The patients involved in the study, published in the Proceedings of the Royal Society, were blinded by retinitis pigmentosa (RP) and used the implant in and outside of their homes.
Retinitis pigmentosa is one of the most common types of inherited retinal degenerations and affects nearly 1.5 million people around the world. It is a progressive condition, becoming worse over time and causes severe vision problems as age progresses. Retinal implants provide hope for RP patients to regain their sight.
The participants documented having the ability to read letters uninhibited, decipher different objects such as telephones, recognize faces, and read signs on doors.
The electronic eye was manufactured by Retina Implant AG and is a 3 mm x 3 mm microchip that has around 1,500 electrodes. It is implanted under the retina creating artificial vision.
The chip needs electrical power to function. It acquires power inductively by transmitter coils put under the skin. The retinal implant then absorbs the light entering the eye, transforming it into electrical energy, stimulating the intact nerves inside the retina.
The stimulation is then transmitted to the brain through the optic nerve, resulting in an improved field of vision.
In this study, the majority of nine German patients were able to regain functional vision with their sub-retinal implant. The subjects were followed during a three to nine month observation period.
Professor Eberhart Zrenner, M.D., lead clinical trial investigator, Institute for Ophthalmologic Research at University Eye Hospital Tuebingen, Germany, said:
"The results of our first human clinical trial exceeded our expectations, and we are further encouraged by the results from the second human trial. As physicians, we are constantly seeking out the best treatment options for our most in-need patients, which most definitely includes those suffering from advanced-stage retinitis pigmentosa. This research provides additional evidence that our subretinal implant technology can help some patients with retinal degeneration regain functional vision and does so in a way that does not require externally visible equipment."
Last week, the FDA (Food and Drug Administration) approved the Argus II Retinal Prosthesis System, the first retinal implant to be approved in the USA. The device helps patients with advanced retinitis pigmentosa regain some sense of vision. The device consists of a tiny video camera, a VPU (video processing unit), a transmitter which is mounted on a pair of eyeglasses, and an implanted retinal prosthesis (artificial retina).
In a separate study published last year, it was reported that a diet high in omega-3 slows down retinitis pigmentosa progression.
Written by Kelly FItzgerald