Characterization of the orbital volume in normal population.

INTRODUCTION: The aim of the study was to describe the normal orbital volume and its most important relationships with other clinical variables.

METHODS: We designed a correlation study and consecutive normal CTs scans were included. Orbital volume and facial anthropometrics were measured and correlated between them. Two independent and blind observers made all the measurements. Uni and multivariate statistical analysis were performed in order to create a predicting model for orbital volume.

RESULTS: A total of 199 consecutive patients were included in the study (398 orbits). The mean Orbital Volume (OV) was 24.5 ± 3.08 cc. Adequate intra and interobserver reliability was observed. There were no differences between the right and left orbit (p=0.73). The male average OV was 24.9 ± 3.03 cc, the female OV was 23.9 ± 3.08 cc. Age group analysis demonstrated a slow increase in OV beyond thirty years, but these differences were not significant (p=0.98). Only the age, total facial height, facial width and the interorbital distance were significant and were included in the predictive model of OV.

CONCLUSION: We have characterized the normal orbital volume,variations and associations. In order to further advance in the understanding of the clinical implications the abnormal orbital volume must be fully studied.