The Aberrometric Effect of Corneal Plus Power Ring Distribution on Axial Length Growth in Myopic Children Undergoing...

Myopia progression is strongly associated with axial length (AL) elongation, and orthokeratology (Ortho-K) lens design may influence treatment outcomes. This study has the aim to evaluate the impact of lens customization as optical zone diameter between specific higher-order aberrations (HOA) and axial length (AL) changes in myopic children.

This retrospective study evaluated 66 Caucasian myopic children (mean age, 13.3 ± 1.4 years, 60% male) fitted with Ortho-K lenses with varying back optic zone diameters (BOZD, 4.7-6.0 mm) in a Spanish optometric clinic. Baseline mean spherical equivalent (sphere + 1/2 cylinder) was -2.94 ± 1.24 D and AL = 24.52 ± 0.80 mm.

After 12 months, children fitted with smaller BOZDs showed significantly less axial elongation than those with larger BOZDs (0.08 ± 0.12 mm vs. 0.15 ± 0.10 mm, p < 0.001) and smaller plus power ring diameter (PPRD). Differences in AL change were observed between PPRD subgroups (larger and smaller than 4.5 mm). HOA revealed distinct patterns: vertical coma increased significantly only in the PPRD > 4.5 mm group (p = 0.003), horizontal coma increased significantly only in the PPRD < 4.5 mm group (p = 0.004), while total coma increased in both, without intergroup differences. Both PPRD subgroups demonstrated significant increases in spherical aberration (p < 0.001).

These findings suggest that reducing BOZD, and consequently PPRD, can slow AL elongation more effectively than standard designs, although optical side effects require consideration. Further studies should clarify the interplay of BOZD, PPRD, and pupil size in myopia control.