bony interorbital distance and orbital measurements in the Iranian population: a CT study

ABSTRACT

Normal values for CT orbital measurements, which appear in reference books, may not be applicable to the Iranian population. The purpose of this study was to determine normal values in an Iranian population and compare them with published standards. Orbital CT scans from adults were studied from March 2003 to June 2005. The scans had been ordered for complaints unrelated to craniofacial and orbital abnormalities, and in all of them, the presence of any pathology of the bones, globe and orbit were excluded. Four hundred CT scans [134 females, 266 males, mean age 36.9 +/- 16.7 years] were studied. The normal interorbital distance at the posterior border of the frontal process of the maxilla measured from 1.8 to 3.5 cm [mean 2.30] in men and 1.5 to 3.2 cm [mean 2.17] in women [p<0.01]. At the level of orbital equator, the mean interorbital distance was 2.46 cm in women [range 1.7-3.2] and 2.65 cm in men [range 2-3.4] [p<0.01]. Compared with the corresponding values of interorbital standards, all these measurements were smaller. Normal values of orbital measurements are smaller and more varied in Iranian population and these values must be used when interpreting CT scans of the orbit