title: Impact of laser refractive surgery on ocular alignment in myopic patients.
abstract: OBJECTIVE
  To evaluate the impact of myopic keratorefractive surgery on ocular alignment.
  
  
  METHODS
  This prospective study included 194 eyes of 97 myopic patients undergoing laser refractive surgery. All patients received a complete ophthalmic examination with particular attention to ocular alignment before and 3 months after surgery.
  
  
  RESULTS
  Patients with a mean age of 26.6 years and a mean refractive error of -4.83 diopters (D) myopia were treated. Asymptomatic ocular misalignment was present preoperatively in 46 (47%) patients: a small-angle heterophoria (1-8 prism diopters, PD) in 36%; and a large-angle heterophoria (>8 PD)/heterotropia in 11%. Postoperatively, the change in angles of 10 PD or greater occurred in 3% for distance and 6% for near fixation: in 7% of the patients with orthophoria, in 3% of those with a small-angle heterophoria, and in 18% of those with a large-angle heterophoria/heterotropia. No patient developed diplopia. The preoperative magnitude of myopia or postoperative refractive status was not related to the change in ocular alignment. The higher anisometropia was associated with a decrease in deviation (P=0.041 for distance and P=0.002 for near fixation), whereas the further near point of convergence tended to be related with an increase in near deviation (P=0.055).
  
  
  CONCLUSIONS
  Myopic refractive surgery may cause a change in ocular alignment, especially in cases with a large-angle heterophoria/heterotropia. There is also a chance of improvement of misalignment in patients with anisometropia.
authors.affiliation: Department of Ophthalmology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: S A
authors.initials: SA
authors.lastname: Chung
authors.affiliation: B&VIIT Eye Clinic, Seoul, Korea.
authors.forename: W K
authors.initials: WK
authors.lastname: Kim
authors.affiliation: The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: J W
authors.initials: JW
authors.lastname: Moon
authors.affiliation: Department of Ophthalmology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.affiliation: B&VIIT Eye Clinic, Seoul, Korea.
authors.forename: J K
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: S B
authors.initials: SB
authors.lastname: Lee
authors.affiliation: The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: J B
authors.initials: JB
authors.lastname: Lee
mesh_terms: D000328:Adult; D015858:Anisometropia / Q000503:physiopathology*; D003315:Cornea / Q000503:physiopathology*; D003867:Depth Perception / Q000502:physiology; D005260:Female; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D015348:Vision, Binocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult