Arteriole tortuosity is an important sign of retinal disease which is associated with diabetic retinopathy, but it is unclear how arteriole tortuosity changes over time in populations with diabetes. It has been suggested that retinal vasculature geometry changes precede diabetic retinopathy. Here, we evaluate whether arteriole tortuosity changes precede diabetic retinopathy by examining arteriole tortuosity and retinopathy at two points in time four years apart.

A population of 126 subjects had retinal photographs at baseline and approximately four years later (48 ± 9 months) in a telehealth screening program. The photographs from both eyes at baseline and follow up were graded for tortuosity (straight, wavy, or tortuous) and retinopathy using clinical ETDRS guidelines. Consensus grades (across graders) were used, but when consensus was not reached or the image quality was too poor to grade, the subject was removed from analysis. Other health markers, such as duration of diabetes, hemoglobin A1c (HbA1c), neuropathy status, and insulin usage, were also recorded. Differences in time points were assessed with paired t-tests.

Of the 109 subjects (218 eyes) included in final analysis, 24 eyes had retinopathy at baseline and 26 eyes had retinopathy at follow up, which was almost all mild (93%). Tortuosity was largely unchanged at follow up (76%) and on average was straight or wavy. Nine eyes had decreased tortuosity (4.3%). The final 19.7% had arteriole tortuosity which increased a level from baseline. The subjects with increased tortuosity had a shorter duration of diabetes at baseline (5.8 years vs 7.4 years, p<0.04). There was no relationship between retinopathy development and arteriole tortuosity increasing or between HbA1c and change in tortuosity.

It appears that retinal arteriole tortuosity may increase most over early years of diabetes development and then stabilize. Therefore, it may be more valuable to monitor retinal arteriole tortuosity in early years of diagnosis in both clinical and telemedicine settings. More research is needed following changes in tortuosity over time in patients with diabetes.