Table 1 Inclusion criteria

Age

Subjects were 7–14 years of age

Visual acuity

Had no other ocular diseases aside from refractive error and no keratoconus (confirmed by pre-treatment corneal topography)

Refractive errors

Had an intraocular pressure (IOP) of <21 mmHg

Ocular health

Had an with-the- rule astigmatism (axes 180 ± 30) ≤ 1.50 D

Had a BCVA (best corrected visual acuity) ≤0.00 log MAR units in both eyes (Snellen equivalent to 20/20)

Had no binocular vision problems

Others

No medications that might affect refractive development

Had no history of ortho-k or contact lens wear

Maintained regularly scheduled visits and completed the 2-year follow-up

Had no significant deviations during lens wear (criteria only for ortho-k group)

Discontinued lens wear a total of 30 days or less during the 2 years (criteria only for ortho-k group)