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

Abstract

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. 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. For right and left eyes, mean (SD) CRAE was 168.8 (16.0) μm and mean CRVE was 254.2 (25.2) μm. 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. 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.