Relationship of inferior oblique overaction to muscle bulk and position

introductionThe 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.MethodsIn 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.ResultsOverall, 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).ConclusionThere was no detectable correlation of inferior oblique overaction with either muscle position or circumference.