title: [An enhancement ablation for undercorrection after excimer laser in situ keratomileusis for myopia].
abstract: OBJECTIVE
  To evaluate the treatment of undercorrection after excimer laser in situ keratomileusis (LASIK) for correction of moderate and high myopia.
  
  
  METHODS
  An enhancement ablation was performed on 48 eyes of 39 patients who had undergone LASIK but had undercorrection. The ablation was performed on 4 eyes after 1 month postoperatively, and on the rest between 3 and 10 months. The surgical techniques included re-inversing the corneal cap from temporal side, excimer laser ablation at corneal stroma, and re-positioning of the cap.
  
  
  RESULTS
  The undercorrection (spherical equivalent) ranged from -2.00 to -11.00 D, mean, -4.34 +/- 1.95 D. Follow-up periods after enhancement were 4 to 12 months, the refraction in 42 eyes was within +/- 1.00 D. Undercorrection of -2.50 to -5.00 D recurred in 6 eyes. The uncorrected visual acuity was equal to the preoperative spectacle corrected visual acuity in 39 of 48 eyes (81.3%). Five eyes gained 1 line, 1 eye gained 2 lines and 4 eyes lost 1 line. No eyes had haze.
  
  
  CONCLUSIONS
  Undereorrection after LASIK can be corrected by an enhancement ablation of the stroma under the primary corneal cap with 193 nm ArF excimer laser, and the time for the enhancement ablation should be over 3 months postoperatively.
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou.
authors.forename: B
authors.initials: B
authors.lastname: Yang
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000379:methods*; D012086:Reoperation; D017211:Treatment Failure