Abstract
Purpose: :
To evaluate the association between outdoor leisure activity and myopia in Singapore teenage children.
Methods: :
This cross-sectional study includes 1,144 teenagers aged 11-20 years old, 586 girls and 558 boys, attending the 2006 visit in the Singapore Cohort study Of the Risk factors for Myopia (SCORM). The participation rate = 1142/1570 = 72.74%. Refractive error was measured using the table-mounted autorefractor after cycloplegia using 3 drops of 1% cyclopentolate. Axial length, vitreous chamber depth, anterior chamber depth and lens thickness were measured using the A-scan ultrasound machine. The participants completed a questionnaire describing the average number of hours per day on outdoor leisure such as picnics, and playing out of doors in the backyard on weekdays and weekends. We also asked about the hours per day spent on different types of indoor and outdoor sports such as tennis or swimming.
Results: :
The mean amount of time in hours per day spent on outdoor leisure was 1.07, 1.42 for playing outdoors, and 0.80 on outdoor sports. In multiple logistic regression models with myopia as the outcome variable, the odds ratio for outdoor leisure for each hour per week was 0.85 [95% confidence interval (CI) 0.75, 0.98; p=0.02], after adjusting for age, gender, ethnicity, school, books read per week, height and parental myopia. However, playing outdoors, and outdoor sports were not significantly associated with myopia in multiple logistic regression models. In a multiple linear regression model, refractive error was significantly associated with outdoor leisure (regression coefficient = 0.28; 95% CI 0.12, 0.43), after adjustment for similar factors.
Conclusions: :
Outdoor leisure may be protective for myopia in Singapore teenage children.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • myopia • refractive error development