As people with diabetes age, they are more likely than those without the condition to develop cognitive disorders such as Alzheimer's Disease. Now, researchers from Joslin Diabetes Center in Boston have found that routine eye exams could help identify changes linked to cognitive decline in patients with type 1 diabetes.
"Since we knew that there were cellular changes in the retina that might reflect changes in the brain, we were interested to see whether imaging techniques that visualize those changes in the retina might be reflective of changes in cognitive functions," says Ward Fickweiler, lead author of the paper.
For the study, the researchers examined routine eye scans gathered from 129 patients with type 1 diabetes at Joslin's Beetham Eye Institute. While one set of scans was based on optical coherence tomography (OCT), a technique that uses light to gather cross-sections of the retina, another set of scans employed OCT angiography, an extension of OCT that also examines blood vessels in the retina.
Alongside these scans, participants also partook in a series of cognitive tests to examine memory function and psychomotor speed- the amount of time taken to arrange objects by hand.
In the end, the researchers found very strong links between memory task performance and structural changes in the deep blood vessel networks of the retina. The researchers also found an association between proliferative diabetic retinopathy (PDR), a complication from diabetes that seriously impacts eyesight, and psychomotor speed.
While larger trials are needed to confirm these results, the researchers are optimistic that their findings could pave the way for new ways to identify cognitive decline in those with diabetes- and ideally before onset too, when it is most treatable. This comes especially as current methods to test for Alzheimer's are difficult and expensive to conduct, and thus are typically used when people have already developed symptoms of cognitive decline, and not before.