New eye implants for the blind restore some sight
November 4, 2010
Lesley Ciarula Taylor
STAFF REPORTER
A 35-year-old blind man in Holland can see his fiancée’s face for the first time through a tiny electronic implant developed by scientists in Germany.
Another blind man, Miikka Terho, 46, can now pick out the shape of a plate and cutlery on a table, read large letters, and distinguish a banana from an apple.
“This may not mean much to us, but for someone who has completely lost their vision, this is something they never thought could happen,” Dr. Eberhart Zrenner told the Star on Thursday.
“Another patient wrote to tell us: ‘I have seen today a sunflower in my garden.’ That gives you a lot of emotional strength to push it as much as you can.”
Zrenner and his team at the University of Tuebingen have been pushing since 1995 to reverse blindness in people with retinitis pigmentosa, an incurable, often hereditary loss of sight that afflicts 1.5 million people worldwide.
“It’s a miracle brought on by science,” Joe Grech of Vancouver said about the German breakthrough. “I was ecstatic when I read about it.”
Grech’s eldest daughter, 9-year-old Olivia, was diagnosed with retinitis pigmentosa at age 5. Her vision has degenerated to the night blindness stage. Grech pins his hopes on science forestalling complete blindness.
“This stream in particular is very uplifting,” said Grech, a board member of the Foundation Fighting Blindness.
The trials he’s referring to, published in the Proceedings of the Royal Society B, restored some vision in nine of the 11 patients.
“We learned the implant had to be under the retina. If you do it right under the retina, the patient can move his eyes. There is no camera outside. They would be able to see nicely a few days after surgery.”
U.S. research for the companySecond Sight has created a similar result with a camera attached to eyeglasses.
Using the same technology as that in cochlear implants for people who are deaf, the German scientists embedded a transmitter in the bone behind the ear and a microchip with 1,500 independent elements directly behind the retina.
For two patients whose nerve-cell damage was extensive, the implants didn’t work. The best results came in the final three patients, including Terho, whose chip was in the central macular area behind the retina.
“As long as we have 25 to 50 per cent of the cells left in the retina, it can work,” said Zrenner.
Although Terho, 46, appears in the video to be wearing a visor, he is actually sporting drugstore reading glasses, as anyone over age 45 might wear.
The images he sees, Terho told the BBC, are in black and white. It took many days of practice to kick-start his retina, idle for 15 years. From a flash of light four days after surgery, he could eventually distinguish all parts of the letter L.
Zrenner is cautious about the progress and the results.
“We are not aiming at reading. Patients are able to localize objects, see the schnitzel on the table or, for the lucky ones with an optimal situation, the headlines in the newspaper.”
The next stage of research involves a trial of 50 patients at six centres throughout Europe.
“It will be another two more years until we have the confidence to put it into the hands of other surgeons,” said Zrenner.
The chip lasts two years, but as the science develops, chip life will likely grow, too.
“We feel a bit like the Brothers Wright,” he said. “They showed that airplanes can fly, although it was only 200 metres. It was a few years until Lindberg crossed the Atlantic and a few more years after that until you could buy an airline ticket.”
“The data show that an electronic solution is possible.”
Other work to combat retinitis pigment’s involves stem-cell studies in the U.K. and genetic research at the University of British Columbia.
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