Wireless implant offers hope for blind

Researchers at the University of Strathclyde and Stanford University in California, have developed an artificial retina that could restore some vision to people with age-related macular degeneration (AMD).

The condition damages a layer of light-sensitive cells. One in eight people over 85 have AMD, while one in 500 people aged 55-64 also have it.

The device works like a solar cell generating electrical signals when hit by light, which stimulate the nerves left relatively unscathed by AMD. An infrared beam projects an image recorded by a camera through the eye onto the implant and as a result it does not require a power supply or any wiring.

Initial lab tests have been “encouraging”, according to research published in the journal Nature Photonics.

Dr Keith Mathieson, from Strathclyde University and a lead researcher on the project, said: “AMD is a huge medical challenge and, with an ageing population, is continuing to grow. This means that innovative, practical solutions are essential if sight is to be restored to people around the world with the condition.

“The prosthetic retina we are developing has been partly inspired by cochlear implants for the ear but with a camera instead of a microphone and where many cochlear implants have a few channels, we are designing the retina to deal with millions of light-sensitive nerve cells and sensory outputs.

“The implant is thin and wireless and so is easier to implant. Since it receives information on the visual scene through an infrared beam projected through the eye, the device can take advantage of natural eye movements that play a crucial role in visual processing.”

The device avoids the bulky wiring and processing needed by previous artificial retinas with relatively simple surgery needed to insert it.