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Chris
James, who has been blind for 25 years, saw a sudden pulsating
light in his left eye, like a camera bulb or a lighting flash.
Doctors had just switched on a wafer-thin, 3mm microchip
implanted at the back of his eye. At first all he could see was
light. Now he can distinguish shapes and might, in time, even be
able to recognize faces.
James’s experimental ‘bionic eye’ reacts to light, sending
an electronic signal that is picked up by the optic nerve and
processed by the brain into an image. The treatment could
partially restore the sight of thousands of sufferers of a
condition called retinitis pigmentosa, which causes the
photoreceptor cells at the back of the eye to deteriorate.
“As soon as I had this flash in my eye, it confirmed that my
optic nerves are functioning properly,” he said. “It was like
someone taking a photo with a flashbulb — a pulsating light.”
In March James, a 54-year-old from Wroughton, Wiltshire,
underwent an eight-hour operation at the John Radcliffe Hospital
in Oxford to have the chip implanted.
A second patient, Robin Millar, 60, a music producer, had
the surgery at Kingis College Hospital in London, as part of the
first UK clinical trial of the microchip, which has been
developed by the German company Retina Implant AG.
The surgery involves inserting a cable through the layers of
the eyeball to place the chip on an area of the retina the size
of a pinhead. The chip is connected to a power source implanted
under the skin behind the ear.
“What makes this unique is that all functions of the retina
are integrated into the chip,” said professor Robert MacLaren,
who carried out the first operation at Kingis College Hospital
in London. “It has 1,500 light-sensing diodes and small
electrodes that stimulate the nerves to create a pixillated
image.”
The patients only have a small range of black and white
vision: a rectangle about the size of a CD case held at arm’s
length. At present James can only make outshapes andlinescloseup
and it could takes weeks for the brain to begin to accurately
interpret the signals received from the microchip. |
