Reference Values of Non-Cycloplegic Spherical Equivalent for Screening and Predicting Myopia Among Children and Adolescents - China, 2020-2024.

Introduction: Non-cycloplegic refraction is widely utilized in vision screening. However, interpreting non-cycloplegic refraction results remains a significant challenge in both clinical practice and public health settings. This study aimed to establish grade- and sex-specific reference values for non-cycloplegic spherical equivalent (SE) to enhance myopia screening and risk prediction among Chinese students. Methods: A comprehensive study was conducted between 2020 and 2024, involving 67,260 students from kindergarten through high school across 10 provincial-level administrative divisions (PLADs) in China. The Lambda-Mu-Sigma method was employed to model non-cycloplegic SE. Reference values were established by calculating SE centiles corresponding to myopia and high myopia prevalence across grades 0 through 12. Results: Among boys, the estimated prevalence of myopia and high myopia increased from 1.2% and <0.1% in grade 0 (senior kindergarten) to 82.4% and 11.6% in grade 12 (third year of high school), respectively. For twelfth-grade boys, the 82.4th and 11.6th percentiles of SE (-0.99 D and -6.16 D) were established as reference values for screening myopia and high myopia, respectively. The corresponding percentiles in lower grades served as predictive reference values for grade 12 outcomes. For instance, a grade-0 boy with non-cycloplegic SE>0.70 D (82.4th percentile) was predicted to remain free of myopia before grade 12. Similarly, SE>-0.73 D (11.6th percentile) indicated a low likelihood of developing high myopia before grade 12. Conclusions: This study established comprehensive non-cycloplegic SE reference values for screening and predicting myopia among Chinese students. The methodology developed here may be applicable to other regions where student myopia prevalence patterns demonstrate relative stability.