Retina Implant, AG, a leading developer of electronic implants to treat blindness, today announced successful results from the company’s first human clinical trial. The company is now setting up a UK trial of the implant. The results achieved in the 11 patients involved in the preliminary study far exceeded the company’s expectations. In fact, some patients were able to see objects and shapes clearly enough to read large letters and recognize words. Although other companies have developed retinal implants, until now the technology facilitated the ability to see light and outlines of objects, but did not produce a level of sight that enabled patients to read. Retina Implant’s clinical trial began in Germany in 2005 and has involved 11 patients who lost their sight due to retinitis pigmentosa (RP). The UK clinical trial will be led by Professor Robert MacLaren, Professor of Ophthalmology at the University of Oxford and a consultant retinal surgeon at the Oxford Eye Hospital and includes Mr Tim Jackson, a consultant retinal surgeon at King’s College Hospital in London.
There are two main approaches to retinal implants currently being developed by scientists across the globe: epiretinal and subretinal. Both electronic implants stimulate the retina, which is a light sensitive sheet of nerve cells at the back of the eye, similar to the film of a camera. In diseases such as RP and macular degeneration, the retina itself degenerates and loses its light sensitivity, rendering affected patients blind. The ‘epiretinal’ approach involves sticking an electronic implant in front of the retina to stimulate the nerve cells. The surgery to do this is more straightforward, but the epiretinal implant is not itself light sensitive and needs to be connected to a camera outside the eye, often mounted on the patient’s spectacles. The new ‘subretinal’ approach developed by Retina Implant AG involves placing the electronic device underneath the retina, which is technically challenging but stimulates the nerve cells in a more natural position. This may explain the dramatic visual results revealed by the company today. Furthermore the subretinal device is itself light sensitive, with a 1500 pixel array. This is stimulated by the natural image focused by the eye which completely does away with the need for an external camera.
“I have been working in developing new treatments for patients with retinal diseases for many years and I was initially skeptical about the role of electronic devices. However, this recent work by the Retina Implant team is very impressive indeed and I would now certainly consider this technology as a viable treatment option for patients blind from RP,” says Professor MacLaren. “It’s much more logical to place the implant underneath the retina where the residual neurons are orientated towards the implant electrodes, because this should equate to a much higher pixel resolution. Another development is that the implant itself is light sensitive, which I would view as a major technological advance because the whole device can be contained within the eye. A power supply is fed through a battery behind the ear similar to a hearing aid. This represents a true fusion of an electronic interface with the human central nervous system and we are likely now to learn a lot more about this technology as the trial progresses.”
Retinitis pigmentosa (RP) is one of the most common forms of inherited retinal degenerations affecting approximately 200,000 people in the world. A progressive condition that gets worse over time, RP typically causes severe vision problems in adulthood. While there are currently no approved treatment options that can restore vision for RP patients or impede the progression of the disease, retinal implants represent tremendous promise for enabling RP patients to regain sight.
“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.”
“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.”
Retina Implant is presenting results of this clinical trial at the Association for Research in Vision and Ophthalmology’s (ARVO) annual meeting May 2 – 6 in Fort Lauderdale, Fla.
Retina Implant, AG