Retinal Venular Diameter as an Early Indicator of Progression to Proliferative Diabetic Retinopathy With and Without High-Risk Characteristics in African Americans With Type 1 Diabetes Mellitus

Objective: To examine the relationship between retinal arteriolar and venular diameter and the 6-year progression of diabetic retinopathy (DR) in African Americans with type 1 insulin-dependent diabetes mellitus. Methods: Included were 468 African Americans with type 1 diabetes mellitus who participated in the New Jersey 725 and who had undergone a 6-year follow-up examination. Seven standard field retinal photographs were obtained at both examinations. Computer-assisted grading, from digitized images of field 1 of baseline retinal photographs, was accomplished to determine the average diameter of retinal arterioles (central retinal arteriolar equivalent [CRAE]) and venules (central retinal venular equivalent [CRVE]). Retinal vessel diameter was examined in relation to the 6-year incidence and/or progression of DR. Results: For right and left eyes, mean (SD) CRAE was 168.8 (16.0) mu m and mean CRVE was 254.2 (25.2) mu m. Both CRAE and CRVE were correlated between eyes (P < .001). Multivariate analysis with generalized estimating equations showed that larger CRVE in either the right or left eye was significantly associated with 6-year progression to either proliferative DR (PDR) or PDR with high-risk characteristics after adjusting for baseline clinical risk factors. Notably, a significant association between baseline CRVE and progression to PDR was present for eyes with no to moderate nonproliferative DR and also between baseline CRVE and progression to PDR with high-risk characteristics for eyes with no or nonproliferative DR. Conclusion: Larger retinal venular diameter is an independent and early indicator of progression to either PDR or PDR with high-risk characteristics in African Americans with type 1 diabetes mellitus.