title: Surgical outcomes in convergence insufficiency-type exotropia.
abstract: OBJECTIVE
  To determine the efficacy of different types of strabismus surgeries in patients with convergence insufficiency (CI)-type exotropia, according to their response to diagnostic monocular occlusion.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Sixty-five patients with CI-type exotropia with near-distance differences of ≥10 prism diopters (PD) who underwent strabismus surgery.
  
  
  METHODS
  Patients were divided into 3 groups according to their response to monocular occlusion: (1) true-CI group: near-distance differences ≥10 PD before and after occlusion; (2) masked-CI group: near-distance differences <10 PD before occlusion and ≥10 PD after occlusion; and (3) pseudo-CI group: near-distance differences ≥10 PD before occlusion and <10 PD after occlusion. Either bilateral lateral rectus recession based on near measurements with 1 mm augmentation (BLR) or unilateral medial rectus resection based on the near deviation with lateral rectus recession based on the distant deviation (RR) was performed.
  
  
  METHODS
  Cumulative probabilities of success, near-distance differences of exodeviation, rate of recurrence per person-year, and risk factors of recurrence.
  
  
  RESULTS
  There were 24 children in the true-CI group, 19 children in the masked-CI group, and 22 children in the pseudo-CI group. The cumulative probabilities of success at 2 years after BLR versus RR were 61% versus 100% in the true-CI group, 58% versus 100% in the masked-CI group, and 77% versus 71% in the pseudo-CI group. The RR procedure was significantly more successful than the BLR procedure in the true-CI and masked-CI groups.
  
  
  CONCLUSIONS
  Successful outcome in CI-type exotropia was closely related to the patients' response to monocular occlusion. In patients with CI-type exotropia maintained after monocular occlusion, unilateral resection-recession based on near-distance measurements is recommended.
  
  
  BACKGROUND
  Proprietary or commercial disclosure may be found after the references.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Yang
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Hwang
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003290:Convergence, Ocular / Q000502:physiology; D005099:Exotropia / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D012008:Recurrence; D012030:Refractive Errors / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology