More Evidence Linking Impaired Vision and Dementia Risk

Why would vision impairment correlate with risk of dementia? The retina is an extension of the central nervous system, so one might think that similar processes of aging and neurodegeneration contribute to both loss of visual capacity and loss of cognitive capacity. But it might also be the case that in the brain, as for muscles, there is a degree of "use it or lose it" taking place over the course of later life. Without stimuli, in other words, the aging brain declines more rapidly. Most of the evidence for an association between visual impairment and cognitive impairment in older individuals doesn't allow us to determine which of these options is the dominant mechanism, however. Recently, researchers found that one can look at people who did or did not have cataract surgery in order to infer the effects of visual impairment on cognitive function. Mechanisms driving cataract formation should have little in common with mechanisms driving cognitive impairment. Researchers found that cataract induced visual impairment does correlate with cognitive impairment, and removal of cataracts prevents this later loss of cognitive function. This provides strong support for the role of visual stimuli in slowing the pace of brain aging. Study shows dementia more common in older adults with vision issues In a sample of nearly 3,000 older adults who took vision tests and cognitive tests during home visits, the risk of dementia was much higher among those with eyesight...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs