The role of retinal vessels caliber as a marker of vascular aging in large arteries

OBJECTIVE: To analyze the relationship between retinal vessel caliber and large arterial structure and function in a sample of the general population. METHODS: A cross-sectional study was conducted among 229 participants from the EVIDENT trial (mean age 55.6±12.1 years, 61.1% women). Retinal photographs were digitized, temporal vessels were measured in an area of 0.5 to 1 disc diameter from the optic disc and the arterio-venous ratio (AVR) was estimated. Vascular structure and function were assessed by evaluating carotid intima-media thickness (IMT), pulse wave velocity (PWV), augmentation index (AIx), ankle brachial index and ambulatory arterial stiffness index. RESULTS: The mean AVR was 0.792 ± 0.082, calculated from an arterial caliber of 109.1 ± 12.5 μm and a venous caliber of 138.7 ± 15.4 μm. A total of 13.1% of the patients presented vascular damage. The AVR was inversely correlated with carotid IMT (r = -0.190, P < 0.01), PWV (r = -0.178, P < 0.01) and AIx (r = -0.187, P < 0.01). In a multiple linear regression analysis, the associations with IMT and with AIx remained after adjusting for possible confounders (β = -0.152, P = 0.026; and β = -18.1, P = 0.037, respectively), but the association with PWV was lost when blood pressure was added (β = -1.520, P = 0.215). In a logistic regression analysis, the odds ratio of the first tertile of mean AVR (<0.76) of having a vascular injury was 7.09 (95% confidence interval 1.78-28.17, P = 0.011) after adjusting for possible confounders. CONCLUSION: In the general population, lower AVR values are associated with increases in carotid IMT, AIx and PWV. AVR may be a good predictor of asymptomatic vascular damage in large arteries.