extraconal haematoma

Retrobulbar hemorrhage is the presence of a post septal orbital hematoma and is usually due to craniofacial trauma causing an extraconal hematoma. It may cause orbital compartment syndrome which is an ophthalmologic emergency.

Clinical features

If small, there may be no orbital or ocular symptoms. If large enough to create mass effect on the contents of the orbit (particularly the optic nerve) and orbital compartment syndrome, features include:

• visual disturbance
• proptosis
• pain
• orbital bruising and swelling
• features of head and/or facial trauma

Etiology

The most common cause is trauma, almost always secondary to orbital fractures. Other causes include:

• orbital surgery
• other surgery e.g. sinus or neurosurgical procedures
• hemorrhage from an intraorbital vascular mass e.g. orbital vascular malformation or metastases
• coagulopathies

Radiographic features

CT is the primary imaging modality for cranio-orbital trauma. The orbit is best assessed in bone and soft tissue coronal reconstructions.

Extraconal hematoma has a classic appearance of a confined lentiform hyperdense hematoma, analagous to an intracranial extradural hemorrhage. It is usually located in the superior half of the orbit and almost always adjacent to a fracture of the bony orbit. If large enough they can exert mass effect on the contents of the orbit, causing stretching of the optic nerve and proptosis.

Extraconal hematomas can be difficult to distinguish from a subperiosteal hematoma.

Treatment

Orbital compartment syndrome is an ophthalmologic emergency and requires urgent lateral canthotomy and cantholysis to decompress the orbit and preserve ocular function.