Eye imaging may reveal cognitive dysfunction risk in type 1 diabetes
Noninvasive scans of retinal thickness and vasculature may be used in risk assessment for cognitive dysfunction for adults with type 1 diabetes, according to study data.
“Currently, methods for detecting cognitive disorders, such as MRI and PET scans, are time-consuming, not widely available and expensive,” Ward Fickweiler, MD, a research fellow in the department of ophthalmology at Harvard Medical School, and George L. King, MD, a professor of medicine and ophthalmology at Harvard Medical School and chief scientific officer at Joslin Diabetes Center, told Healio. “Routine eye exams, such as OCT and OCT angiography, can be easily performed within minutes without patient discomfort and are widely available in U.S. ophthalmic clinics.”
Fickweiler, King and colleagues conducted an exploratory, cross-sectional study of a subset of individuals with 50 or more years of insulin-dependent diabetes (Joslin 50-Year Medalist Study) who completed cognitive testing and advanced retinal imaging. Retinal imaging consisted of OCT and OCT angiography scans to analyze neural retinal layer thickness and vascular density for superficial and deep retinal capillary plexus. The findings were published in The Journal of Clinical Endocrinology & Metabolism
In OCT angiography findings, decreased vascular density of the superficial plexus was associated with decreased psychomotor speed (point estimate, – 0.03; 95% CI, –0.06 to – 0.01; P = .01), whereas decreased vessel density of the deep retinal capillary plexus was associated with worse delayed memory (point estimate, 0.08; 95% CI, 0.03-0.14; P = .002).
In OCT findings, thinning of the outer nuclear layer of the neural retina was associated with worse performance in psychomotor speed in the nondominant (point estimate, –0.04; 95% CI, –0.07 to –0.01; P = .01) and dominant hand (point estimate, –0.08; 95% CI, –0.16 to 0.01; P = .05), as well as declines in immediate memory (point estimate, 0.72; 95% CI, –0.02 to 1.45; P = .05). Thinning of the outer plexiform layer was associated with worse delayed memory score (point estimate, –0.45; 95% CI, –0.87 to –0.03; P = .04).
When the combined effects of OCT angiography and OCT were analyzed, psychomotor speed was more than 20% lower in the lowest tertile of vascular density for superficial retinal capillary plexus and outer nuclear layer thickness compared with the highest, and delayed memory score was more than 30% lower in the lowest tertile of vascular density for deep retinal capillary plexus and outer plexiform layer thickness compared with the highest tertile of deep retinal capillary plexus of the retinal microvasculature.
Fickweiler and King said a future study will be conducted with a larger population that will also include analysis of the brain.
“We plan to perform a larger prospective study to confirm the potential of eye imaging studies to identify signs of cognitive decline over time,” Fickweiler and King said. “This research will include people with type 1 diabetes who are younger and haven’t had the disease for as long as the Medalists. We also will analyze MRI brain images and postmortem brain samples donated by Medalists. Additionally, we will be characterizing clinical changes that can provide clues as to the common mechanisms which may inflict damage on brain and retina tissues in diabetes.”
For more information:
Ward Fickweiler, MD, can be reached at email@example.com.
George L. King, MD, can be reached at firstname.lastname@example.org.