Abstract
Purpose:
To assess the impact of factors related to migration and acculturation (country of birth, age at migration and language spoken at home) on refractive errors in the US.
Methods:
A total of 5365 adults (2083 Whites, 1464 Blacks, 1175 Hispanics and 643 Chinese) aged 45 to 84 years living in the U.S participated in the study. Information regarding acculturation level including country of birth, age at migration and language spoken at home were collected from interviews. Non-cycloplegic refraction was performed in both eyes of all participants using an autorefractor (NIDEK ARK-760 Autorefractor). Myopia was defined as spherical equivalent of -1.0 diopters (D) or less in the right eye while hyperopia was defined as SE of 1.0 D or more. Multivariate logistic regression model was used to estimate the association between the acculturation variables and myopia.
Results:
Participants born in the US were more likely to have myopia (odds ratio [OR]: 1.28; 95% confidence interval [CI]: 1.03, 1.61) and less likely to have hyperopia (OR: 0.70; 95% CI: 0.58, 0.85) than those born outside the US, while controlling for age, gender, race/ethnicity, education, cataract and height. Participants who spoke English at home had a higher prevalence of myopia (OR: 1.77; 95% CI: 1.36, 2.32) and a lower prevalence of hyperopia (OR: 0.67; 95% CI: 0.54, 0.84) compared with those who spoke a non-English language. For participants born outside the US, those who migrated to the US before the age of 20 had a higher prevalence of myopia (OR: 2.44; 95% CI: 1.69, 3.57) and a lower prevalence of hyperopia (OR: 0.62; 95% CI: 0.44, 0.86) compared with those who migrated after the age of 20. When stratified by race/ethnicity, the trends were similar among Chinese, Blacks and Hispanics with higher acculturation level in the US being associated with a higher prevalence of myopia. The association was not found in Whites due to the small numbers of White participants who were born outside the US (n=138) or who did not speak English at home (n=32).
Conclusions:
Myopia is more while hyperopia is less common among new immigrants with higher acculturation levels in the US. These findings suggest that country-specific environmental factors may affect the onset and progression of refractive errors in diverse populations.
Keywords: 605 myopia •
464 clinical (human) or epidemiologic studies: risk factor assessment •
463 clinical (human) or epidemiologic studies: prevalence/incidence