New Surgery and Headset May Boost Vision
Fackelmann, Kathy A., Science News
A surgical technique may one day benefit people suffering from a blinding eye disease known as macular degeneration, according to a preliminary study of monkeys. If that approach doesn't work, another might: Researchers are working on a futuristic headset that would help people with impaired vision see the world on a personal television-like monitor.
Henry J. Kaplan and his colleagues at the Washington University School of Medicine in St. Louis wanted to find a way to correct age-related macular degeneration. In the so-called wet form of this disease, an abnormal growth of leaky blood vessels leads to injury of the macula -- the center ofthe retina that distinguishes details. This process, which usually strikes older people, gradually causes blurring of central vision and, in severe cases, blindness.
Kaplan's team began by operating on three healthy macaque monkeys. First, the surgeons made an incision in the retina. Then they used a pair of small, tweezer-like instruments to remove retinal pigment epithelial cells, the part of the macula damaged by scar tissue.
One hour after surgery, they sacrificed and examined one of the monkeys. As expected, they found a bare spot where they had removed part of the retina. However, three weeks later, they found the beginnings of a repair process in a second monkey. Nine months later, examination of the third monkey revealed new retinal pigment epithelial growth in areas that had been stripped during the operation. In addition, photoreceptor cells that had been disrupted by surgery had healed, suggesting that the blurry vision caused by the surgery had improved. Kaplan described the new findings last week at the annual meeting of the Association for Research in Vision and Ophthalmology, held in Sarasota, Fla.
While the surgeons couldn't test the monkey's vision, they did make another surprising observation at about the same time. An 80-year-old woman with macular degeneration, who had received a similar experimental operation at Washington University, came in for a checkup. Just before surgery, she had 20/400 vision, which made her legally blind in one eye. To make sure her vision didn't get any worse, Kaplan's group removed the scar-damaged retinal pigment epithelial cells. About a year later, her vision had improved to 20/60. …