Association of Retinal Vascular Diameter and Vascular Branching Angle with Diabetic Retinopathy Stage: A Cross-Sectional Study

Purpose: To determine the association between retinal vascular diameter and its branching angles with diabetic retinopathy (DR) stages in diabetic patients Methods: A descriptive analytic cross-sectional study was conducted in 62 diabetic patients (120 eyes) referred to Farabi Eye Hospital between June 2008 and December 2009. Digital fundus photography pictures were imported into Photoshop software and diameters of arterioles and venules at their second branches from the disc were calculated. Meanwhile branching angles were measured in the same arterioles and venules. DR was graded by retinal specialists according to Airlie House classification of DR. Retinal vascular diameters and their branching angles were compared in different DR stages. Results: There was a significant difference between retinal vascular diameters in different retinopathy stages. The diameter was significantly more in proliferative stage compared with mild nonproliferative stage (P<0.05). After multivariate analysis, age or hypertension has had no effect on the results. However, there was no significant difference between vascular angles in different retinopathy stages (P>0.05). Conclusion: Retinal vascular diameter, but not retinal vascular angle, seems to be related with retinopathy stage regardless of age and hypertention in these patients.