title: The effect of horizontal strabismus surgery on the vertical palpebral fissure width.
abstract: OBJECTIVE
  To compare vertical lid fissure width before and after medial or lateral rectus muscle recessions for horizontal strabismus.
  
  
  METHODS
  In this prospective, noninterventional case series, vertical eyelid fissure width measurements were compared before and after treatment in consecutive patients undergoing extraocular muscle recessions for esotropia or exotropia. Digital imaging analysis was used to measure vertical lid fissure width. Each measurement was an average of three separate images.
  
  
  RESULTS
  A total of 59 subjects were enrolled, including 42 for esotropia and 17 for exotropia. Mean postoperative vertical palpebral fissure width increased by 0.96 mm (11.9%; range, 0.64-2.5 mm) in esotropia patients and 1.00 mm (11.8%; range, 0.19-3.23 mm) in exotropia patients (P < 0.0001 in both groups.)
  
  
  CONCLUSIONS
  Recession of a rectus muscle for comitant horizontal strabismus may result in vertical widening of the palpebral fissure.
authors: Department of Ophthalmology, Antonio Pedro University Hospital, Federal Fluminense University, Niterói, Brazil.
authors: Luiz Cláudio
authors: LC
authors: Santos de Souza Lima
authors: Luis Guilhermo Coca
authors: LG
authors: Velarde
authors: Raul Nunes Galvarro
authors: RN
authors: Vianna
authors: Guilherme
authors: G
authors: Herzog Neto
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004948:Esotropia / Q000601:surgery*; D005099:Exotropia / Q000601:surgery*; D005143:Eyelids / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures / Q000379:methods; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted; D016896:Treatment Outcome; D055815:Young Adult