DESCRIPTION 
- Defined as an orbital floor fracture without orbital rim involvement
- Results from sudden blunt trauma to the globe:
- Typically caused by the force of a projectile > half the size of the fist
- Force transmitted through the noncompressible structures of the globe to the weakest structural point: The orbital floor
- Transmitted force "blows out" or fractures the orbital floor.
- Orbital floor serves as roof to air-filled maxillary and ethmoid sinuses:
- Communication between the spaces results in orbital emphysema.
- Orbit contains fat, which holds the globe in place:
- Orbital floor fracture may result in herniation of the fat on the inferior orbital surface into the maxillary or ethmoid sinuses.
- Leads to enophthalmos owing to orbital volume loss and sinus congestion; fluid collection may occur secondary to edema and bleeding.
- Infraorbital nerve runs through the bony canal 3 mm below the orbital floor:
- Injury may result in hypoesthesia of the ipsilateral cheek and upper lip.
- To distinguish facial hypoesthesia related to local swelling from nerve injury: Test for sensation on the ipsilateral gingiva, which is within the infraorbital nerve distribution.
- Inferior rectus and the inferior oblique muscle run along the orbital floor:
- Restriction of these extraocular muscles may occur because of entrapment within the fracture, contusion, or cranial nerve dysfunction.
- Typically manifests as diplopia on upward gaze
- Inability to elevate the affected eye normally on exam
- Medial rectus located above the ethmoid sinus:
- Less commonly entrapped
- Diplopia on ipsilateral lateral gaze
ETIOLOGY
Caused by a projectile which strikes the globe. The force is transmitted through the noncompressible structures of the globe to the weakest structural point: the orbital floor resulting in a blow out fracture.
Pediatric Considerations
- Orbital roof fractures with associated CNS injuries more common in children
- Orbital floor fractures: Unlikely before 7 yr of age:
- Orbital floor is not as weak a point in the orbit due to lack of pneumatization of the paranasal sinuses.
- Unfortunately fractures can occur in children and may result in unrecognized entrapment of the rectus muscle labeled the "white-eyed" fracture:
- These children may present with marked nausea, vomiting, headache, and irritability suggestive of a head injury that commonly distracts from the true diagnosis.
[Outline]
SIGNS AND SYMPTOMS
- Periorbital tenderness, swelling, and ecchymosis
- Impaired ocular mobility or diplopia:
- Restricted upward gaze owing to inferior rectus entrapment
- Restricted ipsilateral lateral gaze with medial rectus entrapment
- Infraorbital hypoesthesia:
- Caused by compression/contusion of infraorbital nerve
- May extend to upper lip
- Enophthalmos:
- Globe set back owing to orbital fat displaced through fracture
- Periorbital emphysema:
- From the ethmoid or maxillary sinus
- Epistaxis
- Normal visual acuity:
- If not, consider more extensive injuries
- No orbital rim step off
Associated Severe Injuries
- Ocular injuries:
- Ruptured globe:
- Incidence up to 30% of blow-out fractures
- Ophthalmologic emergency
- Retrobulbar hemorrhage
- Emphysematous optic nerve compression
- Cervical spine or intracranial injuries
- Commonly associated injuries:
- Less common:
- Associated fractures:
- Late complications:
- Sinusitis
- Orbital infection
- Permanent restriction of extraocular movement
- Enophthalmos
History
Struck in the eye with a projectile. Paintball, handball, racquetball, baseball, rock, or possibly fist. Larger-sized projectiles will likely be blocked by the orbital rim. Seen frequently after MVCs which are the most common cause of maxillofacial trauma.
Physical Exam
- Thorough ophthalmologic exam:
- Palpate bony structures of the orbit for evidence of step off.
- Careful attention not to place pressure on the globe until ruptured globe excluded:
- Desmarres lid retractors may be necessary to evaluate the eye with swollen lid.
- Document pupillary response
- Visual acuity (should not be affected):
- Handheld visual acuity Rosenbaum card is most useful with injuries.
- Test extraocular movements for disconjugate gaze or diplopia.
- Test sensation in inferior orbital nerve distribution.
