Retinal implant offers rudimentary sight to blind

Second Sight's "bionic eye" implant, the Argus II Retinal Prosthesis System, has been implanted into two blind patients at London's Moorfields Eye Hospital by Dr Lyndon da Cruz and team. The patients were the first British subjects of a multinational Phase I clinical trial, being conducted in Britain, the US and Mexico.

The implant is designed to combat retinitis pigmentosa (RP). Sixty electrodes, which conduct information acquired from an external camera to the retina, provide a rudimentary form of sight (motion and light and dark) to implanted subjects. The first generation of the implant, the Argus 16, comprised 16 electrodes and was tested in six RP patients between 2002 and 2004; the next generation device, currently under development, will have 1000 electrodes, allowing facial recognition.

Four more subjects have been recruited into the US arm of the trial. If the trials go well, it is hoped that the implant will be widely available within five years.