Electronic Retinas Help The Blind See Again

Bionic retinal implants give vision back to the blind…

Two British men have been come the first patients to be successfully implanted with electronic retinal implants. The new pioneering procedure has been shown to give vision back to the blind who have lost their sight due to Retinitis Pigmentosa.

Chris James, 54, who was declared legally blind 22 years ago, became the first to receive the operation to implant an electronic retina in the back of his eye, at the Oxford University Hospitals NHS Trust. The second patient, Robin Miller, 60, who lost his sight 35 years ago, received his implant days later.

The procedure is being pioneered by Robert MacLaren, Professor of Ophthalmology at the University of Oxford, and Mr. Tim Jackson, a consultant ophthalmic surgeon at King’s College Hospital in London. And the electrodes and external battery implants are being performed by Mr. James Ramsden of Oxford University Hospitals and Mr. Markus Groppe, an academic clinical lecturer at the University of Oxford, is performing

Retinal Bionic Implant Restores Vision

The device is design to replace the light-detecting cells in the retina, which deteriorate due to retinitis pigmentosa – an inherited condition that affects approx 1 in every 4,000 people in Europe.
The electronic retinas are just 3mm thick, and contain 1,500 light-sensitive pixels, which mimic the function of the photoreceptor rods and cones. When light reaches the retinal chip, pixels detects the waves and send electronic signals to the optic nerve and brain.

The surgery, which takes around 8 hours, involves implanting the device into the eye, running a thin cable to a control unit which sits behind the ear under the skin, and then attaching an magnetic external battery.
Professor MacLaren explains:

‘What makes this unique is that all functions of the retina are integrated into the chip. It has 1,500 light sensing diodes and small electrodes that stimulate the overlying nerves to create a pixelated image. Apart from a hearing aid-like device behind the ear, you would not know a patient had one implanted.’

The implants are manufactured by a Germany-based company aptly named Retina Implant. After 6 of year of development, the company published the results from its first human trial in Proceedings of the Royal Society B, November 2010. The study showed that using the implant; patients could recognize foreign objects and read words.

The early prototypes were not portable and only worked when linked up in the lab. The new devices in the British patients however, are completely portable.

While the technology appears to be effective in treating Retinitis Pigmentosa it must still undergo more trails to see if the procedure can be tailored to treat age-related macular degeneration, glaucoma or optic nerve disease.