Diagnostic performance of isolated orbital CT scan for assessment of globe rupture in acute blunt facial trauma.

OBJECTIVES

We determine the diagnostic performance of emergent orbital computed tomography (CT) scans for assessing globe rupture in patients with blunt facial trauma.

METHODS

We performed a retrospective cohort study based on prospectively collected trauma registry and acute care surveillance data in a tertiary-care hospital. Patients aged at least 18 years who underwent isolated orbital CT scanning for assessing potential ocular trauma were examined. Analyses were performed to evaluate the magnitude of agreement between diagnosis by CT scanning and ophthalmic assessment, including globe rupture.

RESULTS

Our study cohort comprised 136 patients, 30% of whom (41 patients) sustained orbital wall fractures. Concordance for orbital CT diagnosis and the ophthalmic assessment of globe rupture was substantial (k=0.708). The relative risk of globe rupture was 0.692 (95% confidence interval (CI): 0.054-8.849) for superior wall fractures, 0.459 (95% CI: 0.152-1.389) for inferior wall fractures, 2.286 (95% CI: 1.062-4.919) for lateral wall fractures, and 0.637 (95% CI: 0.215-1.886) for medial wall fractures. According to multivariate analysis, lateral wall fractures were an independent risk factor for globe ruptures (adjusted odds ratio (OR)=12.01, P=0.011), and medial or inferior wall fracture was a protective factor (adjusted OR=0.14, P=0.012). In the stratified analysis of diagnostic performance of CT scan, specificity was highest among patients with orbital wall fractures (97.2%), followed by negative predictive volume (NPV, 97%), and accuracy (95.1%).

CONCLUSION

Among patients with blunt facial trauma who underwent isolated orbital CT scanning as part of ocular trauma assessment, the diagnostic performance of CT in detecting globe rupture is more accurate in patients with orbital wall fractures. Nevertheless, isolated orbital CT alone does not have a sufficiently high diagnostic performance to be reliable to rule out all globe ruptures. Lateral orbital wall fractures in blunt facial trauma patients, in particular, should prompt thorough evaluation by an ophthalmologist.