title: Model-based improvements in the treatment of patients with strabismus and axial high myopia.
abstract: OBJECTIVE
  Eye motility disorders with axial high myopia and an enlarged globe are often characterized by a hypotropia of the affected eye, usually referred to as heavy-eye syndrome. Based on an intuitive interpretation of magnetic resonance (MR) images, the cause of the hypotropia has typically been assigned to the rectus muscles. In this study, the hypothesis that the oblique muscles play an important role in the underlying biomechanical disorder of this type of strabismus was investigated.
  
  
  METHODS
  The hypothesis was tested by (1) a retrospective analysis of surgical results in one patient with unilateral axial high myopia; and (2) MR images of orbital tissues in two further patients with unilateral axial high myopia.
  
  
  RESULTS
  MR images demonstrated a pattern of extraocular muscle path displacements similar to those described previously, but also a uniform decrease in the cross-sectional area of the inferior oblique muscles. Computer modeling required decreased inferior oblique contractility in addition to displaced extraocular muscle paths to recreate the observed motility pattern accurately.
  
  
  CONCLUSIONS
  Patients with axial high myopia regularly show a reduction in the diameter of the inferior oblique. The resultant reduction in muscle-strength is important for the correct explanation of this complex eye movement disorder.
authors.affiliation: Department of Ophthalmology, Krankenhaus der Barmherzigen Schwestern (Good Sisters Hospital), Ried, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Hoerantner
authors.forename: Thomas
authors.initials: T
authors.lastname: Kaltofen
authors.forename: Siegfried
authors.initials: S
authors.lastname: Priglinger
authors.forename: Christian-Michael
authors.initials: CM
authors.lastname: Fock
authors.forename: Michael
authors.initials: M
authors.lastname: Buchberger
authors.forename: Thomas
authors.initials: T
authors.lastname: Haslwanter
mesh_terms: D000328:Adult; D003198:Computer Simulation; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D012189:Retrospective Studies; D013285:Strabismus / Q000503:physiopathology / Q000601:surgery*; D013577:Syndrome; D013709:Tendon Transfer