关键词: 近视, 轴率比

Abstract:  Objective To investigate the differential characteristics of AL/CR（axial length/corneal radius） in adolescents with different degrees of myopia, to evaluate its utility as an auxiliary tool for screening myopia severity under non-cycloplegic conditions, and to explore its correlation with spherical equivalent (SE) and the optimal diagnostic threshold for screening. Design Cross-sectional study. Participants Include a total of 5779 adolescents aged 7~15 years in Beijing with low myopia （-1.00≥SE>-3.00 D）, moderate myopia （-3.00≥SE>-6.00 D）, and high myopia (≤-6.00 D). Methods AL and CR were measured and AL/CR was calculated. The differences between groups were compared by analysis of variance, and the strength of association of AL/CR with SE was clarified by Pearson's correlation analysis, and the receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the sensitivity, specificity, and optimal cutoff value of AL/CR for diagnosing different degrees of myopia. Main Outcome Measures AL, CR, AL/CR, AUC. Results With the increase of myopia, AL increased from (24.18±0.90) mm to (26.26±1.12) mm (P<0.001), and AL/CR increased from 3.08±0.10 to 3.39±0.16 (P<0.001). AL/CR showed a significant negative correlation with SE (r=-0.363 in the low myopia group, r=-0.466 in the moderate myopia group, r=-0.395 in the high myopia group, all P<0.001). The ROC curve analysis showed that AL/CR had good diagnostic efficacy for low myopia (AUC=0.885), moderate myopia (AUC=0.806), and high myopia (AUC=0.924), with the best results in the high myopia group. The optimal cutoff values for AL/CR were 3.178 for low myopia, 3.161 for moderate myopia, and 3.264 for high myopia, respectively. Conclusions The AL/CR ratio increases significantly with the severity of myopia in adolescents and exhibits a strong negative correlation with SE. AL/CR provides effective diagnostic performance for low, moderate, and high myopia (particularly high myopia) under non-dilated conditions.

Key words: Myopia, Axial length-to-corneal curvature ratio