that contains 1,500 electrodes and is implanted directly under a patient's retina. The chip is electrically powered and operates via transmitter coils that are attached to the skin, according to the study. As light enters the eye, the electrodes absorb it and convert it into electrical energy, stimulating the intact nerves in the retina. The simulation is then relayed to the brain through the optical nerve.

The implant is meant to help people with retinitis pigmentosa, one of the most common inherited forms of retinal degeneration. The condition affects photoreceptors of the retina, causing blindness due to the loss of light-sensitive cells. Approximately 100,000 people in the U.S. have the condition, according to the Foundation Fighting Blindness.

The subretinal implant differs from the epiretinal approach, which requires additional equipment such as a camera and a mounted transmitter to achieve the desired outcome. The subretinal method is generally more favored than the epiretinal approach.

The published results represent the first phase of the study. Based on the data, German scientists are now collaborating with other European countries to continue the research and, they hope, bring the device to market in the near future.

The next phase

When Dr. Robert MacLaren, professor of ophthalmology, University of Oxford and consultant ophthalmologist with the Oxford Eye Hospital, first saw the results of the study last year, the level of vision enabled by the implant surprised him.