Age- and Hypertension-Dependent Changes in Retinal Vessel Diameter and Wall Thickness: An Optical Coherence Tomography Study

PurposeTo validate and evaluate the reliability of retinal vessel diameter measurements by optical coherence tomography (OCT). The effects of age and hypertension on vessel diameter were also examined.DesignProspective, cross-sectional study.MethodsTwo hundred thirty-eight eyes (238 subjects) with no ocular disease were included. Hypertension was present in 106 subjects and absent in 132 subjects. Spectralis HRA+OCT was used to scan a circular region around the optic disc. Outer and inner diameters of the 4 largest retinal arteries and veins were measured using OCT vascular wall reflections, and vessel wall thickness was calculated.ResultsIntervisit, interexaminer, and interevaluator intraclass correlation coefficients of randomly selected vessel measurements were all greater than 0.90. Mean inner arterial and venous diameters were 87.8 ± 9.4 μm and 113.7 ± 12.5 μm, respectively. The OCT-measured mean inner arterial and venous diameters were significantly correlated to fundus photography caliber measurements (P = .005 and P = .001, respectively). Arterial and venous wall thicknesses were 17.4 ± 2.4 μm and 13.7 ± 2.1 μm, respectively, both of which were highly correlated with subject age (arterial: r = 0.612, P < .001, venous: r = 0.455, P < .001). Additionally, both mean arterial and venous wall thicknesses were significantly greater in subjects with hypertension than in age-matched subjects without hypertension (P = .020 and P = .015, respectively).ConclusionsRetinal vessel diameter measurements obtained with OCT were highly reproducible and vessel wall thicknesses, calculated using outer and inner diameter measurements, were significantly thickened by both aging and systemic hypertension.