title: A case of unilateral congenitally enlarged extraocular muscles.
abstract: BACKGROUND
  Enlargement of extraocular muscles is an uncommon finding in children. Little has been written in the literature about possible causes.
  
  
  METHODS
  The authors present the clinical findings of a young girl who had unilateral congenitally enlarged extraocular muscles at 8 months of age. She underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans, systemic assessment, and extraocular muscle biopsy to determine a cause for the enlarged muscles.
  
  
  RESULTS
  The patient had a unilateral left esotropia and hypotropia at birth that was nonprogressive. High-resolution CT and MRI scans showed enlargement of the left inferior rectus, lateral rectus, and medial rectus muscles. Strabismus surgery undertaken at 2 years of age showed that the affected muscles were restricted on forced duction testing but were macroscopically normal in appearance. A biopsy specimen of the left lateral rectus muscle was processed for histologic, histochemical, and electron microscopic studies, but no abnormal pathologic findings were found.
  
  
  CONCLUSIONS
  This patient's constellation of findings appears to be unique: it does not follow any previously reported pattern of disorders of extraocular muscle enlargement.
authors.affiliation: Department of Ophthalmology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: J S
authors.initials: JS
authors.lastname: Dickson
authors.forename: S P
authors.initials: SP
authors.lastname: Kraft
authors.forename: V
authors.initials: V
authors.lastname: Jay
authors.forename: S
authors.initials: S
authors.lastname: Blaser
mesh_terms: D001706:Biopsy; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D009801:Oculomotor Muscles / Q000002:abnormalities* / Q000473:pathology; D013285:Strabismus / Q000151:congenital* / Q000175:diagnosis; D014057:Tomography, X-Ray Computed