Fig. 2From: Effect of Orthokeratology on myopia progression: twelve-year results of a retrospective cohort studyTrend of refractive error change (a) By different wearing age groups (b) By initial myopic refraction groups (c) By initial astigmatism groups and (d) By stable lens change groups. Asterisk (*) denotes statistically significant difference between OK and control groupsBack to article page