Sight restored by subretinal implant shows promise

In results due to be presented at the ARVO meeting in May Retina Implant says its first human clinical trial has exceeded its expectations with some patients able to see objects and shapes so clearly they were able to combine letters to form words and recognize foreign objects.

The human trial, begun in Germany in 2005 comprised 11 retinitis pigmentosa (RP) patients who had lost their sight to the disease. The subretinal approach to implants means a chip is implanted underneath the retina in the macular region with the aim of allowing the natural way of processing light through the pupil to the retina to the optic nerve and on to the brain is restored.

“During the course of our first trial, we learned a great deal between our first and last patient, especially from patient 10 to 11,” said Dr Walter-G. Wrobel, president and CEO of Retina Implant, AG. “Paramount in this discovery was learning that using the subretinal approach to place the chip in the macular region provided superior clinical outcomes. The eleventh/last patient in the study was the only one to have the chip placed exactly in the macular region, and he was able to see more clearly than any other patient in the trial. Additionally, every patient tolerated the surgery well; no adverse events occurred.”

“As an ophthalmic vitreo-retinal specialist I have been following the artificial vision space for some time now, and I am particularly interested in the progress of Retina Implant's team,” said Dr Jay Federman of the Retina division of the Wills Eye Institute in Philadelphia, USA. “The results of the subretinal approach-implanting a 1,500 multi-electrode are very encouraging. It will be exciting to watch Retina Implant's subsequent clinical trials as well as scientists at both the Massachusetts Institute of Technology (MIT) and the Stanford University group who are also researching the subretinal approach and plan to commence human trials. I'm hopeful this breakthrough research will present the blind community with a viable treatment option in the coming years. This whole field is evolving, and I believe will continue to push beyond our existing capabilities.”

“I first noticed my eyesight was impaired at 16, and over a period of 16-17 years, my condition deteriorated to complete blindness,” said the 11th patient, a 45 year-old Finland-based male. “I knew there was a chance the implant wouldn't enable me to see anything, but I was willing to participate in the research with the hope I would regain some sight. When the microchip was turned on, I immediately was able to distinguish light from dark and see outlines of objects. As I got used to the implant, my vision improved dramatically. I was able to form letters into words, even correcting the spelling of my name. I recognized foreign objects such as a banana and could distinguish between a fork, knife and spoon. Most impressively, I could recognize the outlines of people and differentiate heights and arm movements from 20 feet away.”