Retrospective study reveals key predictors of corneal treatment zone area in children, highlighting parameters to optimize customized orthokeratology lens fitting.
Key Points
To identify clinical and lens design factors influencing corneal treatment zone area after 12 months of overnight orthokeratology and to validate an open-source R workflow for measuring treatment zone morphology.
Retrospective evaluation of 239 children (aged 7–16 years) wearing orthokeratology lenses continuously for 12 months across four groups: VST-S (5.5 mm, n=61), VST-L (6.0 mm, n=66), CRT-S (5.0 mm, n=59), and CRT-L (6.0 mm, n=53).
Compared open-source R-based measurements of treatment zone parameters against MATLAB using Cronbach's alpha and intraclass correlation coefficients.
Evaluated morphological predictors of treatment zone area using Spearman correlation analysis and multiple linear regression.
R and MATLAB demonstrated strong agreement for treatment zone decentration (Cronbach's alpha = 0.993, ICC = 0.986) and treatment zone area (Cronbach's alpha = 0.991, ICC = 0.983).
The VST-L group achieved a significantly larger treatment zone area than the CRT-L group (Mann-Whitney U = 719.000, P < 0.001) and all other cohorts (P < 0.001).
Corneal mean keratometry change (standardized coefficient = 0.963), decentration, shape factor change, baseline shape factor, and back optic zone diameter independently predicted treatment zone area (R² = 0.730).