By Dr Ananya Mandal, MD
In a medical breakthrough two blind men have regained partial sight for the first time in more than 20 years after receiving a “bionic eye”. Scientists said the first clinical trials of the microchip eye implant, which measures just 3mm across and is fitted behind the eyeball, have proved successful and “exceeded expectations”.
The news will offer fresh hope for people suffering from retinitis pigmentosa (RP) – a genetic eye condition that leads to incurable blindness. RP is a degenerative condition where the light-sensing cells in the retina produce the wrong amount of protein, leading to a gradual loss of function which results in total blindness. It affects up to 20,000 people in Britain.
According to experts developing the pioneering new technology, the first group of British patients to receive the implants were regaining “useful vision” just weeks after undergoing surgery, with one of them describing dreaming “in vivid colour” for the first time in 25 years.
Retina Implant AG, a leading developer of subretinal implants, fitted two RP sufferers with the wireless device in mid-April as part of its UK trial. The patients were able to detect light immediately after the microchip was activated, while further testing revealed that they were also able to locate white objects on a dark background. The digital chip operates when light falls on a sensor which is then converted into an electrical signal which is then picked up by nerves and transmitted to the area of the brain that processes images and where it converts the light into grainy black and white images.
The patients have been able to see the rough outline of shapes with doctors hoping that, in the future, once their brains have adjusted they will be able to recognise faces. The patients will undergo further testing as they adjust to the 3mm by 3mm device in the coming months.
Robin Millar, 60, from London, is one of the patients who has been fitted with the chip along with 1,500 electrodes, which are implanted below the retina. Mr Millar, a music producer, said, “Since switching on the device I am able to detect light and distinguish the outlines of certain objects which is an encouraging sign. I have even dreamt in very vivid colour for the first time in 25 years so a part of my brain which had gone to sleep has woken up.” The other Briton to have the implant was Chris James, 54, of Wroughton, Wiltshire. It has given him rudimentary vision which allows him to see the outline of shapes, but he is having to “learn” to see again after two decades without vision.
Ten more British sufferers will be fitted with the devices as part of the trial, which is being led by Tim Jackson, a consultant retinal surgeon at King’s College Hospital and Robert MacLaren, a professor of Ophthalmology at the University of Oxford.
The technology has been in clinical trials for more than six years with testing also taking place in Germany. Developers are now planning to seek commercial approval.
Dr Tim Jackson, a consultant retinal surgeon at King's College Hospital and one of the trial leaders, explained, “You can think of the retina as the film in the back of a camera. That has died away but the remaining connections are still intact and we can use these to transmit a signal to the brain. The chip replicates the action of the cells that have died away.”
Prof MacLaren, who fitted the first implant in the UK at the Oxford Eye Hospital, said, “It's the first time that British patients who were completely blind have been able to see something. In previous studies of restorative vision involving stem cells and other treatments, patients always had some residual sight. Here the patients had no light perception at all but the implant reactivated their retina after more than a decade.” Prof MacLaren said the results might not seem extraordinary to the sighted, but for a totally blind person to be able to orientate themselves in a room, and perhaps know where the doors and windows are, would be "extremely useful" and of practical help.
Nick Astbury, Chair of VISION 2020 UK, a global initiative for the elimination of avoidable blindness said, “This trial will bring hope to two million blind and partially-sighted people living in the UK. It is the first step on a long journey to help people with sight loss to see again and live independently.” David Head, head of charity RP Fighting Blindness, said, “The completion of the first two implants in the UK is very significant and brings hope to people who have lost their sight as a result of RP.”