Outdoor Jogging and Myopia Progression in School Children From Rural Beijing: The Beijing Children Eye Study

Abstract

Purpose To assess the influence of an outdoor program on myopia progression in school children. Methods The prospective interventional school-based study included 373 students aged 6 to 7 years (grade 1 or 2) who were examined annually between 2012 and 2016. Between 2012 and 2013, the children in the study group ( n = 157) performed a 30-minute jogging exercise every school day, while the children in the control school ( n = 216) did not. All children underwent a comprehensive ocular examination, including biometry. Results At 1 year after baseline, axial elongation and progression of myopic refractive error were significantly lower in the study group than in the control group. Study group and control group differed in axial elongation only in the subgroup of children nonmyopic at baseline, while axial elongation in the children myopic at baseline did not differ between both groups. At 1 and 2 years after the outdoor program stopped, increase in axial length was significantly larger in the study group. At 4 years after baseline, study group and control group did not differ significantly in total axial elongation and total change in refractive error. Conclusions An outdoor program of 30 minutes performed every school day for 1 year temporarily reduced myopia progression in schoolchildren nonmyopic at baseline, with a complete rebound effect after the program ended within the 3 following years. Translational Relevance An outdoor program of 30 minutes performed every school day for 1 year temporarily reduced the progression of myopia in schoolchildren nonmyopic at baseline for the period when the program was carried out.

Refractive error, axial length, environmental and hereditary factors associated with myopia in Swedish children

“…AL findings are consistent with results from cross-sectional and cohort studies on myopia and outdoor time. [58][59][60][61][62] It is unclear what underlying mechanism is responsible for the protective effect of outdoors on limiting eye growth. One possible mechanism is the release of retinal dopamine stimulated by high light levels.…”

Associations Between Screen Exposure in Early Life and Myopia amongst Chinese Preschoolers

“…Moreover, the human eye generally undergoes a rapid growth from birth to 3 years of age and the variability of refractive error decreases progressively during this period [47], and the greatest increase in eye growth, which is measured by axial length, occurs during the first 10 months of life [48]. Therefore it is speculated that the steady fixation at a specific distance might contribute to myopia for very young children's eyes, and one reason that outdoor activities appear to be beneficial [49][50][51][52] might be that they encourage more frequent shifts of attention and focus. If sufficiently confirmed in further studies, the speculation could provide insight into the mechanism of myopia.…”

“…If sufficiently confirmed in further studies, the speculation could provide insight into the mechanism of myopia. Second, a series of studies consistently showed that children who spent more time outdoors were significantly and negatively associated with incident myopia [49][50][51][52], and low illuminance levels indoors can cause myopia in animal models [53]. More time spent indoors watching electronic screens could translate into less time spent outdoors and insufficient exposure to natural light, and thus increase the risk of preschool myopia.…”

IMI Prevention of Myopia and Its Progression

“…However, a recent study revealed a potential rebound effect that occurred within three years after stopping of a one-year program with 30 minutes of daily outdoor jogging. 24 Including only children who were myopic at baseline of the study, the intervention was associated with a slight increase in myopia progression.…”