Does education explain ethnic differences in myopia prevalence? A population-based study of young adult males in Singapore.

PURPOSE: To study interethnic variation in myopia prevalence and severity in young adult males in Singapore and to determine whether these variations are related to differences in education level. METHODS: A population-based survey of refractive errors in a cohort of 15,095 military conscripts between July 1996 and June 1997 using noncycloplegic autorefraction and a standard questionnaire. Prevalence rates of myopia (<-0.5 D) and severe myopia (<-6.0 D) were determined for Chinese, Malay, and Indian men; prevalence rate ratios were compared after adjusting for education level. RESULTS: Singapore has one of the highest prevalences of myopia (79.3%) and severe myopia (13.1%), with Chinese having higher rates (82.2%, 95% confidence interval 81.5, 82.9) compared with Indians (68.7%, 95% confidence interval 65.1, 67.1) and Malays (65.0%, 95% confidence interval 62.9, 67.1). Education was strongly associated with prevalence and severity of myopia. However, significant interethnic variation persisted after adjusting for education. CONCLUSIONS: There is a high prevalence of myopia in Singapore. Although prevalence and severity of myopia were strongly associated with education, interethnic variation observed was not fully explained by differences in education level.