Normal measurements of extraocular muscle using computed tomography.
OBJECTIVE
Establish criteria for the diameters of normal extraocular muscles using computerized tomography in a Thai population.


METHODS
Diameters of extraocular muscles (medial, lateral, superior complex, and inferior rectus) were calculated for 200 patients on coronal direction of screening paranasal sinuses. The effects of age and sex were also analyzed.


RESULTS
Normal ranges for the diameters (mean +/- 2 SDs) of extraocular muscles were 3.7 +/- 0.9 mm for medial rectus, 3.6 +/- 1.2 mm for lateral rectus, 4.0 +/- 1.4 mm for inferior rectus and 3.8 +/- 1.4 mm for the superior group. The mean diameter of the extraocular muscles in male patients was not significantly larger than in female patients (p > 0.05). There was also no statistically significant correlation between age, diameter of each extramuscular muscle and the sum of all four muscles.


CONCLUSIONS
The present result may help radiologists and ophthalmologists to accurately assess enlargement of the extraocular muscles, particularly in Oriental populations.
Lerdlum
Sukalaya
S
Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand. fmedsll@md2.md.chula.ac.th
Boonsirikamchai
Piyaporn
P
Setsakol
Ekapol
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009298:Nasal Polyps; D015588:Observer Variation; D009801:Oculomotor Muscles / Q000033:anatomy & histology*; D010865:Pilot Projects; D012016:Reference Values; D012189:Retrospective Studies; D012852:Sinusitis; D013785:Thailand; D014055:Tomography, Emission-Computed