Abstract
Purpose:
To determine the prevalence and risk factors for refractive errors and ocular biometry in Singapore adults aged over 40 years of Chinese, Indian and Malay origin.
Methods:
The Singapore Epidemiology of Eye Diseases (SEED) population-based prevalence survey (n=10033) comprises 3353 Chinese (SCES), 3400 Indians (SINDI) and 3280 Malays (SIMES). Refractive error was determined by subjective refraction, ocular biometric parameters including axial length (AL) by partial coherence interferometry (IOLMaster, Zeiss) and education and life style by questionnaire. Myopia and high myopia were defined as spherical equivalent (SE) of less than -0.5 Diopters (D) and -5.0 D, respectively, hyperopia as SE of less than 0.5 D and astigmatism defined as cylinder less than -0.5 D.
Results:
8772 subjects remained after excluding subjects with cataract surgery. The age and ethnicity-standardized prevalence of myopia, high myopia, hyperopia and astigmatism in Singapore adults over 40 years were 38.9 % (95% CI 37.1, 40.6), 8.4 % (95% CI 8.0, 8.9), 31.5 % (95% 30.5, 32.5) and 58.8 % (95% CI 57.8, 59.9), respectively. The age and ethnicity-standardized mean AL was 23.88 mm (95% CI 23.85, 23.90). After adjusting for age and gender, Chinese had higher odds ratios of 2.04 (p<0.001) for myopia, 3.28 (p<0.001) for astigmatism and longer ALs (0.43 mm longer, P <0.001) compared with non-Chinese. In a multivariate logistic regression model adjusted for age, gender, race, cataract, education and smoking, the OR of myopia was 4.7 (95% CI 3.7, 5.9; p<0.001) for those with university education compared with no education, 3.1 (95% CI 2.6, 3.7) for those with nuclear cataract compared with non-nuclear cataract, and 0.82 (95% 0.72, 0.94) for ever smoked vs never smoked. The population attributable risk was 38.6%, 18.9%, and 22.4% for education in Chinese, Malays and Indians.
Conclusions:
The prevalence of myopia and high myopia are high in Singapore adults and higher than other Asian countries such as India or European-derived populations. Besides nuclear cataract, education is a major risk factor for myopia while smokers are less likely to be myopic. However, the rates are lower compared with the younger “myopia” generation in Singapore with myopia prevalence rates of 83%. Chinese had the highest prevalence of myopia, high myopia, astigmatism as well as the longest AL compared with non-Chinese in Singapore.
Keywords: 605 myopia •
676 refraction •
463 clinical (human) or epidemiologic studies: prevalence/incidence