A miniature telescope implanted in the eye could help people with vision loss due to late stage macular degeneration very soon. Clinical trials of the device, which is about the size of a pencil eraser, suggest that it can improve vision by about three and a half lines on an eye chart.
"This is one of the few options for people with end-stage macular degeneration," says Kathryn Colby, an eye surgeon at the Massachusetts Eye and Ear Infirmary in Boston, who helped develop the surgical procedure used to implant the device.
Macular degeneration is the leading cause of blindness in people over 65. The disease attacks the center of the retina, called the macula, which is especially important for reading, watching television, and recognizing faces. Although there are some treatments to slow the progression of the disease, there is no treatment currently available for patients in the later stages of the disease, who have irreversible damage to the macula.
The implant, developed by VisionCare Ophthalmic Technologies, a startup company based in Saratoga, California, consists of two lenses within a glass tube. Once inside the eye, it functions as a fixed telephoto lens, working in conjunction with the cornea to project, onto much of the retina, a magnified image of whatever the wearer is looking at.
Since only the central parts of the retina are damaged in the disease, magnifying the image in the eye allows the retinal cells around the macula to detect the object and send the information to the brain (these cells are often involved in peripheral vision and typically generate low-resolution visual information compared to macula cells, but magnifying the image also makes it easier for the cells to interpret it).
"This change in vision is important to patients," says Allen Hill, PCEO of VisionCare. In addition to improving vision, "it offers the possibility of maintaining normal eye contact, which is essential for social interaction," says Eli Peli, a scientist at The Schepens Eye Research Institute.
Source: Technology Review