Prevalence and Associations of Enhanced Retinal Arteriolar Light Reflex: A New Look at an Old Sign

Abstract

To assess the prevalence, associated risk factors and prognosis (mortality) of the enhanced retinal arteriolar light reflex sign in an older Australian population. Population-based cross-sectional study. Three thousand six hundred fifty-four participants (82.4% response) ages >/=49 years from Australia's Blue Mountains region. Retinal photographs of participants were graded for presence and severity of the enhanced arteriolar light reflex sign by comparison with standard photographs. Associations with systemic factors (subject-specific) and ocular variables (eye-specific) were assessed by logistic regression. Mortality data were obtained using the Australian National Death Index. Hazard ratios were calculated using Cox regression. Prevalence of enhanced arteriolar light reflex and associations with demographic variables (age, gender), blood pressure, blood parameters, health risk behaviors, cataract, retinal vessel wall signs, retinopathy, and 10-year incident mortality. The enhanced arteriolar light reflex sign was found in 1053 participants (31.7%, including 28.8% graded as mild and 2.9% as marked). Prevalence decreased with age (36.0%, 37.7%, 28.0%, and 18.8% for age groups < 60, 60-69, 70-79 and > or = 80 years, respectively, P(trend)<0.0001); odds ratio (OR) 0.78; and 95% confidence interval (CI) 0.72 to 0.85 per decade. Persons with cataract were less likely to have mildly enhanced light reflex (OR, 0.74; CI 0.64-0.87). After multivariate adjustment, mildly enhanced light reflex was significantly associated with serum glucose (OR 1.11 per SD increase), total cholesterol (OR 1.11), low-density lipoprotein (OR 1.55), triglycerides (OR 1.11), platelets (OR 0.89), and body mass index (OR 1.12). Markedly enhanced light reflex was significantly associated with mean arterial blood pressure (OR 1.24), heavy alcohol consumption (OR 2.66, > or = 40 grams alcohol per day), and serum glucose (OR 1.16). Strong associations were demonstrated between presence of mildly enhanced light reflex and either arteriovenous nicking (OR 3.12) or retinopathy (OR 1.96). There was no association between mildly or markedly enhanced light reflex and either all-cause or vascular mortality. In this older population, the enhanced retinal arteriolar light reflex sign was a relatively common finding. Although some associations of this sign with vascular risk factors were found, only a marked level of enhanced light reflex was correlated with elevated blood pressure, but not with poor survival.