March 11, 2009 For those suffering from degenerative eye diseases, abilities which most of us take for granted like following white lines on roads and sorting socks can have a huge impact on quality of life. "Bionic-eye" technologies that can artificially restore sight are creeping closer to reality and now one of the most promising systems to grace our pages - the Argus II Retinal Implant - is beginning to reap rewards in the real world with positive outcomes reported in the preliminary results of the device's feasibility study and personal stories beginning to emerge of the difference this technology can make to peoples lives.
Ron lost his sight 30 years ago as a result of retinitis pigmentosa, a group of inherited eye diseases that cause degeneration of the retina, and he is now one of 17 people across the world to be fitted with the Argus II as part of a three-year feasibility study. The results so far are promising, and the retinal implant technology is bringing hope to thousands of people with advanced retinal disease.
The second-generation Argus uses a camera and video processor mounted on sunglasses to send captured images wirelessly to a tiny receiver on the outside of the eye. In turn, the receiver passes on the data via a tiny cable to an array of electrodes which sit on the retina - the layer of specialized cells that normally respond to light found at the back of the eye.
When these electrodes are stimulated they send messages along the optic nerve to the brain, which is able to perceive patterns of light and dark spots corresponding to which electrodes have been stimulated. Second Sight Medical Products Inc, the developer of the retinal device, has been encouraged by the results of the trial to date. Robert Greenberg, MD, PhD, President and CEO said Second Sight “will be expanding the trial enrollment in order to strengthen our data, further demonstrate clinically meaningful performance and begin the process of seeking market approval”.
Preliminary results from the Argus II feasibility study were presented last month. According to Mark Humayun, MD, PhD, Professor of Ophthalmology at the Doheny Eye Institute at USC, there were no device failures and few serious adverse events occurred in the 17 subjects that have been enrolled in the study for an average of 14 months. Participants were frequently able to locate a door up to 20 feet away and walk to the end of a 20 foot line drawn on the floor.
Ron told the BBC: "For 30 years I've seen absolutely nothing at all, it's all been black, but now light is coming through. Suddenly to be able to see light again is truly wonderful.
"I can actually sort out white socks, grey socks and black socks," and has been able to help his wife with the washing, sorting white from coloured items and using the washing machine.
He cannot see shapes, but picks up "grades of light" and says his one ambition at the moment "is to be able to go out on a nice, clear evening and be able to pick up the moon."
Consultant retinal surgeon Lyndon da Cruz, who carried out Ron's operation said the patients were starting to get meaningful visual stimuli from the technology.
"The trial remains inspiring in terms of presenting a very real and tangible step forward in treating patients with total vision loss." said Mr da Cruz.
There is still a long way to go, and much hard work to be done, but it's very positive news for thousands of people like Ron.