title: Influence of intraocular astigmatism on the correction of myopic astigmatism by laser-assisted subepithelial keratectomy.
abstract: OBJECTIVE
  To assess the influence of the origin of astigmatism on the correction of myopic astigmatism by laser-assisted subepithelial keratectomy (LASEK).
  
  
  METHODS
  Ophthalmology Department, Eye and ENT Hospital, Shanghai, China.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Patients having LASEK to correct myopia or myopic astigmatism were divided into 2 groups according to their ocular residual astigmatism (ORA). Patients were examined preoperatively and 1 and 3 months postoperatively. The efficacy of LASEK was compared between those with and those without a significant amount of intraocular astigmatism.
  
  
  RESULTS
  The study comprised 54 eyes of 54 patients. The mean index of success (ratio of magnitude of remaining uncorrected astigmatism to that of initial preoperative astigmatism) in the high ORA group (n=21) and low ORA group (n=33) was 0.85 and 0.48, respectively, 1 month after surgery (t=2.17, P=.04) and 0.88 and 0.32, respectively, 3 months after surgery (t=2.18, P=.04). The Zernike coefficient of horizontal coma, Z(3,+1), increased more after surgery in the high ORA group than in the low ORA group (1 month versus preoperative, t=2.32, P=.024; 3 months versus preoperative, t=2.07, P=.048).
  
  
  CONCLUSIONS
  Nine percent and 2% of the eyes had minimal corneal haze at 1 month and 3 months, respectively. Laser-assisted subepithelial keratectomy was less effective in correcting myopic astigmatism when astigmatism was mainly located at the internal optics. Horizontal coma increased more after LASEK in patients with higher ORA.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Department of Ophthalmology (Qian, Huang, Chu, Zhou), Eye and ENT Hospital, Fudan University, and the Key Laboratory of Myopia of State Health Ministry (Qian, Huang, Chu, Zhou), Shanghai, China; the Department of Surgery (Olszewski), Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Yishan
authors.initials: Y
authors.lastname: Qian
authors.affiliation: From the Department of Ophthalmology (Qian, Huang, Chu, Zhou), Eye and ENT Hospital, Fudan University, and the Key Laboratory of Myopia of State Health Ministry (Qian, Huang, Chu, Zhou), Shanghai, China; the Department of Surgery (Olszewski), Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Jia
authors.initials: J
authors.lastname: Huang
authors.affiliation: From the Department of Ophthalmology (Qian, Huang, Chu, Zhou), Eye and ENT Hospital, Fudan University, and the Key Laboratory of Myopia of State Health Ministry (Qian, Huang, Chu, Zhou), Shanghai, China; the Department of Surgery (Olszewski), Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Renyuan
authors.initials: R
authors.lastname: Chu
authors.affiliation: From the Department of Ophthalmology (Qian, Huang, Chu, Zhou), Eye and ENT Hospital, Fudan University, and the Key Laboratory of Myopia of State Health Ministry (Qian, Huang, Chu, Zhou), Shanghai, China; the Department of Surgery (Olszewski), Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA. Electronic address: jitong0512@163.com.
authors.forename: Xingtao
authors.initials: X
authors.lastname: Zhou
authors.affiliation: From the Department of Ophthalmology (Qian, Huang, Chu, Zhou), Eye and ENT Hospital, Fudan University, and the Key Laboratory of Myopia of State Health Ministry (Qian, Huang, Chu, Zhou), Shanghai, China; the Department of Surgery (Olszewski), Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Olszewski
mesh_terms: D057128:Aberrometry; D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology*; D063171:Corneal Pachymetry; D057108:Corneal Wavefront Aberration / Q000503:physiopathology; D005260:Female; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D016896:Treatment Outcome; D055815:Young Adult