Purpose: To assess the differences in visual performance between orthokeratology (ortho-k) and laser in situ keratomileusis (LASIK) for the treatment of low-to-moderate myopia.
Methods: An adaptive optics visual simulator (Imagine Eyes) was used to simulate the wavefront aberration patterns induced by ortho-k and LASIK for low and moderate myopia on 10 healthy eyes. Visual acuity (VA) at 100%, 50%, and 10% contrast levels and contrast sensitivity (CS) at 10, 20 and 25 cycles per degree (cpd) were then measured for 3- and 6-mm pupil sizes.
Results: Differences in VA for 3-mm pupil diameter were not found between ortho-k and LASIK. For 6-mm pupil size, LASIK provided significantly better VA values than ortho-k at 50% and 10% contrast levels for low myopia correction (P = 0.002 and P = 0.001, respectively) and at all contrast levels for moderate myopia correction (P = 0.04 at 100%, P < 0.0001 for 50% and 10% contrast levels). For 3-mm pupil size, differences in CS were not significant between both techniques for low myopia correction and were only significant at 25 cpd (P = 0.03) for moderate myopia correction. For 6-mm pupil diameter, LASIK provided better CS than ortho-k for 20 and 25 cpd for low myopia (P = 0.02 and P = 0.01, respectively) and at all spatial frequencies for moderate myopia (P = 0.02 for 10 cpd and P < 0.0001 for 20 and 25 cpd).
Conclusions: The results in this study suggest that LASIK provides better visual quality outcomes than ortho-k for the treatment of low-to-moderate myopia.