Prosthetic Retina Restores Vision

Simplier synthetic retina uses photovoltaic chip

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Vision loss from age-related macular degeneration (AMD) can be a trying and frustrating experience. However, an interesting option may help some AMD patients regain sight.

Scientists from the University of Strathclyde in Scotland and Stanford University in California have created a thin and wireless prosthetic retina.

Though this isn't the first such prosthetic developed, but the newer one is less bulky, eliminates pesky wires and is easier to surgically implant.

Keith Mathieson, PhD, a lead researcher from the Institute of Photonics at the University of Strathclyde, noted that AMD is a huge challenge with an aging population, and innovative solutions are essential to restore vision to individuals affected by the condition.

The design of the prosthetic retina was actually inspired by a cochlear implant, a device surgically implanted at the base of the skull that can restore hearing in deaf individuals.

However, instead of a microphone as the cochlear implant features, the prosthetic retina includes a camera.

And instead of a handful of channels, the synthetic retina was designed to handle millions of light sensitive nerve cells and sensory outputs, Mathieson said.

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

The prosthetic retina is a thin silicon device that uses video goggles to convert pulsed near-infrared light to electrical current. This stimulates the retina and allows visual perception.

The retina stimulation works for AMD patients because neurons in the retina are relatively undamaged from the eye disease.

AMD instead causes the loss of photoreceptors, the cells responsible for capturing images.

The device also is wireless. Previously developed prosthetic retinas required wiring for receiving, processing and power. Scientists instead developed a method for a surgeon to create a small pocket beneath the retina, and then slip in photovoltaic cells which convert the energy.

Dr. Christopher Quinn, an optometrist with Omni Eye Associates called the development "a major improvement."

"The retina is a complex 10-layered neurological tissue and in macular degeneration, damage occurs essentially only in the outermost 3 layers. Any device that works with the undamaged retinal tissue, is compact enough to provide good resolution, and is easier to implant could potentially benefit patients with this common and often visually devastating condition."

Scientists are still working to further develop the technology. The positive results of the initial lab tests were recently published in Nature Photonics.

Reviewed by: 
Review Date: 
May 17, 2012
Last Updated:
July 30, 2012