Ultrasonography evaluation of retrobulbar hematoma in bovine orbits

As the proptotic eye is pushed anteriorly against the canthis, pressure within the eye increases until there is inadequate perfusion of the eye due to the pressure effects. computed tomography (CT) scan of the orbit is the most common method of diagnosing a retrobulbar hematoma. In the trauma/emergency department setting, where the wait for a CT scan may present significant delay, bedside ultrasonography may aid in the rapid diagnosis and treatment of a retrobulbar hematoma. OBJECTIVE: To establish concordance between orbital CT scan and a bedside sonographic orbital evaluation of a retrobulbar hematoma. METHODS: Eighteen of 22 bovine orbits were injected with a 10-mL mixture of calcium-treated banked blood and contrast into the retro-orbital space thereby effecting a retrobulbar hematoma. Each orbit was studied with CT and evaluated by a neuroradiologist. Four orbits were left intact as controls. Each orbit underwent an ultrasonographic evaluation. The ultrasonographer was first allowed to study an orbit with a documented hematoma and a control. Thereafter, he was blinded to the orbits containing hematoma, did not physically examine each orbit, and completed each exam in a darkened room. The CT results were correlated with the ultrasound findings. RESULTS: 15 of 18 orbits (83%) were correctly identified as containing hematoma by ultrasound. All four intact orbits were correctly identified as being free of hematoma (kappa 0.6). CONCLUSIONS: Bedside ultrasonography may aid in the rapid diagnosis of a retrobulbar hematoma.