- People who show signs of retinal blood vessel damage at age 60 could be more likely to develop thinking and memory problems.
- People who had moderate to severe retinopathy were more likely to have greater drops in their memory and thinking test associated scores over time than the people who had healthy eyes.
- Blood vessels in the eye and the brain are similar to each other anatomically.
People who had experienced retinal blood vessel damage (retinopathies) at age 60 could be more likely to develop thinking and memory problems by the time they are 80 than people with healthy eyes, finds a new study. The findings of this study are published in the Journal of American Academy of Neurology.
"Problems with the small blood vessels in the brain are likely as important a factor in cognitive decline as problems with larger arteries, but we don't have the ability to take pictures of these small vessels with brain imaging," said study author Jennifer A. Deal, PhD, of Johns Hopkins University in Baltimore, Md. "Because the blood vessels in the eye and the brain are so similar anatomically, we hypothesized that looking at the blood vessels in the eye would help us understand what was happening in the brain."
The study involved 12,317 people who took tests of memory and thinking skills at the beginning of the study, again about six years later and for the third time about 20 years after the first test. A special retinal camera was used to take photos of the back of the participants' eyes about three years after the start of the study when the participants were an average age of 60.
The researchers found that people who had moderate to severe retinopathy were more likely to have bigger drops in their scores on the memory and thinking tests over time than the people who had healthy eyes.
For the people with moderate to severe damage, their average scores on the tests declined by 1.22 standard deviation units over 20 years, compared to a decline of 0.91 standard deviation units for people with healthy eyes. When researchers adjusted to take into account people who had missed some of the thinking tests, they found that the difference between the two groups was equal to 0.57 standard deviation units.
"To put this in perspective, a previous study using the same methods found that the effect of diabetes on cognitive decline was equal to 0.21 standard deviation units," Deal said. "If our study results can be confirmed, differences in retinal integrity could provide reasonable estimates of how much small blood vessel damage in the brain is contributing to cognitive decline."