Retinal implants have restored the sight of two British men, blinded by retinitis pigmentosa.
54-year-old Chris James and Robin Millar, 60, had the electronic retinas implanted in March as part of a clinical trial, coordinated by Oxford University and performed at Oxford Eye Hospital and King’s College Hospital in London.
Both men have retinitis pigmentosa, a rare hereditary condition that causes gradual deterioration of the light-detecting cells in the retina, which can lead to blindness. The electronic retinas are implants containing light detectors designed to replace the lost light-detecting cells.
Immediately following the procedures, when the implants were switched on, both men were able to detect light and are now beginning to use their restored vision.
Bionic Vision Australia is on track to commence patient tests with its own full wide-view bionic eye next year…
Mr. James said he had been completely blind in his left eye for more than 10 years and could only distinguish lights in his right eye.
When his electronic retina was switched on for the first time, three weeks after the operation, he was able to distinguish light against a black background in both eyes. He now is able to recognise a plate on a table and other basic shapes, and his vision continues to improve.
“It’s obviously early days but it’s encouraging that I am already able to detect light where previously this would have not been possible for me. I’m still getting used to the feedback the chip provides and it will take some time to make sense of this. Most of all, I’m really excited to be part of this research.”
Mr. Millar also said he could detect light immediately after the electronic retina was switched on, and that useful vision was beginning to be restored.
Unique Device
Developed by Retina Implant AG in Germany, each retinal implant contains a microchip containing 1,500 tiny electronic light detectors.
Before the implant can be inserted, a power supply is implanted and buried under the skin behind the ear. The electronic retina is then inserted into the back of the eye, stitched into position, and connected to the power supply. The patient’s optic nerve is then able to pick up electronic signals coming from the microchip.
Professor Robert MacLaren, who is leading the research, said the implant is unique in that “all functions of the retina are integrated into the chip”.
“It has 1,500 light-sensing diodes and small electrodes that stimulate the overlying nerves to create a pixellated image. Apart from a hearing aid-like device behind the ear, you would not know a patient had one implanted,” Prof. MacLaren said.
Prof. MacLaren said while the team was delighted with the initial results, the vision gained by the two men is “different from normal and requires a different type of brain processing”.
“We hope, however, that the electronic chips will provide independence for many people who are blind from retinitis pigmentosa.”
The early success raises hope for the treatment of the disease, which is currently incurable. Up to 10 further patients with retinitis pigmentosa will now be treated as part of the trial.
In Victoria, Bionic Vision Australia is on track to commence patient tests with its
own full wide-view bionic eye next year. Professor Anthony Burkitt, who heads that study, said the results coming out of Germany are pleasing.
“We are excited to see that a number of our international colleagues have reached a point where implants are already being used to improve vision for people with retinitis pigmentosa,” he said.
“Many of these devices work differently to those we are developing at Bionic Vision Australia, but we closely monitor and interact with research teams all over the world in order to develop advanced retinal implant technology.
“Nuances regarding where the implant is placed, how electrical stimulation is delivered to the retina, and the surgery itself, all make a difference in the resulting benefit that patients receive from the implant.
“We look forward to trialling our first device with patients next year and continuing to work with the Australian vision impaired community,” Prof. Burkitt said.
