Figure 1From: Overnight orthokeratology is comparable with atropine in controlling myopia Increases in axial length (mm) and refractive errors (myopia [D]) at baseline in the OK group. A significant correlation was found between the increases in axial length and spherical equivalent refractive errors (myopia [D]) at the baseline. Pearson’s correlation coefficient: r = 0.259, p < 0.001.Back to article page