Long-term arterial retinal changes could indicate type 1 diabetes-related cognitive impairment, a recent study found. Participants of the Pittsburgh Epidemiology of Diabetes Complications Study received ≥3 fundus photographs between baseline (1986–1988) and time of cognitive assessment (2010–2015: n=119; 52% male; mean age and type 1 diabetes duration, 43 and 34 years, respectively). Central retinal arteriolar equivalent and central retinal venular equivalent were estimated via computer-based methods; overall magnitude and speed of narrowing were quantified as cumulative average and slope, respectively. Researchers found:

• Compared with participants without cognitive impairment, those with clinically relevant cognitive impairment experienced 1.8% greater and 31.1% faster central retinal arteriolar equivalent narrowing during prior years (t = −2.93 and t = −3.97, respectively).
• Interactions with HbA1c, proliferative retinopathy and white matter hyperintensities were not significant.
• No associations were found between central retinal arteriolar equivalent at baseline, at time of cognitive testing, or any central retinal venular equivalent measures, and cognitive impairment.