Abstract
Purpose: :
We aimed to assess cross–sectional associations between use of different types of antihypertensive medication and presence of retinal vascular signs in an older population.
Methods: :
The Blue Mountains Eye Study examined 3654 participants aged 49+ years during 1992–4. Retinal photographs were graded for focal arteriolar narrowing, arteriovenous (AV) nicking and, in persons without diabetes, for vascular retinopathy lesions (microaneurysms, haemorrhages). Digitised retinal photographs were used to measure retinal arteriolar and venular diameters. Associations between antihypertensive medication subgroups and retinal vascular changes were assessed after adjusting for age, gender, presence of cardiovascular disease, diabetes and either mean arterial blood pressure (Model 1) or presence of hypertension (Model 2).
Results: :
Of 3583 participants with retinal photographs taken in at least one eye, 1469 participants (41%) were using antihypertensive medications at baseline. In both models, participants who were on diuretics in combination with any other antihypertensives were less likely to have focal arteriolar narrowing (adjusted odds ratio, OR 0.7, 95% confidence interval, CI, 0.4–1.0 Model 1; OR 0.4, CI 0.3–0.7 Model 2). Participants using calcium channel blockers in combination with any other antihypertensives were more likely to have AV nicking (OR 1.3, CI 1.0 –1.7 Model 1), particularly those using calcium channel blockers in combination with diuretics (OR 1.6, CI 1.1–2.5). In Model 2, the significant association between calcium channel blockers and AV nicking remained only in subjects who were not using aspirin. Subjects who were on beta–blockers in combination with diuretics were less likely to have AV nicking (OR 0.6, CI 0.4–0.9). In Model 1, all subtypes of antihypertensive medication were associated with a higher likelihood of having vascular retinopathy lesions. In Model 2 this association became non–significant, except among those using calcium channel blockers in combination with diuretics (OR 1.8, CI 1.0– 3.1). No significant associations were found between use of any type of antihypertensive medication and retinal arteriolar or venular diameters.
Conclusions: :
Our findings suggest a possible increased likelihood of AV nicking and vascular retinopathy lesions among calcium channel blocker users and a possible reduced likelihood of focal arteriolar narrowing among diuretics users. Further studies will be useful to explore whether any antihypertensive subgroups are associated with lower prevalence of microvascular signs.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • retina