Retinal Implants: Helping the Blind to See

By: | February 21st, 2013

Yesterday the US Food and Drug Administration (FDA) approved Second Sight’s Retinal Prostheses System giving hope to those with a genetic condition called “Advanced Retinitis Pigmentosa” (ARP) which damages light-sensitive cells in the retina.

Second Sight has been developing this technology for 20 years and received more than $200 million from the National Eye Institute, the Department of Energy, the National Science Foundation and private investors.

In a healthy eye rod and cone photoreceptor cells inside the eye convert light into electrical signals and the optic nerve sends them to the brain’s visual cortex where they are processed.  ARP severely damages the retinas photoreceptors.

To circumvent the damaged cells a 3×3 millimeter, 0.1 millimeter thick microelectronic chip with 1,500 light-sensitive photodiodes connected to amplifiers, a 60 electrode prosthesis inserted beneath the fovea  and a small video camera are implanted.  A video processing unit transforms video images to digital electronic data that are wirelessly transmitted to the brain via the retinal prosthesis generating partial vision by stimulating healthy nerve cells in the retina.

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The system does not fully restore vision but allows users to perceive images and movement. Second Sight is working to adapt the technology to someday help people who have age-related macular degeneration.

The Argus II will be available in clinics beginning in 2013 as surgeons become more familiar with the device.

David Russell Schilling

David enjoys writing about high technology and its potential to make life better for all who inhabit planet earth.

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