Participants sought for bionic eye testing

Recruitment has begun for the first UK trial of a bionic eye which can restore sight to blind people.

The microchip implant has been tested in Germany, where it allowed patients to read letters and recognise objects.

Surgeons at King's College Hospital, London, are now preparing for a follow-up study in the UK. They hope to select six patients for the trial, due to get under way in March. Another six patients will be treated at Oxford Eye Hospital.

The device, made by German technology company Retina Implant AG, fits under the retina and works like a digital film camera. A 3mm sq array of 1,500 light sensors sends pulsed electrical signals to adjoining nerve cells, which relay the messages to the brain.

The implant is designed to help patients with retinitis pigmentosa, an inherited disorder which gradually destroys the retina. One in 3,000 people in the UK have the disease, some of whom can be blind by the age of 30.

The pilot trial in Germany achieved remarkable results with three blind patients, who were able to see shapes and objects for the first time since losing their sight.

Within days of surgery, the two men and one woman could locate a cup, saucer and different geometric shapes placed on a table.

One 46-year-old Finnish patient was able to walk around a room with confidence, tell the time from a clock, distinguish between subtle shades of grey and could even read his name.

Results from the trial were published last month in the journal Proceedings of the Royal Society B.

Surgeon Tim Jackson, who will head the King's College team, said: "We are delighted to be involved in testing this pioneering technology. The results demonstrated by the German team are genuinely impressive, and they represent an important step towards artificial vision that could greatly enhance the quality of life for people with an incurable, blinding disease.

"It is unquestionably an extremely exciting development."

Professor Robert MacLaren, from Oxford University, will be in charge of the Oxford arm of the trial.

The British study involves a more advanced version of the implant which has no external wiring. Power for the device is generated through an induction coil fitted behind the ear.

To qualify for the trial, patients have to be UK citizens and must have total or almost total loss of sight because of retinitis pigmentosa. They must also have previously been able to see for at least 12 years.

Anyone with enough vision left to see shapes or objects will not be eligible.

Those who fit the trial criteria can find out more from the King's College Hospital website: www.kch.nhs.uk.