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Two patients with “black eyes” sustained in altercations (one black eye each). In both patients, the globe was intact. Visual acuity and extra-ocular movements were normal.

  • What are the radiographic findings in these patients?
  • (Figures 1 and 2)

In both of these patients, air is seen within the orbit—orbital emphysema. It appears as a radiolucent (dark) area in the superior portion of the right orbit just below the superior orbital rim (Figures 1 and 2). This is caused by a fracture through one of the walls of the orbit into an adjacent air-filled sinus. The fracture is either through the orbital floor into the maxillary sinus, or the medial orbital wall (lamina papyracea) into the ethmoid air cells. Orbital emphysema is one of the findings of a “blow-out” fracture, although it is not unique to that fracture.

A “blow-out” fracture occurs when the anterior orbit sustains an impact by an object of larger diameter than the orbit itself, e.g., a baseball or a fist. The blow causes increased intraorbital pressure fracturing its weakest part (the orbital floor or medial orbital wall) and not the globe itself (Figure 3). However, given this mechanism of injury, there is a high incidence of ocular injury (hyphema, vitreous hemorrhage, retinal detachment). An alternative mechanism of injury is a blow to the inferior orbital rim that causes buckling and a fracture of the orbital floor.

Figure 3

Blowout fracture of the orbital floor.

The fracture can cause entrapment of the inferior rectus muscle and injury to the infraorbital nerve.

[From Scaletta TA, Schaider JJ: Emergent Management of Trauma, McGraw-Hill, 1996, with permission.]

Radiographic signs of a blow-out fracture include soft tissue changes, which are frequently more easily seen than the fracture itself (Table 1). These soft tissue signs include overlying soft tissue swelling, a maxillary sinus opacification or air/fluid level, and orbital emphysema.

Table 1 Radiographic Signs of a Blow-Out Fracture

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