Abstract
Purpose :
There is evidence that myopia prevalence is increasing worldwide, which has spurred discussion on interventions. A recent meta-analysis found an association between time spent outdoors and myopia in children. Through a cross-sectional study, we aimed to examine whether living near an open recreation area (ORA), a proxy for outdoor activities, would be associated with lower myopia rates among preschoolers.
Methods :
We conducted a retrospective analysis using anonymized data collected between 2012 and 2017 on children who failed the screening and then underwent cycloplegic refraction (CR) performed by the UCLA Preschool Vision Program. Inclusion criteria was age at screening between 36 to 71 months and having a record of CR. The outcome of interest was myopia in at least one eye, defined as spherical equivalent measured by CR of -1.00 D or worse. The predictor of interest was proximity to an ORA, and a child’s school address was used as a proxy for a child’s residence. Using Geographic Information System (GIS) analysis, minimum distance by a straight line from school to the nearest ORA was calculated for each child and analyzed as greater or less than 0.5 miles. Logistic regression models were performed to evaluate the association between myopia and proximity to an ORA, and adjusted for potential confounders, including age, gender and race.
Results :
7,227 children met the inclusion criteria. Among them, 1,018 (13.9%) had myopia. There were 6,316 (87.4%) who lived 0.5 miles or less from an ORA. In unadjusted analysis, children who lived more than 0.5 miles from an ORA had a slightly higher odds of myopia compared to those who lived 0.5 miles or less (OR: 1.07, 95% CI: 0.88, 1.30, P=0.53). After adjusting for confounders, the association stayed similar (OR: 1.04, 95% CI: 0.85, 1.28, P=0.67).
Conclusions :
Our results did not show a significant association between myopia prevalence and ORA proximity. One limitation was the use of school address as a proxy for child’s residence. Another limitation was that screening protocol utilizes non-cycloplegic autorefraction with a myopic cut off of -3.25 D or more, so myopia status might not be accurate. Future studies addressing these limitations may reveal more insights. Despite of the findings, GIS analysis could be valuable in examining relationships between vision problems and geographic factors, which might have big public policy implications.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.