Newly developed chip implant in eye 'helps blind people to see'

Posted Nov 3, 2010 by Kev Hedges
Ophthalmologists in Germany have fitted a pioneering experimental chip behind the retina of a man born with an inherited form of blindness. He can now distinguish bright objects and identify simple cutlery items like knives, forks and spoons.
Miikka Terho, 46, from Finland, was fitted with the chip behind his retina in the University of Tübingen in Germany. He can read letters, tell the time and identify a cup and saucer on a table. The University's Professor Eberhart Zrenner, and colleagues at private company Retina Implant AG initially tested their sub-retinal chip on 11 people, the BBC reports.
Mr Terho was one of three patients who had the chip inserted under part of the retina called the macula, where the highest concentration of light-sensitive cells are found. He lives in Finland and developed a condition called retinitis pigmentosa, a hereditary disease that causes light-sensitive cells, or photoreceptor cells, in the eye, to steadily and irreversibly die off. His night vision began to fail when he was 16 and he was severely blind in both eyes by 35. Unaided, he now has just enough peripheral vision to tell night from day.
There is good news for those suffering from blindness in Britain as teams led by consultant retinal surgeons Robert MacLaren at Oxford eye hospital and Tim Jackson at King's College hospital will implant the chip into the first UK patients in a multicentre trial starting early next year, according to the Guardian.
Mr Terho, meanwhile, is very excited by his new lease of vision, he said:
I've been completely blind in the central area for about 10 years. I had no reading ability and no way of recognising anybody any more. When the chip was first turned on, I just saw flashes and flickering. It didn't make any sense. But in a matter of hours, everything started to get clearer and clearer.
When I looked at people for the first time, they looked like ghosts. I knew it was a person, but they were hazy. Then things got sharper.
It was such a good feeling to be able to focus on something, to see something right there, and maybe even reach out and grab it. I wasn't able to identify what was in front of me on the street, but I knew when something was there, so I didn't walk into it.
The technique is suitable for a range of eye conditions that affect the rod and cone cells; these cells detect light and then convert the light into electronic signals that travel through the optic nerve and into the brain. It is because of this optic nerve use, that the technique is unsuitable in certain eye diseases. Glaucoma patients, for example, have damaged optic nerves caused by high intraocular pressure. However, patients with etinitis pigmentosa, choroideraemia and age-related macular degeneration are all conditions that do affect these cells while leaving other components of the eye relatively untouched.