In the past decade, there has been an opinion that ortho-K can contribute to greater mid-peripheral corneal re-shaping in the higher myopic eyes, where the phenomenon of peripheral retinal defocus should also be stronger, thus effectively inhibiting AL growth. Consistent with this idea, some previous studies have shown that a higher baseline spherical equivalent refraction (SER) was associated with slower axial elongation in ortho-K subjects. In the present meta-analysis, where all our included studies employed a contralateral comparison design, the findings revealed that higher myopic eyes showed slower progression of AL elongation in the unilateral myopic group and bilateral anisomyopic group, indicating a dose–response effect that led to the suppression of anisomyopia. This comparative method rendered the findings highly reliable by minimizing the impact of individual differences. Therefore, our results support a possible positive correlation between baseline myopia and the inhibitory magnitude of axial growth by the ortho-K lens.
Overall an interesting review article. It provides excellent data to support that ortho-K is a good option even if only needed in one eye.