A patient who is the first in the UK to receive the world’s most advanced ‘bionic eye’ has been able to read the time for the first time in more than five years.
Rhian Lewis, 49, can now read a clock, make out cutlery and look at her children’s faces again.
Surgeons at the Oxford Eye Hospital at Oxford’s John Radcliffe Hospital implanted a tiny light-sensitive electronic chip at the back of Rhian’s retina in her right eye as part of ongoing clinical trials led by Robert MacLaren, Consultant Vitreoretinal Surgeon and Professor of Ophthalmology in the Nuffield Department of Clinical Neurosciences.
Mother-of-two Rhian, of Cardiff, was diagnosed with retinitis pigmentosa – a disorder that destroys the light sensitive cells called photoreceptors in the retina – when she was five. She is completely blind in her right eye and has virtually no vision in her left eye as a result of the condition, for which there is no cure. But behind the destroyed photoreceptors she still had an intact optic nerve and all the brain wiring needed for vision, making it possible to restore vision if only a way could be found to substitute the function of the photoreceptors.
The wafer-thin retinal implant chip is inserted into the back of the eye to replace damaged photoreceptors in a delicate six to eight hour operation. The chip 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. The device is connected to a tiny computer that sits underneath the skin behind the ear. This is powered by a magnetic coil which is applied to the skin – from the outside this looks similar to a hearing aid. The device is switched on once everything has healed up after the surgery.
It takes time for users to learn to interpret the sight the implant provides as, for most of the trial patients, the parts of the brain responsible for interpreting vision have been dormant for a long time. When the device is first switched on they will often see flashes of light, but over a few weeks the brain converts those flashes into meaningful shapes and objects to build up an image. This image is black and white and grainy, rather like early television pictures, but for patients who have spent years without any sight at all this improvement can be life changing.
One test involved Rhian looking closely at a large cardboard clock to see if she could tell the time correctly. She has not been able to tell the time with her right eye in 16 years and for about six years with her left eye. She said: ‘Honest to God, that felt like Christmas Day’, when she felt the clock to reveal she’d seen 3’o’clock correctly.
The ‘bionic eye’ as a treatment for retinitis pigmentosa has been tested in Oxford since 2012 and during this time the hospital has worked in close partnership with Retina Implant AG to develop the technology with the hope that it will one day be ready for use across the NHS. A total of six patients will be taking part in the latest trial at the John Radcliffe Hospital.
Professor Robert MacLaren said: ‘Restoring sight to the blind using an electronic device presents huge challenges for the technology, the surgery and above all, the patient. But at the same time, we know the huge potential benefit if we can get it right. I am delighted that the trial has started so successfully with the excellent results we have had so far with Rhian.’
Muriel M. Delossantos