Abstract
Purpose:
In most studies, myopia is related to higher education and higher socioeconomic class.<br /> We examined the relationship between factors of social economic status (SES)and risk of myopia in young children in the multi-ethnic, urban city of Rotterdam, the Netherlands.
Methods:
This study was part of the population-based birth-cohort study Generation R, in which 4,903 children with mean age 6.13 (SD ±0.46) participated in an extensive ophthalmologic examination. Presenting visual acuity was measured using LEA charts. Children with a monocular LogMAR visual acuity of >0.1 were referred to an ophthalmologist for automated cycloplegic refraction and a complete eye exam; medical records of these children and of those who were already receiving ophthalmological care were evaluated. Myopia was defined as spherical equivalent (SE) of ≤-0.5D in at least one eye. Risk of myopia was calculated using logistic regression analysis for ethnicity, monthly income, educational level of the mother, and city district. Associations were: 1) adjusted only for age, gender and anthropometry, and 2) additionally for lifestyle factors including indoor- and outdoor activity and serum vitamin D levels, and for birth parameters.
Results:
The prevalence of myopia was 2.4% (n=116). Children of African (OR 3.43, 95% CI 2.68 - 4.39), South- and East Mediterranean (OR 2.34, 95% CI 1.79 - 3.07), or Asian (OR 2.81, 95% CI 2.07 - 3.83) descent had a higher risk of myopia than children with a Northern European background. Children from low income families (OR 2.70 95% CI 2.22 - 3.29), with a mother who had only lower or secondary education (OR 2.21, 95% CI 1.81 - 2.71), and living in densely populated city districts had a higher risk of myopia (OR 1.88 95% CI 1.13 - 3.13). The associations lost statistical significance after adjustment for lifestyle factors.
Conclusions:
In contrast to many other studies, this study from Rotterdam found that that children with a lower socio-economic class and African ethnicity were more likely to develop myopia. Lifestyle factors appear to be an important explanation for these relationships, and may be more important than education or ethnicity per se.