Ophthalmic presentations of cluster headache.

Cluster headache is frequently characterized by pain localized to the orbital area. There is often associated ipsilateral oculosympathetic paresis with varying degrees of blepharoptosis and miosis. The ophthalmologist is often confronted with such cases; however, the atypical presentations and the subtle clinical findings may obscure the diagnosis. As cluster headache is a benign condition, accurate recognition is essential to spare the patient potentially harmful diagnostic studies.