Which facial bone fracture is associated with diplopia (double vision) on upward gaze or vertical movements of the eyes?

Inferior Orbital Wall Fracture Causes Diplopia on Upward Gaze

The inferior orbital wall (orbital floor) fracture is associated with diplopia on upward gaze or vertical movements of the eyes. 1

Mechanism of Diplopia in Orbital Floor Fractures

• Orbital floor fractures can lead to entrapment of the inferior rectus muscle or orbital contents, restricting upward movement of the eye 1
• Incarceration of the inferior rectus muscle within a trap door fracture may rapidly result in ischemic injury of the muscle and subsequent restrictive strabismus 1
• In children, elastic, cancellous bone with resilient periosteum leads to trap door orbital fracture, which causes entrapment of the extraocular muscles or other orbital contents 1
• Even without direct muscle entrapment, significant fat or periorbital tissue entrapment can result in permanent strabismus 1

Clinical Presentation and Diagnosis

• Diplopia on upward gaze is statistically significantly associated with orbital floor fractures 2
• Other signs of orbital floor fractures include periorbital soft tissue swelling, ecchymosis, hyphemia, subconjunctival hemorrhage, and restriction of ocular movement 1
• Forced duction testing can help distinguish between restriction (positive test) and paresis (negative test) of the extraocular muscles 1
• CT imaging is considered the most useful imaging modality for evaluating orbital trauma and is the most accurate method for detecting fractures and muscle entrapment 1

Management Considerations

• Timing of surgical repair for orbital floor fractures depends on several factors:

  • Immediate repair is indicated for patients with CT evidence of an entrapped muscle or periorbital tissue associated with a nonresolving oculocardiac reflex 1
  • "White-eyed blow-out fracture" (a form of trap-door fracture with muscle entrapment and oculocardiac reflex seen in children) requires urgent repair 1
  • Symptomatic diplopia with positive forced ductions or entrapment on CT and minimal improvement over time is best repaired within 1-2 weeks 1
  • Large floor fractures, hypoglobus, and progressive infraorbital hypoesthesia are also best addressed within about 2 weeks 1

• Even with repair or observation of orbital fractures, diplopia can persist:

  • In one series of patients who underwent repair of orbital blowout fractures, 86% had diplopia preoperatively and 37% postoperatively 1
  • Early intervention for orbital floor fractures with muscle entrapment improves outcomes for diplopia 3
  • For patients without muscle entrapment, waiting 4-6 months after orbital trauma is advised as strabismus may resolve on its own 1

Pitfalls and Caveats

• Diplopia itself does not always imply extraocular muscle entrapment, as soft tissue swelling, hematoma, or nerve paresis can also lead to restricted ocular movement 1
• Vital signs should be monitored for bradycardia or heart block, along with symptoms of dizziness, nausea, vomiting, or loss of consciousness, which may indicate an entrapped muscle causing the oculocardiac reflex—a potentially life-threatening condition requiring immediate medical and surgical treatment 1
• Orbital fat entrapment can prove nearly as challenging as extraocular muscle entrapment, resulting in fibrotic and adhesion syndromes not readily relieved with dissection around the involved muscle 1
• Late correction of orbital fractures has poorer outcomes for diplopia compared to early intervention 4, 5