IMAGE: The retinal implant is in place in the patient’s eye. (Image credit: University of Oxford)
Rhian Lewis, 49, a blind woman from Cardiff, England in the United Kingdom (UK) has described her joy as she could make out the time on a clock face by having some of her sight restored with an electronic "bionic" eye implant. Surgeons at Oxford Eye Hospital (Oxford, England) implanted a tiny light-sensitive microchip at the back of her right eye in an eight-hour operation.
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An inherited disorder meant she lost her sight in the eye 16 years ago. She has had the condition retinitis pigmentosa since she was age five, with her eyesight deteriorating as she got older--until she was completely blind in her right eye, with very limited vision in her left eye.
She underwent surgery in June, when surgeons implanted the retinal chip as part of a trial at Oxford's John Radcliffe Hospital. During follow-up tests, Lewis was asked to look closely at a large cardboard clock to see if she could tell the time correctly. She was able to tell it was three o'clock. Lewis was then taken to the cloisters of New College, Oxford, to see if she could make out its features. She said: "I walked up the street, and the lady from social services said to me to point out anything I thought might or might not be there. And the first thing I thought 'there might be something there,' there was a car, a silver car, and I couldn't believe it, because the signal was really strong, and that was the sun shining on the silver car."
Lewis is the first patient outside of Germany to be fitted with the latest generation of the light-sensitive chip. The implant--a 3 mm square array of about 1500 pixels that sends pulsed electrical signals to nerve cells--is connected to a tiny computer that sits underneath the skin behind the ear. This is powered by a magnetic coil on the skin. From the outside, it looks like a hearing aid.
According to a related story in R&D Magazine, since Lewis still had an intact optic nerve and the necessary brain wiring for vision, the scientists just needed a device to substitute for the photoreceptors that Lewis lost as a result of having retinitis pigmentosa--an incurable disease that causes retinal degeneration as photoreceptor cells die off. The chip was developed by engineering firm Retina Implant (Reutlingen, Germany) and captures the light entering the eye to stimulate the nerve cells of the inner retina to deliver signals to the brain through the optic nerve.
When the device is first switched on, patients see flashes of light, but over a few weeks the brain learns to convert those flashes into meaningful shapes and objects. The images can be black and white and grainy but still have the power to transform lives.
SOURCE: BBC News; http://www.bbc.com/news/uk-wales-35226373