Oculocardiac reflex in an adult with a trapdoor orbital floor fracture: case report, literature review, and differential diagnosis

Orbital floor blowout fractures can result in a variety of signs and symptoms depending on the severity of the bone defect. Large defects often result in enophthalmos and restriction of ocular movement; yet the timing of surgery can be delayed up to two weeks with good functional outcomes. In contrast, an orbital trapdoor defect with entrapment of the inferior rectus muscle usually elicits pain with marked restriction of the upward gaze and activation of the oculocardiac reflex without significant dystopia or enophthalmos. When autonomic cardiac derangement is diagnosed along with an orbital floor fracture, it has been suggested that the fracture should be treated immediately. Otherwise, it will result in continued hemodynamic instability and muscular injury and may require a second surgery. This article reports the management of an unusual presentation of a trapdoor blowout orbital floor fracture surgery with oculocardiac response in an adult, with emphasis on its pathophysiology, management, and differential diagnosis.