title: Relationship of inferior oblique overaction to muscle bulk and position.
abstract: BACKGROUND
  The possible association between inferior oblique muscle overaction and inferior oblique muscle mass has been a matter of speculation. This study was performed to evaluate the anatomical position of the inferior oblique muscle and to determine any association between muscle mass and inferior oblique muscle overaction.
  
  
  METHODS
  In this observational case series, eyes undergoing primary surgery for inferior oblique overaction underwent measurement of inferior oblique muscle borders distance from the limbus and muscle belly circumference.
  
  
  RESULTS
  Overall, 78 eyes of 51 patients with mean age of 18.3 +/- 12.3 years (range, 1-48) were evaluated. The mean distance of the anterior margin of the inferior oblique muscle from the limbus was 16.3 mm +/- 1.8 mm. The distance for the posterior margin was 20.8 mm +/- 1.9 mm. Average muscle circumference was 10.7 mm +/- 0.9 mm (range, 9 to 13). Inferior oblique muscle overaction and muscle belly circumference were not significantly correlated (p = 0.8).
  
  
  CONCLUSIONS
  There was no detectable correlation of inferior oblique overaction with either muscle position or circumference.
authors.affiliation: Department of Ophthalmology, Labbafinejad Medical Center, Shaheed Beheshti Medical University, Tehran, Iran. abbasbagheri@yahoo.com
authors.forename: Abbas
authors.initials: A
authors.lastname: Bagheri
authors.forename: Mohammad
authors.initials: M
authors.lastname: Eshaghi
authors.forename: Shahin
authors.initials: S
authors.lastname: Yazdani
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006984:Hypertrophy; D007223:Infant; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D009801:Oculomotor Muscles / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D013508:Ophthalmologic Surgical Procedures; D012720:Severity of Illness Index; D020432:Trochlear Nerve Diseases / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D055815:Young Adult