Objective: To evaluate the efficacy and safety of laser in situ keratomileusis (LASIK) for the correction of myopia.
Methods: A total of 429 eyes with preoperative refraction of -2.00 to -28.00 diopters were treated with LASIK and followed up for more than 12 months. Based on the refraction, the patients were divided into 3 groups: Group I, -2.00, to -8.00 diopters, 179 eyes; Groups II, -8.25 to -15.00 diopters, 137 eyes; Group III, -15.25 to -28.00 diopters, 113 eyes. The examinations included cycloplegic refractions, Goldman tonometry, corneal sensitivity, contrast sensitivity, specular microscopy, pachymetry and corneal topography. The parameters of LASIK were: the thickness of corneal cap was 130 or 160 microns, and the maximum diameter of ablation zone was 6.8 mm. After surgery, fluorometholone was given to the patients topically for 1 or 2 months.
Results: The vision and refractions tended to be normal 3 months after operation. The contrast sensitivity returned to normal 3 to 6 months after surgery. The endothelium did not show any changes. At 12 months, respectively 88.8%, 79.6% and 70.8% in the above groups were within +/- 1D, 73.7%, 65.0% and 46.0% were within +/- 0.5D; the uncorrected visual acuity was 0.5 or better in 96.6%, 81.8% and 54.9% of the patients, 84.4%, 58.4% and 15.0% had vision of 1.0 or better.
Conclusions: LASIK is effective and safe for the correction of mild, moderate and high myopia. However, it is more complicated than PRK and more dependent on the surgical skills.