title: Changes in fusional vergence amplitudes after laser refractive surgery for moderate myopia.
abstract: OBJECTIVE
  To analyze the effect of bilateral laser refractive surgery on fusional vergence amplitude and near point convergence in normal orthotropic myopic patients.
  
  
  METHODS
  Cornea and refractive private practice, Seoul, South Korea.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Moderately myopic patients (2.0 to 6.0 diopters [D]) had bilateral laser refractive surgery with postoperative follow-ups at 1 week and 1 and 3 months. Patients with manifest strabismus, previous strabismus surgery, amblyopia, absent or impaired binocularity, or planned monovision were excluded. The preoperative and postoperative examinations included uncorrected and corrected visual acuities; a prism cover test; evaluation of the convergence, divergence, and vertical fusion amplitude using a rotary prism; and near point convergence.
  
  
  RESULTS
  The mean age of the 30 patients was 29 years ± 4 (SD). The mean preoperative refractive error was -4.10 ± 1.32 D in right eyes and -4.14 ± 1.37 D in left eyes. The convergence amplitude at near decreased 1 week and 1 month postoperatively, after which it progressively stabilized to near preoperative values. The convergence amplitude at far (break point) was not changed postoperatively; however, the convergence amplitude at far (recovery point) was increased at 1 month and 3 months (P=.008 and P=.003, respectively). There was a slight increase in near point convergence at 3 months (P<.001).
  
  
  CONCLUSIONS
  Although fusional vergence amplitudes at near and near point convergence changed after laser refractive surgery, the changes observed were small or transient. However, patients with latent phoria or strabismus should be warned before having refractive surgery.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Institute of Vision Research (J. Han, Hong, H.K. Lee, S-H Han), Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, SU Yonsei Eye Clinic (S. Lee), and B & VIIT Eye Center (Kim), Seoul, South Korea.
authors.forename: Jinu
authors.initials: J
authors.lastname: Han
authors.affiliation: From the Institute of Vision Research (J. Han, Hong, H.K. Lee, S-H Han), Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, SU Yonsei Eye Clinic (S. Lee), and B & VIIT Eye Center (Kim), Seoul, South Korea.
authors.forename: Samin
authors.initials: S
authors.lastname: Hong
authors.affiliation: From the Institute of Vision Research (J. Han, Hong, H.K. Lee, S-H Han), Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, SU Yonsei Eye Clinic (S. Lee), and B & VIIT Eye Center (Kim), Seoul, South Korea.
authors.forename: Seungjae
authors.initials: S
authors.lastname: Lee
authors.affiliation: From the Institute of Vision Research (J. Han, Hong, H.K. Lee, S-H Han), Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, SU Yonsei Eye Clinic (S. Lee), and B & VIIT Eye Center (Kim), Seoul, South Korea.
authors.forename: Jin Kook
authors.initials: JK
authors.lastname: Kim
authors.affiliation: From the Institute of Vision Research (J. Han, Hong, H.K. Lee, S-H Han), Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, SU Yonsei Eye Clinic (S. Lee), and B & VIIT Eye Center (Kim), Seoul, South Korea.
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Lee
authors.affiliation: From the Institute of Vision Research (J. Han, Hong, H.K. Lee, S-H Han), Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, SU Yonsei Eye Clinic (S. Lee), and B & VIIT Eye Center (Kim), Seoul, South Korea. Electronic address: shhan222@yuhs.ac.
authors.forename: Sueng-Han
authors.initials: SH
authors.lastname: Han
mesh_terms: D000328:Adult; D003290:Convergence, Ocular / Q000502:physiology*; D005260:Female; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult