Abstract
Purpose :
Emmetropia has been reported as a predictor of myopia onset. But the distribution of myopiogenic factors among emmetropic children has not been well understood. This study aimed to investigate the factors for myopia among preschoolers and the associations with emmetropia.
Methods :
Since launch of the Yilan Myopia Prevention and Vision Improvement Program (YMVIP) in August 2014, we have promoted outdoor activities and conducted a countywide population-based, annual cross-sectional study in all kindergartens in Yilan County, Taiwan. Eye examinations, including cycloplegic autorefraction, have been provided for all preschoolers aged 5-6 years. Demographics, medical history, parental history, near work habits, screen time and outdoor activity was collected by questionnaire. Refractive status was determined according to the cycloplegic spherical equivalent (SE) of the eye with less SE and classified into myopia (SE ≤-0.5D), emmetropia (0.5D > SE >-0.5D), or hyperopia (SE ≥0.5 D).
Results :
Among 20,419 preschoolers from 2014 through 2019, a total of 18, 621 (9,715 [52.2%] boys) were finally included. Of those, 2,003 (10.8%), 5,057 (27.2%) and 11,561 (62.0%) were myopic, emmetropic and hyperopic. Most of association factors for myopia identified by multinomial logistic regression, including male (odds ratio [OR], 1.25; 95% CI, 1.13-1.37), caregiver myopia (OR, 1.76; 95% CI, 1.58-1.96), screen time ≥1 hour/weekday (OR, 1.20; 95% CI, 1.09-1.32), exposure to the YMVIP promoting outdoor activity (one-year exposure: OR, 0.80; 95% CI, 0.69-0.94; two-year exposure: OR, 0.46; 95% CI, 0.41-0.52), and higher education level of caregiver (OR, 0.79; 95% CI, 0.72-0.88), were also significantly associated with emmetropia (male [OR, 1.22; 95% CI, 1.14-1.30), caregiver myopia [OR, 1.42; 95% CI, 1.32-1.53], screen time ≥1 hour/weekday [OR, 1.15; 95% CI, 1.07-1.23], exposure to the YMVIP promoting outdoor activity [one-year exposure: OR, 0.84; 95% CI, 0.74-0.94; two-year exposure: OR, 0.62; 95% CI, 0.56-0.68], and higher education level of caregiver [OR, 0.87; 95% CI, 0.81-0.94]).
Conclusions :
Emmetropia and myopia share similar risk factors in a preschooler population and the associations of these myopiogenic factors with emmetropia are weaker than with myopia, which may indicate the tendency of emmetropia toward myopia among preschoolers.
This is a 2021 ARVO Annual Meeting abstract.