Abstract
Abstract: :
Purpose:. To determine if there is a measurable effect from regular use of aspirin on retinal microvascular abnormalities. Methods: Retinal photographs taken at baseline in the Blue Mountains Eye Study (1992–4, n=3654, aged 49+) were assessed by masked graders for focal arteriolar narrowing, arterio–venous nicking, and presence of retinopathy lesions (microaneurysms, retinal haemorrhages) in subjects without diabetes (n=2975). A computer– assisted method was used to measure average retinal arteriolar and venular diameters (n=2988), summarized as central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE) and arteriole to venule ratio (AVR). Frequency of aspirin use was obtained using questionnaire and structured interview, as were self–reported history of stroke, hypertension, ischaemic heart disease and smoking status. Height, weight, systolic and diastolic blood pressure were measured at baseline. Regular use of aspirin was defined if usage frequency was weekly or daily. Results: 775 persons (21.2%) reported regular use of aspirin and 361 users (46.6%) were men (P=0.05). The mean age of regular users and non–regular users was 68.5 ± 9.4 yrs and 65.3 ± 9.7 yrs, respectively (P<0.0001). Corresponding mean arterial blood pressure for the two groups was 105.2 ± 12.7 mmHg and 104.2 ± 12.2 mmHg, respectively (P=0.05). After adjusting for age, sex, mean arterial blood pressure, history of hypertension and smoking, the mean CRAE was 2.05 microns wider in regular aspirin users than in non–regular users (95% CI 0.36, 3.73, p=0.02). Adjusted mean CRVE was 1.24 microns wider in regular users – however this difference was not significant (CI –0.49, 2.98, p=0.16). Mean AVR did not differ between the two groups (0.86 in both groups, p=0.37). No significant association was found between regular aspirin use and the presence or severity of focal arteriolar narrowing, AV nicking or retinopathy lesions. Conclusions: In this older population, we detected a slightly wider retinal arteriolar diameter in regular aspirin users, controlling for age and blood pressure. Our findings suggest that aspirin may have beneficial effects at the microcirculatory level in addition to its well known anti–platelet effects.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: risk factor assessment • retina