Objective: Few studies have examined the effect of blood pressure (BP) on the retinal microvasculature in children. We examined the relationship between BP and retinal vessel caliber in a sample of preadolescent schoolchildren.
Methods: Eligible high school students [2353/3144 (response 75.3%); mean age, 12.7 years] from 21 randomly selected schools in Sydney, Australia, were examined during 2004-2005. Retinal vessel caliber was quantified from digital retinal images using well known computer-based programs. BP was measured using a standard protocol and high BP was defined according to published guidelines for this age group.
Results: After adjusting for age, sex, ethnicity, BMI, iris color, axial length, birth weight and the fellow retinal vascular caliber, children in the highest quartiles of SBP, DBP or mean arterial BP had approximately 5 mum narrower mean retinal arteriolar caliber than those in the lowest quartiles of all three BP measures (all P for trend <0.0001). Children classified as having high BP had approximately 2.0 mum narrower mean retinal arteriolar caliber than normotensive children (P = 0.002). In boys, each 10-mmHg increase in SBP was associated with a 2.19-mum increase in the mean retinal venular caliber (P = 0.0003), but no similar significant association was evident in girls.
Conclusion: Elevated BP is associated with narrower retinal arterioles in preadolescent boys and girls, and also with wider retinal venules in boys. These data provide further evidence of early microvascular changes associated with high BP in older children.