Purpose: To assess the relationship of retinal vessel caliber with diabetes and diabetic retinopathy (DR).
Design: Population-based cross-sectional analysis of the Blue Mountains Eye Study, Australia (n = 3,654, age >or=49 years).
Methods: Diabetes was defined as physician-diagnosed or fasting blood glucose >or= 7.0 mmol/l; impaired fasting glucose as fasting glucose 6.1 to 6.9 mmol/l. DR was graded from retinal photographs. Retinal vessel caliber was measured from digitized images.
Results: After controlling for age, gender, blood pressure, and other factors, mean retinal venular caliber was significantly wider in participants with moderate-severe nonproliferative DR (severe 262.7 microm; moderate 236.7 microm) than in nondiabetic participants (221.9 microm) or participants with diabetes but no DR (221.2 microm) (P < .0001). Mean retinal arteriolar caliber was significantly wider in participants with diabetes (193.5 microm) than in nondiabetic participants (190.2 microm) (P < .01).
Conclusions: Increasing severity of DR in persons with diabetes is associated with widening of retinal venular caliber.