Nontraumatic orbital hemorrhage.

Nontraumatic orbital hemorrhage (NTOH) is uncommon. I summarize the published reports of NTOH and offer a classification based on anatomic and etiologic factors. Anatomic patterns of NTOH include diffuse intraorbital hemorrhage, "encysted" hemorrhage (hematic cyst), subperiosteal hemorrhage, hemorrhage in relation to extraocular muscles, and hemorrhage in relation to orbital floor implants. Etiologic factors include vascular malformations and lesions, increased venous pressure, bleeding disorders, infection and inflammation, and neoplastic and nonneoplastic orbital lesions. The majority of NTOH patients can be managed conservatively, but some will have visual compromise and may require operative intervention. Some will suffer permanent visual loss, but a large majority have a good visual outcome.