Photo Rounds

Direct or true blow-out fracture of the orbital floor . A 17-year-old man presented with a 3-day history of double vision on upward gaze after having been struck in the right eye with a clenched fist. A direct blow-out fracture occurs when all the energy that causes the injury is transferred through the globe. The periorbital ecchymosis, edema, subconjunctival hemorrhage, and paresis on upward gaze (patient is shown with upward gaze) are suggestive of an orbital floor fracture with entrapment of orbital contents. Other signs of orbital floor fracture include decreased visual acuity, epistaxis, and paresthesias of the distribution of the infraorbital nerve. A coronal computerized tomography (CT) of the orbits demonstrates blood in the right maxillary sinus and orbital contents extruding through a defect in the orbital floor. A CT of the orbits is indicated when there is evidence of entrapment of orbital contents on examination (paresis on upward gaze). (L.S.)