
Brain trauma patients with certain visual deficits, including gaps in the visual field, can gain back a good portion of sight by using a novel computer program that retrains brain circuits, scientists have found.
The device, developed by German doctors a decade ago, is making a debut in the US at Columbia University Medical Center. Dr Randolph Marshall, a neurologist at Columbia, has tested it with 55 patients, most of whom had at least some restoration of sight. 8216;8216;For patients who experience a 10 to 20 percent improvement, it can be the difference between seeing a piece of paper or just half of it,8217;8217; Marshall said.
Sitting in front of a computer screen, patients fixate on a dot as stimuli appears around it. They press a keyboard button to respond to the geometric shapes that move in patterns across the screen. They do this six days a week for 20 minutes, twice a day. The customised treatment to stimulate their damaged neurons takes six months, and the results are lasting, Marshall said. He said that about 65 percent of patients report some improvement. Studies have shown that blind fields are reduced in size by 20 percent.
8216;8216;We are now trying to figure out what is going on in the brain,8217;8217; said Marshall, who is working with the makers of the device, Nova Vision, to design ways to measure brain plasticity or ability to self-repair. 8216;8216;We think that parts of the brain are taking over for the damaged areas.8217;8217; The therapy is not offered right away because there is a small window of time when spontaneous recovery from stroke occurs. Vision problems occur during the actual episode and usually don8217;t get worse over time.
The six-month treatment costs 6,000, which includes a detailed mapping of the patient8217;s visual field. The therapy is built around this map. Scientists suspect that visual restoration therapy restores the partially damaged neurons that are trying to compensate after injury. This technology is forcing neighbouring cells around the area of damage in the visual cortex to turn on, taking over for the dying cells. Jamie Talan