The first human clinical trials for a retinal implant have been a success – allowing those who had been blind to see again. About 200,000 people in the United States and Europe suffer from retinitis pigmentosa, a genetic disease that causes the slow degradation of eyesight starting from a young age, and often leads to blindness. The problem is that the genes in the eye are “programmed” to produce the wrong number of proteins that are needed for the cells. Over time, this causes the rods and cones in the eye end up dying, which is what leads to diminished and then lost eyesight. Right now, there are no approved treatments to either restore eyesight or even slow the progression of the disease, but that may soon change as teams of researchers and companies are working on curing the condition. One of those companies, Retina Implant, AG, has developed a new retinal implant that partially restores vision to people who’ve lost their sight to retinitis pigmentosa. A first round of human clinical trials began in 2005 and concluded in 2010. That trial showed extraordinary promise, and the results were published in Proceedings of the Royal Society B in November of 2010. The results showed that patients who received the implant had their eyesight partially restored to the point where they could distinguish objects and shapes and even read.
The implant itself is a small electronic chip, only 9 square mm, that’s implanted directly beneath the retina. The chip contains about 1500 electrodes and are powered inductively by transmitter coils placed under the skin. When light coming into the eye hits the electrodes, the chip converts the light into electricity, which then stimulates nerves in the retina. The stimulation is then perceived by the brain as sight. This differs from other implant technologies, which rely on cameras to capture and interpret the images. A second round of clinical trials has begun, and patients have already received the implants in Germany. The company is working to obtain approval to start new clinical trials in Pennsylvania and London. The first clinical trial only had eleven patients, but no complications arose from the procedure. By the end of the second round of clinical trials, 60 people will have tried the implant, which should provide a lot more data about its optimal use. What’s particularly exciting about this implant to me, though, is not only is it bringing back sight to the blind, but the manner in which it works should be able to be adapted to other types of blindness as well. A decade from now, this technology might be the equivalent of cochlear implants, which are steadily improving to provide a substituted form of hearing to those who are deaf or severely hard of hearing. I think this shows some pretty amazing potential.