What clinical findings, imaging studies, and emergency interventions are indicated for diagnosing and managing a retrobulbar hematoma?

Retrobulbar Hematoma Diagnosis

Retrobulbar hematoma is a clinical diagnosis requiring immediate recognition and treatment based on specific examination findings—do not delay intervention waiting for imaging if clinical signs are present. 1

Clinical Diagnostic Criteria

The diagnosis is established by identifying the following constellation of findings on physical examination:

• Proptosis (forward displacement of the globe) is the hallmark sign 1, 2
• Decreased visual acuity or progressive vision loss 1, 2
• Relative afferent pupillary defect (RAPD) or decreased direct pupillary reflex 1, 2
• Increased intraocular pressure measured by tonometry 1, 2
• Ophthalmoplegia or restricted extraocular movements 1, 2
• Conjunctival chemosis and subconjunctival hemorrhage 1
• Diplopia when extraocular movements are preserved 1

Critical Examination Components

Perform the following assessments immediately upon suspicion:

• Visual acuity testing to establish baseline and detect deterioration 3
• Pupillary examination specifically looking for RAPD 3, 1
• Intraocular pressure measurement using tonometry 3
• Exophthalmometry to quantify proptosis if equipment available 3
• Forced duction testing to distinguish mechanical restriction from nerve paresis 3
• Confrontational visual field testing 3

Imaging Strategy

CT orbit without contrast with thin cuts and multiplanar reconstructions is the imaging modality of choice when time permits, but imaging should never delay emergency decompression if clinical signs indicate orbital compartment syndrome. 4

When to Image

• CT is appropriate when the diagnosis is uncertain or the patient is stable without progressive vision loss 2
• CT has 94.9% sensitivity for detecting orbital fractures and associated hemorrhage 4
• Thin-section orbital CT identifies undisplaced fractures that commonly cause retrobulbar hematoma 2

When NOT to Image

• Do not obtain imaging if there are clear clinical signs of orbital compartment syndrome with vision loss—proceed directly to lateral canthotomy and cantholysis 1
• The procedure can be performed in the emergency room without prior imaging 1

MRI Considerations

• MRI is absolutely contraindicated if metallic foreign body is suspected due to risk of object movement 4
• MRI provides superior soft tissue detail but is inappropriate in the acute trauma setting 3

Emergency Intervention Criteria

Immediate lateral canthotomy with cantholysis is indicated when any of the following are present:

• Progressive vision loss 1, 5
• RAPD development 1
• Intraocular pressure elevation with clinical signs of optic nerve compression 1, 5
• No response to initial medical management 5

Treatment Algorithm

1. Recognize clinical signs of orbital compartment syndrome (proptosis, vision loss, RAPD, elevated IOP) 1
2. Perform lateral canthotomy and cantholysis immediately in the emergency department—this can be done by an ophthalmologist without imaging 1
3. Administer systemic corticosteroids as supportive therapy 1
4. If canthotomy/cantholysis fails to adequately decompress the orbit, proceed to surgical orbital decompression 1, 5

Surgical Decompression Options

When canthotomy and cantholysis are insufficient:

• Pterional orbital decompression provides maximal decompression and direct access to damaged structures 6
• Transantral approaches (ethmoidectomy, sphenoidectomy) are alternative options 5
• Mean delay between trauma and decompression in successful cases was 70 hours, but earlier intervention yields better outcomes 6

Critical Clinical Pitfalls

The most important pitfall is delaying treatment for imaging. Because reconstruction of cantholysis is generally uncomplicated, perform the procedure when retrobulbar hematoma is suspected rather than risk permanent vision loss. 1

Key Distinctions

• CT-diagnosed retrobulbar hematoma without clinical signs does not predict orbital compartment syndrome—in one study, only 1.1% of CT-documented hematomas developed compartment syndrome requiring intervention 7
• Clinical diagnosis drives treatment, not radiographic findings alone 7
• Retrobulbar hematoma occurs in 32% of orbital fractures on CT, but the vast majority do not require emergency decompression 7

Associated Findings Requiring Attention

• Bradycardia, nausea, vomiting, or loss of consciousness may indicate entrapped muscle causing oculocardiac reflex, which requires urgent medical and surgical intervention 3
• Check vital signs for bradycardia or heart block in all orbital trauma patients 3

Prognosis and Timing

• Immediate detection and treatment is mandatory for acceptable visual outcomes 6
• Visual acuity improved or remained normal in 60% of patients treated with decompression, but outcomes correlate directly with time to intervention 6
• Any delay between symptom onset and treatment significantly affects functional recovery 2