Exophthalmos

An abnormal anterior protrusion of one or both eyeballs beyond the orbital rim, and may be associated with exposure keratopathy, restricted extraocular motility, and optic neuropathy. Common causes are Graves' disease, orbital cellulitis, orbital abscess, trauma (retro-orbital hemorrhage), carotid-cavernous AV-fistula, and orbital tumors (hemangioma, leukemia, neuroblastoma, lymphoma, secondary metastases).