Ocular and periocular pain.

Periocular pain may result from local pathology or be referred from distant sites. Ophthalmic examination will detect most local disease, although a careful search may be needed to determine the cause of subtle entities. Painful ophthalmoplegia results from a variety of neoplasms and inflammations, often in the area of the cavernous sinus. Cluster headache should be differentiated from more sinister causes of painful Horner's syndrome. Systemic diseases that cause periocular pain and migraine and other classic headache syndromes that may present with eye pain alone are also discussed.