To analyze the correlation between ocular biometric parameters and cycloplegic refractive shift (ΔSE) and to provide evidence for clinical decision-making regarding cycloplegic refraction in pediatric myopia management.

This retrospective study enrolled myopic patients aged 5-17y between July 2022 and November 2023. Data collected included age, gender, pre-cycloplegic spherical equivalent (SE₁), axial length (AL), average corneal curvature (K), lens thickness (LT), anterior chamber depth (ACD), central corneal thickness (CCT), positive relative accommodation (PRA), negative relative accommodation (NRA), and post-cycloplegic spherical equivalent (SE₂). Only right eyes were analyzed. Participants were divided into three groups by ΔSE: Group A (ΔSE≤0.25 D), Group B (0.25<ΔSE<0.75 D), and Group C (ΔSE≥0.75 D). Based on SE₂, subjects were classified into pre-myopia (−0.50<SE₂≤+0.75 D), low myopia (−3.00<SE₂≤−0.50 D), and moderate myopia (−6.00<SE₂≤−3.00 D).

A total of 996 myopic patients (455 boys, 541 girls) with a mean age of 9.97±0.83y were included. Groups A, B, and C comprised 544, 284, and 168 eyes, respectively. Post-cycloplegic stratification identified 94 pre-myopic eyes, 797 low myopic eyes, and 105 moderate myopic eyes. Significant inter-group differences were observed in AL, CCT, ACD, LT, NRA, and axial length/corneal radius (AL/CR; all P<0.05). LT was positively correlated with ΔSE (P=0.003), while NRA was negatively correlated with ΔSE (P=0.049). AL/CR showed the strongest negative association (P<0.001). ROC curve analysis yielded area under the curve (AUC) values of 0.551 for LT, 0.447 for NRA, and 0.441 for AL/CR. For LT, the optimal cutoff was 3.39 mm, with 65.4% sensitivity and 44.2% specificity. Mean LT was 3.438±0.168 mm in the 5-7-year group, significantly thicker than in 8-10y (3.360±0.145 mm), 11-13y (3.353±0.158 mm), and 14-17y (3.336±0.155 mm; all P<0.001). Median AL/CR ratios were 3.02 (2.95, 3.08) in pre-myopia, 3.10 (3.06, 3.14) in low myopia, and 3.21 (3.15, 3.28) in moderate myopia. Linear regression produced the model: AL/CR=3.025-0.051×SE₂ (R²=0.462, F=854.081, P<0.001). Receiver operating characteristic (ROC) analysis for moderate myopia detection showed an AUC of 0.851 with an optimal AL/CR cutoff of 3.15.

In myopic patients aged 5-17y, ΔSE is negatively correlated with NRA and positively correlated with LT. Cycloplegic refraction is recommended when LT exceeds 3.39 mm, but interpretation must account for age-related variations in lens thickness. Using the formula AL/CR=3.02-0.05×SE₂, cycloplegic refraction is advised when a marked discrepancy exists between pre-cycloplegic refraction and AL/CR.