title: Magnetic resonance imaging of the medial rectus muscle of patients with consecutive exotropia after medial rectus muscle recession.
abstract: OBJECTIVE
  To investigate the morphologic characteristics of the medial rectus muscle in patients with consecutive exotropia.
  
  
  METHODS
  Retrospective, nonrandomized, interventional study.
  
  
  METHODS
  Eleven eyes of 10 patients with consecutive exotropia were studied. Thirteen eyes of 13 age-matched normal subjects were studied as controls.
  
  
  METHODS
  All of the patients underwent an advancement of a previously operated medial rectus muscle. Patients were divided into 3 groups based on the insertion of the medial rectus muscle: Normally recessed stretched scar, and slipped muscle.
  
  
  METHODS
  A comparison was made of the clinical findings, intraoperative findings, and distance from the limbus to the medial rectus muscle measured on magnetic resonance images among the groups.
  
  
  RESULTS
  The medial rectus of 4 eyes of 3 patients had normally recessed insertions and 7 eyes had abnormal insertions (3 stretched scars, 4 slipped muscles). The clinical findings were not different among the 3 groups. The magnetic resonance images showed that the medial rectus muscle was located closest to the limbus in the control subjects and most distant in the patients with a slipped muscle (P<0.005). The clinical findings in the patients with a stretched scar and with normally recessed were indistinguishable.
  
  
  CONCLUSIONS
  Magnetic resonance images of the medial rectus muscles of the control subjects and operated groups are significantly different morphologically. A slipped medial rectus muscle has characteristic magnetic resonance findings that are distinguishable from the muscle with normally recessed and stretched scar.
authors.affiliation: Department of Ophthalmology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Negishi
authors.forename: Akiko
authors.initials: A
authors.lastname: Hikoya
authors.forename: Haruo
authors.initials: H
authors.lastname: Isoda
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tsuchiya
authors.forename: Mayu
authors.initials: M
authors.lastname: Sawada
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hotta
authors.forename: Miho
authors.initials: M
authors.lastname: Sato
mesh_terms: D000328:Adult; D000368:Aged; D005099:Exotropia / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000473:pathology* / Q000601:surgery; D013508:Ophthalmologic Surgical Procedures; D012189:Retrospective Studies