The relationship between myopia and near work, time outdoors and socioeconomic status in children and adolescents

Abstract

Background: To investigate environmental and social risk factors for myopia in children and adolescents in Germany.

Methods: 1437 children aged between 3 and 18 inclusive were examined as part of the LIFE Child study based in Leipzig, Germany. Information about leisure time activities and social status was ascertained by parents and children in a questionnaire. Refractive status was attained by measuring noncycloplegic autorefraction. Myopia was defined as spherical equivalent (SE) ≤ - 0.75 D. Risk factors were identified using multiple logistic regression analysis.

Results: In multiple logistic regression analysis, myopia was significantly associated with less frequent outdoor activity ("once a week" vs. "twice a week or more": odds ratio (OR) 4.35, 95% confidence interval (CI) 1.89-9.98, p<0.01) and longer near work sessions (1-2 h vs. < 1 h: OR 1.83, CI 1.10-3.04, p=0.02; > 3 h vs. < 1 h: OR 3.71, CI 1.43-9.61, p<0.01) after adjustment for age, sex and socioeconomic status (SES). Duration of outdoor activity, near work frequency and SES showed no significant association with myopia (p > 0.05). Children with a lower SES were involved in longer periods of outdoor and near work activities but on fewer occasions over the course of the week, although this connection was not significant.

Conclusion: Myopia is associated with environmental factors. The present findings suggest that daily exposure to sunlight and a restriction of long-duration near work activities might protect against pathological eye growth. Prevention strategies should be implemented for children at all ages.

Keywords: Children; Myopia; Near work; Refractive error; Socioeconomic status; Time outdoors.