Effects of orthokeratology lens on axial length elongation in unilateral myopia and bilateral myopia with anisometropia children

Purpose: To investigate the effect of orthokeratology (OK) lens on axial length (AL) elongation in unilateral myopia and bilateral myopia with anisometropia children. Methods: Twenty-seven unilateral myopia (group 1) and 25 bilateral myopia with anisometropia children (group 2) were involved in this 1-year retrospective study. The eyes with higher spherical equivalent refractive error (SER) were assigned to the H eyes subgroup and the fellow eyes with lower SER to the L eyes subgroup in the two groups. Results: The mean change in AL of H eyes and L eyes were 0.11 +/- 0.19 mm, 0.30 +/- 0.28 mm in group 1 (P = 0.04) and 0.09 +/- 0.14mm, 0.13 +/- 0.16mm in group 2 (P = 0.36), respectively. Multivariate regression analyses showed that significant difference of change in AL was found between H eyes and L eyes in groupl (beta = 0.25, P = 0.03), but no difference in group 2 (beta = 0.09, P = 0.12). The AL of H eyes in group 1 and group 2, H eyes in group 1 and L eyes in group 2 had the same increased rate (beta = - 0.04, P = 0.43; beta = 0.02, P = 0.56). Conclusions: Monocular OK lens is effective on suppression AL elongation of the myopic eyes and reduce anisometropia value in unilateral myopic children. The OK lens can control the AL elongation in both eyes at the same rate, but it cannot reduce anisometropia value in bilateral myopia with anisometropia children after 1-year follow-up.