Mouse study links retina changes to dementia risk, eye exams may help

A study of mice published this month in Alzheimer's and Dementia suggests routine eye exams could one day help identify risk for Alzheimer's disease and related dementias years before cognitive symptoms appear. Researchers at The Jackson Laboratory in Maine report that animals carrying a common genetic variant showed abnormal changes in tiny retinal blood vessels that mirrored subtle vascular damage previously observed in the brain.

The team, led by neuroscientist Alaina Reagan, examined mice with the MTHFR677CT variant, a mutation present in up to 40 percent of people in some populations, and found twisted, narrowed and swollen retinal arteries and reduced vessel branching as early as six months of age. Those vascular patterns, the authors say, resemble changes linked to poor cerebral blood flow and heightened risk of cognitive decline. "If you're at an optometrist or ophthalmologist appointment, and they can see odd vascular changes in your retina, that could potentially represent something that is also happening in your brain," Reagan said.

The new paper builds on earlier work by the same group that documented fewer cortical vessels and reduced brain blood flow in mice with...