title: [Analysis of the effectiveness of laser in situ keratomileusis two years after surgery].
abstract: OBJECTIVE
  To evaluate the effectiveness of laser in situ keratomileusis (LASIK) for myopia after 2 year follow-up.
  
  
  METHODS
  LASIK surgery was performed for 95 eyes (49 cases) with refractive dioptres (from -1.00 to -16.50 D), and then followed up for more than 2 years. The preoperative spherical equivalent was -1.00(-)-16.50 (-6.73 +/- 2.02) D. Patients were divided into two groups including group I with mild to moderate myopia (< or = -6.00 D) and Group II with severe myopia (more than -6.00 D).
  
  
  RESULTS
  In group I, uncorrected visual acuity more than and equivalent to 1.0 was in 40 eyes (93.02%), more than and equivalent to 0.8 in 43 eyes (100%). In group II, uncorrected visual acuity larger than and same as 1.0 was in 37 eyes (71.15%), larger than and same as 0.8 in 45 eyes (86.54%), larger than and same as 0.5 in 50 eyes (96.15%), and less than 0.5 in 2 eyes (3.85%). The mean spherical equivalent changed from (-4.14 +/- 0.86) D to (-0.04 +/- 0.14) D in group I and from (-9.00 +/- 1.64) D to (-0.08 +/- 0.20) D in group II. Significant difference was seen in these two groups (P < 0.001). The keratometric powers (K) were reduced from (44.31 +/- 0.78) to (40.11 +/- 1.23) and from (45.46 +/- 1.00) to (38.01 +/- 1.73) respectively, which showed significant difference (P < 0.001).
  
  
  CONCLUSIONS
  The effectiveness of LASIK for mild to moderate myopia or severe myopia is promising and safe.
authors.affiliation: Department of Ophthalmology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China. prk@pumch.an.cn
authors.forename: Yu-mei
authors.initials: YM
authors.lastname: Jin
authors.forename: Guo-xiang
authors.initials: GX
authors.lastname: Pang
authors.forename: Yu-min
authors.initials: YM
authors.lastname: Sun
authors.forename: Zhong-hai
authors.initials: ZH
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D009216:Myopia / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity