Inter-lesion Relationships with Retinal Vascular Signs: The Blue Mountains Eye Study

Abstract

Abstract: : Purpose: To explore inter-lesion relationships among retinal vascular signs, including focal and generalized retinal arteriolar narrowing, arteriovenous (A/V) nicking and retinopathy lesions. Methods: Blue Mountains Eye Study participants (3654, aged 49+ years) were examined during 1992-4 and after 5 years. Baseline retinal slides were assessed for focal arteriolar narrowing and arteriovenous (A/V) nicking in all subjects, and for retinopathy lesions in non-diabetic subjects. Retinal vessel diameters were measured from retinal images of right eyes. Estimates of central retinal arteriolar equivalent (CRAE), representing average arteriolar diameter and arteriole-to-venule ratio (AVR), were calculated. Narrowest quintiles of CRAE and AVR indicated generalized arteriolar narrowing. Potential risk factors assessed included age, sex, systolic blood pressure (BP), body mass index (BMI), smoking, fasting blood glucose, serum lipids and fibrinogen. Independent predictive values of these signs for cerebro- or cardio-vascular events were assessed in Cox regression models including all signs, in addition to vascular risk factors. Results: Focal retinal arteriolar narrowing was found in 7.6 % and moderate to severe A/V nicking in 8.8 % of the population. Retinopathy lesions were detected in 11.3 % of non-diabetic subjects. Two signs were present in 1.5 –2.5 % and 3 signs in 0.5%. After adjusting for risk factors, systolic blood pressure was strongly associated with each sign. Age was associated with all signs except AVR. Both increasing BMI and serum triglyceride level were associated with A/V nicking and lower AVR. Current smoking was positively associated with both CRAE and A/V nicking but negatively with AVR. Neither fasting serum cholesterol nor HDL cholesterol were associated with any retinal vascular signs. Simultaneous adjustment for other retinal vascular lesions in the same Cox regression model did not affect the utility of each lesion in predicting vascular events in this population. Conclusions: Our findings suggest that both generalized and focal arteriolar narrowing appear to be specifically related to age and BP. Retinopathy lesions in persons without diabetes have similar associations. A/V nicking appears related to other cardiovascular risk factors, in addition to age and BP.

Keywords: clinical (human) or epidemiologic studies: ris • clinical (human) or epidemiologic studies: out • retina