Long-term effects of monocular myopic anisometropia correction on uncorrected ocular axial length in minors and its influencing factors

Introduction/Objective. To investigate the long-term effects of orthokeratology (ortho-k) correction for monocular myopia and the factors influencing axial length (AL) changes in the untreated eye of minors. Methods. A total of 81 patients with monocular myopia receiving ortho-k lenses for the first time were enrolled. Eyes corrected with ortho-k lenses were designated as the myopic group and contralateral non-myopic eyes formed the non-myopic group. Changes in AL from baseline to follow-up examinations were recorded. Univariate and multivariate linear regression analyses were performed sequentially to explore the correlation between baseline parameters and AL changes in the non-myopic eyes. Results. After wearing ortho-k lenses for 6 and 12 months, the AL of the corrected myopic eye group was 24.48 ? 0.35 and 24.56 ? 0.31 mm, respectively, whereas that of the uncorrected non-myopic eye group was 23.55 ? 0.24 and 23.7 ? 0.22 mm, respectively. After 6 and 12 months, the amount of change in the AL was higher in the uncorrected non-myopia group than in the corrected myopic eye group (P < 0.001). Moreover, the difference in AL between the two eyes gradually decreased (t = 2.376, P = 0.018); the change in AL difference (?0.10 ? 0.08 vs ?0.18 ? 0.13, P < 0.001) was significant. Conclusion. Orthokeratology lens wear may accelerate myopia progression in contralateral initially non-myopic eyes. Younger children with monocular myopia and a higher baseline spherical equivalent are likely to experience faster myopia progression in the other, unaffected eye following ortho-k lens correction.