Blind patients in Manchester join global trial of 'bionic eye'
Eye surgeons at Manchester Royal Eye Hospital have implanted an intraocular electronic retinal prosthesis or 'bionic eye' in two Manchester patients who became blind due to advanced retinitis pigmentosa – an inherited and degenerative disease of the retina.
The surgery was carried out by Mr Paulo E Stanga, a consultant ophthalmologist and vitreoretinal surgeon and Reader in Ophthalmology at The University of Manchester and Manchester Biomedical Research Centre, and his team. It is part of a pioneering international trial of the artificial retina, which is intended to help some blind people regain a degree of vision. The Manchester patients are two of only 25 people worldwide to participate in the trial to date.
Using ArgusTM II technology, developed by Second Sight® Medical Products, Inc. (Sylmar, CA, USA) the implant aims to restore a basic level of useful vision, in the form of spots of light and shades of light and dark, to people with very severe retinitis pigmentosa.
The technology consists of a tiny camera and transmitter mounted in a pair of glasses. This camera transmits a wireless signal via a small processing device to an ultra-thin electronic receiver, an electrode panel that is implanted in the eye and attached to the retina. The electrodes are intended to stimulate the remaining retinal nerves, allowing a signal to be passed along the optic nerve to the brain, which perceives patterns of light and dark spots corresponding to which electrodes are stimulated.
“We are very encouraged by the trial’s results so far,” says principal investigator Mr Stanga. “The 'bionic eye' operations went exactly according to plan and both patients are doing well, although it will be several months before the functional outcome is fully known. We hope the implant will improve each patient’s orientation and mobility, spatial localisation, and motion detection, perhaps giving these patients navigational vision in familiar and unfamiliar environments.
“The trial remains inspiring in terms of presenting a very real and tangible step forward in treating people with total vision loss. These are early days and continued testing will be crucial in determining the success of the new technology. We are delighted to be able to offer participation in this pioneering international trial in the North of England, and our thanks go to Kevin Johnson, the Chair of the British Retinitis Pigmentosa Society in the North West, for their help in supporting the trial."
Extensive testing is just beginning on the two Manchester patients as the implant and video camera link are turned on to try and optimise retinal stimulation.
Manchester Royal Eye Hospital is also recruiting new subjects to the trial. To be eligible, patients must meet the following inclusion criteria:
Be aged 18 years or older at the date of enrolment.
Have a confirmed history of retinitis pigmentosa.
Have a visual acuity of logMAR 2.3 or worse in both eyes.
Have a functional optic nerve.
Have a memory of former useful form vision in the worse-seeing eye.
Understand and accept the obligation to attend all scheduled follow-up visits.
GPs and other professionals can get more details about referring patients to the trial from Kate Barugh on 0161 276 5615 or firstname.lastname@example.org.
Further information about retinitis pigmentosa is available from the British Retinitis Pigmentosa Society at www.brps.org.uk.