The relationship between relative peripheral refraction and axial length elongation in myopic children wearing orthokeratology lenses using a novel wide-angle multispectral refraction topographer.

Purpose: To investigate the peripheral retinal relative defocus in myopic children wearing orthokeratology (OK) lenses and evaluate its relationship with the efficacy of myopia control.

Methods: Wide-angle (150° field of view) relative peripheral refraction and axial length measurements were conducted in 48 children wearing OK lenses. Key peripheral refraction parameters included minimum defocus distance, defocus ring outer diameter, defocus ring inner diameter, defocus ring width, and retinal relative defocus values (RDVs). Pearson correlation analysis was used to evaluate the associations between axial elongation rate and these parameters. Multiple regression analysis was constructed to predict axial elongation, mainly based on the parameters of peripheral retinal defocus.

Results: Peripheral myopic defocus was observed in children wearing OK lenses. Axial elongation rate showed a negative correlation with defocus ring outer diameter (R = -0.388, P < 0.01) and defocus ring width (R = -0.503, P < 0.01), while it was positively correlated with minimum defocus distance (R = 0.383, P < 0.01) and defocus ring inner diameter (R = 0.309, P < 0.01). RDV-53, RDV-45, RDV-(30-45), RDV-(45-53), RDV-N, and RDV-I also showed significant positive correlations with axial elongation rate (P < 0.01). Age, baseline axial length, defocus ring width, minimum defocus distance, and RDV-(45-53) were five predictors in the multivariable prediction model.

Conclusion: Wearing OK lenses induced peripheral myopic defocus. Larger defocus ring width, closer defocus ring to the macular zone and greater relative peripheral myopic defocus were associated with less axial elongation. Peripheral defocus parameters combined with age and baseline axial length could predict axial elongation to some extent.