Sometimes the exophthalmos may be obscured by periorbital edema, In this time it can be better appreciated from a superior view. Visual acuity may be affected by the direct trauma to the eye (retinal detachment, hyphema, globe rupture), compression of the retinal artery, or neuropraxia of the optic nerve. The term "Orbital compartment syndrome" occurs when intraorbital pressure exceeds central retinal artery pressure and ocular ischemia ensues. Causes are many with retrobulbar hematoma being the most common.
CT is the best modality to determine both the presence and extent of a retrobulbar hematoma and associated facial or orbital fractures. Consultation of ENT and ophthalmology is indicated on an urgent basis. An emergent lateral canthotomy decompresses the orbit and can be performed in the emergency department and may be sight-saving.
Traumatic Exophthalmos. Blunt trauma resulting in periorbital edema and ecchymosis, which obscures the exophthalmos in this patient. The exophthalmos is not obvious in the AP view and can therefore be initially unappreciated. The Figure below shows the same patient viewed in the coronal plane from over the forehead.
Traumatic Exophthalmos. Superior view, demonstrating the right-sided exophthalmos.