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Bionic breakthrough in sight with an Australian first

Extracts from : http://www.smh.com.au/news/science/aust ... ntentSwap1

AUSTRALIA'S first bionic eye will be implanted by two Sydney researchers.

Using the same cochlear technology that allows the deaf to hear, the device aims to restore basic vision in patients with degenerative eye diseases, allowing them to walk without a cane or guide dog and differentiate between night and day.

Minas Coroneo and Vivek Chowdhury, from Sydney's Prince of Wales Hospital, say the visual prosthesis could be the first - and cheapest - to hit the world market.

Rather than "reinventing the wheel", they have adjusted the cochlear implant to allow patients to perceive light, rather than sound.

But while others - including two rival Australian groups - are working on a prosthesis to be implanted inside the eye on the retina (intraocular), Professor Coroneo's and Dr Chowdhury's device puts electrodes on the outer wall of the eye (extraocular).

The two ophthalmologists, who formed the Australian Bionic Eye Foundation, say their approach is safer, reversible and won't threaten what little vision some people have.

Four overseas groups have implanted prototypes in humans but have failed to prove benefit, or have had serious complications. In 2006, Professor Coroneo and Dr Chowdhury conducted a clinical trial of 20 patients to determine which types of blindness would respond to stimulation. In many conditions causing blindness, the retina is damaged but the nerves connecting to the brain remain largely intact and can be activated by electrical stimulation. It won't work for people born blind.

Following successful animal studies this year, the researchers have drafted three surgeons to soon implant the device in a cadaver.

Other researchers are focusing on experiments with more sophisticated, intraocular devices that may help sight-impaired people read.