Orbital Fat Herniation Through Inferior Orbital Fissure and Persistent Diplopia Caused by Facial Trauma.

Orbital fat herniation is often accompanied by orbital floor fractures. Furthermore, herniation through the inferior orbital fissure (IOF) is rare, and its pathophysiology remains largely unknown. Here, the authors report a case of a patient with IOF herniation and diplopia caused by orbital trauma. The patient was a 58-year-old male who had undergone reduction of a left zygomatic fracture 15 years previously; however, reduction of the lateral orbital wall displacement was not performed at that time. The patient presented with refractory diplopia following a sports-related orbital injury. Although no new facial fractures occurred, an asymmetric IOF herniation was observed in the left orbital fissure, which caused persistent diplopia. Surgical repair of the orbital fat herniation was performed 46 days after injury. Two months after the surgery, the herniation of the orbital fat and diplopia completely disappeared. Surgery for an IOF herniation should be considered when ocular symptoms persist after orbital trauma.