Years after macular degeneration forced Sheila Irvine to mail back her driver’s license and, in her words, “cried all day,” the Pittsburgh resident is getting something back she thought was gone for good: the ability to pick out shapes and even read letters again. She is one of several people in a clinical trial testing a tiny implant called PRIMA, a device that combines a coin-sized chip under the retina with augmented-reality glasses and is being evaluated by surgeons in Pittsburgh and across Europe.
An international clinical study published last October in the New England Journal of Medicine found that the PRIMA system produced what researchers called clinically meaningful gains in central vision for about 80% of participants who completed a 12-month follow-up. That worked out to 26 of 32 patients showing significant improvement. Most serious side effects appeared early and later resolved. The open-label trial enrolled 38 people across 17 centers and compared how well they could read letters, recognize shapes, and improve standard visual acuity scores with the prosthesis turned on versus switched off.
How the chip and glasses create form vision
The implant itself is a hair-thin silicon microarray that is roughly 2 millimeters on a side and about 30 microns thick. Video from the external glasses is captured and sent to a small pocket processor, which converts the image and projects it back into the eye as invisible near-infrared light that lands on the chip. The microarray then turns that light into electrical signals that stimulate the retinal neurons that are still functioning.
Early feasibility work described an array made up of 378 pixels spaced at 100 microns per pixel, while developer summaries and some local accounts describe the current device as having approximately 400 electrodes. The glasses include zoom and contrast controls, and the software that runs the system can be updated without additional surgery. Rehabilitation training after activation is a big part of learning to use the artificial vision, and patients typically go home the same day as the operation, according to Ophthalmology Science.
Pittsburgh trial volunteer’s account
“My worst day was, I sent my driving license back and I cried all day,” Irvine told local reporters, describing the emotional gut punch of losing central vision and the relief of later being able to make out edges again once the device was activated. Dr. José-Alain Sahel, a senior author on the international trial and chair of ophthalmology at the University of Pittsburgh School of Medicine, called the results “an important step,” while stressing that the technology still needs fine-tuning to deliver better resolution. Those details and Irvine’s account were reported by WTAE.
Where access and approvals stand
According to BusinessWire, Science Corporation, which acquired the PRIMA program from Pixium Vision, has been moving the implant toward regulatory review in Europe and has created a patient registry as part of its commercialization plans, according to a company release. Sahel has said there are ongoing discussions with the U.S. Food and Drug Administration about letting a limited number of patients each year receive the implant while the device moves toward broader approval, a point described in local reporting and interviews. For more on the company background and regulatory push, see the release and a University of Pittsburgh summary…