Interplay of Genetic and Environmental Factors in Myopia Progression among Elementary School Children in Jeju Island, South Korea: A Prospective Cohort Study

Myopia has become a significant global health concern, particularly in East Asian countries. This prospective cohort study investigated the complex interplay of genetic and environmental factors in myopia progression among 425 elementary school students in Jeju Island, South Korea, over a two-year period. Ocular biometric parameters and lifestyle factors were assessed using a non-contact optical biometer and questionnaires, respectively. The study revealed that the proportion of participants using smartphones for 4 hours or more increased from 0.2% at baseline to 10.6% at the 2-year follow-up. Additionally, the mean axial length increased by 0.43 mm, and the mean emmetropic power showed a myopic shift of 1.2 D over the study period. Interestingly, the change in axial length and emmetropic power over the 2-year period showed significant correlations with time spent on after-school homework and learning, but not with parental myopia. While genetic factors, particularly parental myopia, play a role in the development of myopia, environmental factors such as extensive after-school learning may have a more significant impact on myopia progression. The findings emphasize the need for balanced lifestyles, outdoor activities, and management of near work and screen time to prevent and control myopia in school-aged children. The study has important implications for public health, education, policy development, and future research, as implementing evidence-based strategies and exploring innovative approaches can help reduce the burden of myopia and improve the visual health of future generations.