A new study from Georgia Tech shows that when patients with macular degeneration focus on using another part of their retina to compensate for their loss of central vision, their brain seems to compensate by reorganizing its neural connections.
Age-related macular degeneration is the leading cause of blindness in the elderly. The study appears in the December edition of the journal Restorative Neurology and Neuroscience .
"Our results show that the patient's behavior may be critical to get the brain to reorganize in response to disease," said Eric Schumacher, assistant professor in Georgia Tech's School of Psychology. "It's not enough to lose input to a brain region for that region to reorganize; the change in the patient's behavior also matters."
In this case, that change of behavior comes when patients with macular degeneration, a disease in which damage to the retina causes patients to lose their vision in the center of their visual field, make up for this loss by focusing with other parts of their visual field.
Previous research in this area showed conflicting results. Some studies suggested that the primary visual cortex, the first part of the cortex to receive visual information from the eyes, reorganizes itself, but other studies suggested that this didn't occur. Schumacher and his graduate student, Keith Main, worked with researchers from the Georgia Tech/Emory Wallace H. Coulter Department of Biomedical Engineering and the Emory Eye Center. They tested whether the patients' use of other areas outside their central visual field, known as preferred retinal locations, to compensate for their damaged retinas drives, or is related to, this reorganization in the visual cortex.