- Examine lid and adnexa:
- Orbital emphysema may be present.
- Slit-lamp and fundoscopic exam to identify associated injuries.
- Full physical exam to identify associated injuries and neurologic impairment.
DIAGNOSIS TESTS & INTERPRETATION
Lab
- Preoperative lab studies if indicated
- Pregnancy testing prior to radiography
Imaging
- If CT unavailable or contraindicated, plain radiographs will provide important information:
- Facial films
- Orbits
- Waters view and exaggerated Waters view:
- Classic "teardrop sign" illustrates herniated mass of orbital contents in the ipsilateral maxillary sinus.
- Opacification of or air–fluid level in the ipsilateral maxillary sinus (less specific)
- Orbital floor bony fracture
- Lucency in orbits consistent with orbital emphysema
- CT-preferred modality:
- Defines involved anatomy
- Obtain axial and coronal 1.5-mm cuts:
- Reconstruction of coronals not preferred but acceptable if positioning impossible
Diagnostic Procedures/Surgery
Forced duction test:
- Distinguishes nerve dysfunction from entrapment
- Topical anesthesia applied to the conjunctiva on the opposite side, and the globe is pulled away from the expected point of entrapment; if the globe is not mobile, the test is positive—defining physical entrapment.
Pediatric Considerations
- Orbital CT: Study of choice:
- Essential to identify entrapment early as long-term outcome will likely be affected if left undiagnosed:
- Early surgical intervention for entrapment may significantly improve outcome.
DIFFERENTIAL DIAGNOSIS
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PRE-HOSPITAL
- Metal protective eye shield if possible globe injury
- Place in supine position.
INITIAL STABILIZATION/THERAPY
Initial approach and immediate concerns:
- Assess for associated intracranial or cervical spine injuries.
- Rule out ruptured globe.
- Test visual acuity:
- Decreased visual acuity suggestive of associated with more extensive injuries
ED TREATMENT/PROCEDURES
- After globe rupture is excluded, apply cool compresses for the 1st 24–48 hr to decrease swelling to minimize or reverse herniation and avoid surgical intervention.
- Avoid Valsalva maneuvers and nose blowing to prevent compressive orbital emphysema.
- Prophylactic antibiotics to prevent infection
- Nasal decongestants if no contraindication
- Analgesics as needed
- Tetanus prophylaxis
MEDICATION
- Antibiotics are recommended prophylactically to prevent sinusitis and orbital cellulitis:
- Systemic corticosteroids have been advocated to speed up the resorption of edema in order to more accurately assess any muscle entrapment and orbital damage:
- Prednisone (60–80 mg/d) within 48 hr of the injury and continued for 5 days
- Nasal decongestants may be beneficial if not contraindicated:
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DISPOSITION
Admission Criteria
- Rarely indicated
- 85% resolve without surgical intervention.
- Consultation with facial trauma service in ED and consideration for admission if:
- 50% of floor fractured
- Diplopia or entrapment is identified
- Particularly in children
- Enophthalmos > 2 mm or more
Discharge Criteria
In most cases, observe for 10–14 days until swelling resolves, then follow up with facial trauma surgeon to determine need for surgical intervention.
FOLLOW-UP RECOMMENDATIONS
Symptoms should improve over time:
- If at any point patient develops increased swelling, tenderness, redness, or pain around the eye, they should return to ED for re-evaluation.
- If any visual disturbance, visual loss, or increased eye pain return to ED for re-evaluation.
[Outline]
- Alinasab B, Ryott M, Stjärne P. Still no reliable consensus in management of blow-out fracture. Injury. 2012;45:197–202.
- Cruz AA, Eichenberger GC. Epidemiology and management of orbital fractures. Curr Opin Ophthalmol. 2004;15(5):416–421.
- Gosau M, Schöneich M, Draenert FG, et al. Retrospective analysis of orbital floor fractures – complications, outcomes and review of the literature. Clin Oral Investig. 2011;15(3):305–313.
- Higashino T, Hirabayashi S, Eguchi T, et al. Straightforward factors for predicting the prognosis of blow-out fractures. J Craniofac Surg. 2011;22(4):1210–1214.
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