Implanted chip `allows blind people to detect objects`
Baku, November 3 (AZERTAC). A man with an inherited form of blindness has been able to identify letters and a clock face using a pioneering implant, researchers say.
Miikka Terho, 46, from Finland, was fitted with an experimental chip behind his retina in Germany. Success was also reported in other patients. The chip allows a patient to detect objects with their eyes, unlike a rival approach that uses an external camera. Details of the work are in the journal Proceedings of the Royal Society B. Professor Eberhart Zrenner, of Germany`s University of Tuebingen, and colleagues at private company Retina Implant AG initially tested their sub-retinal chip on 11 people. Some noticed no improvement as their condition was too advanced to benefit from the implant, but a majority was able to pick out bright objects. However, it was only when the chip was placed further behind the retina, in the central macular area in three people, that they achieved the best results.
Two of these had lost their vision because of the inherited condition retinitis pigmentosa, or RP, the other because of a related inherited condition called choroideraemia. RP leads to the progressive degeneration of cells in the eye`s retina, resulting in night blindness, tunnel vision and then usually permanent blindness. The symptoms can begin from early childhood. The best results were achieved with Mr Terho, who was able to recognise cutlery and a mug on a table, a clock face and discern seven different shades of grey. He was also able to move around a room independently and approach people.
In further tests he read large letters set out before him, including his name, which had been deliberately misspelled. He soon noticed it had been spelt in the same way as the Finnish racing driver Mika Hakkinnen. "Three or four days after the implantation, when everything was healed, I was like wow, there`s activity,". "Right after that, if my eye hit the light, then I was able to see flashes, some activity which I hadn`t had. "Then day after day when we started working with it, practising, then I started seeing better and better all the time."
