Abstract
Purpose::
To determine the prevalence rates and risk factors for refractive error and distribution of biometry in a multi-racial elderly population in Singapore.
Methods::
A population-based prevalence survey, the Singapore Longitudinal Aging Study (SLAS), was conducted in residents aged 55 to 85 residing in five districts in South-Eastern Singapore. Refractive error was determined using a table-mounted autorefractor (Canon RK-F1; Tokyo, Japan) and biometry using the IOLMaster (Zeiss, Oberkochen, Germany).
Results::
From 3315 eligible people, 2413 (72.8%) were examined and 578 excluded from this analysis due to prior cataract surgery or inability to obtain a refraction. The prevalences of myopia (- SE < -0.5D), hyperopia (- SE > +1.0D), astigmatism (cylinder > -1.0D), and anisometropia (difference > 1.0D) were 30.1% (95% confidence interval [CI]: 28.0, 32.3), 41.5% (95%CI: 39.2, 43.8), 40.0% (95% CI: 37.7, 42.2), and 21.0% (95% CI: 19.1, 23.0), respectively. The prevalence of myopia varied significantly with race: Chinese 30.8%, Indians 22.6% and Malays 18.2% (p=0.04). The prevalences of myopia, astigmatism and anisometropia were significantly higher for males compared to females while the reverse was true for hyperopia (all p<0.05). The age pattern of myopia was bimodal, while the prevalences of both astigmatism and anisometropia increased with age. The axial length and anterior chamber depths decreased with age (p’s < 0.001). Males and those with higher educational levels had higher rates of myopia in multivariate analyses. Hypertension tended to be more hyperopic, but this relationship was of borderline significance on multivariate analysis (OR 1.2 (95% CI, 0.99, 1.5)).
Conclusions::
The prevalence of myopia is high in elderly Singaporeans and the rates are higher in males and Chinese. The possible link between hypertension and hyperopia needs further investigation.
Keywords: refraction • clinical (human) or epidemiologic studies: prevalence/incidence • aging