Fig. 1

Two representative patients after one month of orthokeratology lens wearing with different back optic zone diameters (BOZDs). The upper row is patient A with a 5-mm BOZD, and the lower row is patient B with a 6-mm BOZD. Fluorescein pattern images of (a) patient A with 5-mm BOZD lenses and (b) patient B with 6-mm BOZD lenses. Clinical tangential power difference map of (c) patient A and (d) patient B showed that the radius of treatment size was 1.67 mm and 2.24 mm, respectively. Reproduction of the Zernike defocus coefficient in three-dimensional space of (e) patient A was 6.91 D and (f) patient B was 4.29 D. High-order aberrations of (g) patient A were 1.98 root mean square (RMS), and (h) patient B was 0.94 RMS. The baseline spherical equivalent (− 2.75 D) and age (9 years old) were similar, and the 12-month axial elongation was 0.05 and 0.34 mm, respectively