[Effects after orthokeratology on corneal topography and monochromic wavefront aberration]

Abstract

Objective: To assess the corneal topography and monochromatic wavefront aberration among subjects using orthokeratology. Changes of ocular optical quality and related visual functions induced by corneal topography were studied.

Methods: Twenty-five young myopic subjects (50 eyes) were recruited with myopia from -1.75 approximately -4.75 D. Orthokeratology lens were fitted at the initial visit with overnight wear program. Subjective refraction, corrective visual acuity, corneal topography and slit lamp examination were performed before and 1 day, 1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks after the fitting of orthokeratology lens. The monochromic wavefront aberration was measured in initial visit and after 12 weeks.

Result: The best corrected visual acuity was reduced significantly from (-0.0628 +/- 0.0286) LogMAR (before orthokeratology) to -0.0120 +/- 0.0318 (12 weeks after orthokeratology) (F = 17.821, P < 0.001). Root-mean-square (RMS) of wavefront aberration increased significantly from (0.5766 +/- 0.4771) micro m (before orthokeratology) to (1.3731 +/- 0.8039) micro m (12 weeks after orthokeratology) (F = 36.513, P < 0.001). RMS of Zernike function of each order was increased as well. The rate of eccentric in posterior surface of corneal increased significantly after the using of orthokeratology lens.

Conclusions: Orthokeratology is one of the effective methods for reducing myopia temporarily. However, the best corrected visual acuity is decreased after using of orthokeratology. The increase of aberration induced by orthokeratology can be the cause of reduction of ocular optical quality.