关键词: 学龄前儿童, 近视前期

Abstract:  Objective Investigate the prevalence, related factors, and ocular characteristics of pre-myopia in preschool children aged 3 to 6 years, providing a theoretical basis for the prevention and control of myopia in Chinese children and adolescents. Design Cross-sectional study. Participants A total of 1473 preschool children from kindergartens in Tongzhou District, Beijing, were recruited between 2021 and 2022. Methods Cycloplegic refraction was measured using an automated refractometer, and ocular biometric parameters were examined using the Lenstar 900. Pre-myopia was defined as an equivalent spherical refraction (SE) of >-0.50 D and ≤+0.75 D. Statistical analyses were conducted using chi-square tests, t tests, Spearman rank correlation, and binary logistic regression. Receiver operating characteristic (ROC) curve analysis was used to determine the threshold values for diagnosing pre-myopia. Main Outcome Measures  Pre-myopia prevalence, refraction, axial length/corneal radius (AL/CR) ratio, and axial length. Results The average age of preschool children in the study, was (4.99±0.76) years, with 773 males (52.5%). The average SE was (1.23±0.90) D for all subjects included, and the prevalence of pre-myopia was 23.4%. No significant differences in prevalence of pre-myopia were found between males and females, different ages, or grades. Among ocular biometric parameters, the AL/CR ratio showed the strongest association with pre-myopia (OR=1282516.4, 95% CI: 74224.2~22160548.9, P<0.01), followed by AL (OR=2.2, 95% CI: 1.7-2.8, P<0.01). The area under the ROC curve (AUC) for AL/CR in diagnosing pre-myopia was 0.720, with a threshold of >2.87. The AUC for AL was 0.673, with a threshold of >22.54 mm. Conclusion The study indicates a high prevalence of pre-myopia among preschool children in northern China, with a possible increasing trend compared to previous data. Among the ocular biometric paramerers, AL/CR ratio shows the strongest association with pre-myopia, followed by axial length. Shifting the focus of myopia prevention and control to the preschool period is crucial for reducing the prevalence of pre-myopia and effectively managing myopia in Chinese children and adolescents. (Ophthalmol CHN, 2024, 33: 280-284)

Key words: preschool children, pre-myopia