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Time spent outdoors can prevent the development of myopia
Author(s) -
ROSE KA
Publication year - 2008
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2008.5116.x
Subject(s) - refractive error , confidence interval , medicine , outdoor activity , odds ratio , demography , optometry , ethnic group , eye disease , ophthalmology , physical activity , physical therapy , pathology , sociology , anthropology
Purpose To examine the relationship between the development of myopic refractive error and near‐work and time spent outdoors. Methods The Sydney Myopia Study is a school‐based study using a random cluster design stratified by socio‐economic status. Over 4,000 Australian school‐aged children from two age groups had a comprehensive eye examination including cycloplegic autorefraction. Parents and students completed questionnaires on relevant lifestyle factors. Myopia was defined as spherical equivalent ≤‐0.5D in at least one eye. 1,765 children with a mean age of 6.7 years (75.3% response rate) and 2367 with a mean age of 12.7 years (75.3% response rate). Results There were no consistent associations between refraction and measures of activity in the 6 year‐old sample, where the myopia prevalence was 1.3%. It was significantly higher in the 12 year old sample at 12.7%. In this age sample, higher levels of outdoor activity (sport and leisure activities) were associated with more hyperopic refractions and lower myopia prevalence. Students who combined low levels of near‐work with high levels of outdoor activity had the most hyperopic mean refraction (+0.56D; CI 0.38‐0.75), while those who performed high levels of near‐work but had low levels of outdoor activity, had the least hyperopic mean refraction (+0.27D; 95% confidence interval, CI, 0.02‐0.52). The lowest odds ratios for myopia, after adjusting for near‐work, parental myopia and ethnicity, were found in groups performing the highest levels of outdoor activity. There were no associations between indoor sport and myopia. Conclusion Increasing time spent outdoors was associated a lower prevalence of myopia in the 12 year‐old sample. This may form the basis of a public health approach to the prevention of myopia.