Prospective Cohort Comparison of Visual Acuity and Contrast Sensitivity Between Femto Laser In Situ Keratomileusis and Orthokeratology for Low-to-Moderate Myopia.

Abstract

To compare the visual acuity and contrast sensitivity (CS) after femto laser in situ keratomileusis (fLASIK) and orthokeratology (OK) in patients with low-to-moderate myopia. A total of 68 patients were enrolled in this prospective cohort study. Of these, 40 eyes from 40 patients with low-to-moderate myopia underwent fLASIK and 28 eyes from 28 patients underwent OK. In addition to uncorrected distance visual acuity and corrected distance visual acuity, photopic and mesopic CS (with CSV-1000E) were tested before treatment and at 1, 3, and 6 months after treatment. The preoperative refraction and CS were not significantly different between the groups (P>0.05). Postoperative visual acuity and refraction were similar (P>0.05). The photopic CS of the fLASIK group was better than that of the OK group (P<0.01). The fLASIK mesopic CS was better than the OK at 3 c/d (P=0.023). In the fLASIK group, only the photopic CS of postoperative 12 c/d decreased at 1 month and 3 months (P<0.01) and 18 c/d decreased at 1 month (P=0.002); whereas in the OK group, all the postoperative photopic CS values decreased at 1 month (all P<0.01) and 3 months (P<0.05) and increased to the normal level at 6 months (P>0.05). While as to the mesopic CS, in the fLASIK group, the 3 c/d, 6 c/d, and 18 c/d decreased at 1 month (P<0.05) and in the OK group, the 3 c/d decreased at 1 month and 3 months (P<0.05) and the 6 c/d decreased at 3 months (P=0.041), and the 12 c/d and 18 c/d decreased at 1 month (P<0.01). These results show that fLASIK provides better visual quality than OK for patients with low-to-moderate myopia.