New Retinal Implant Gives Hope To Sufferers Of Retinitis Pigmentosa

A new retinal implant has been proven to help people suffering from a blinding genetic disease called retinitis pigmentosa to recognise common objects.

The study, presented at the annual meeting of the American Academy of Ophthalmology, is titled ‘The Use of the Argus II Retinal Prosthesis to Identify Common Objects in Blind Subjects With Outer Retinal Dystrophies (PO181).’

Researchers developed a retinal prosthetic device, called Argus II, which includes a miniature camera set into the patients’ glasses which sends data to a processing unit that the patient wears. This unit converts visual information into instructions, which are are then sent to a retinal implant containing 60 pulsing electrodes. The pulsations stimulate retinal cells to transmit the visual data via the optic nerve to the brain where it creates the perception of light patterns.

The study tested eight people wearing the device, asking them to identify metallic or white objects against dark backgrounds. They were then asked to identify the same objects with enhanced outlines. The tests were carried out using three modes of work for the system – standard, scrambled, and switched off. For non-highlighted objects, the results showed that while the rate of correct object identification was 12.5% with the device switched off, it rose to 32.8% when it was in standard mode, and stood at 26.2% in scrambled mode. For highlighted objects, the percentages were, 9.4%, 41.4%, and 20.7%, respectively.

Retinitis pigmentosa affects the ability of the retina to react to light and is currently incurable. Among the other devices that help sufferers are microchip implants, electrical stimulation therapy, implanted capsules with time-released medicines, and nutrition therapies aiming to limit retinal damage. There are also gene therapies which aim to halt or reverse the development of the condition.