Intermittent mydriasis associated with carotid vascular occlusion.

PurposeTo describe two cases of stereotyped, intermittent, neurologically isolated, unilateral mydriasis in patients with a history of acquired internal carotid artery (ICA) occlusive disease on the ipsilateral side.PatientsTwo patients with intermittent mydriasis.MethodsCase Series.ResultsCase one: A 78-year-old man experienced 10 episodes of intermittent, unilateral, and painless mydriasis in the left eye and had 100% occlusion of the left ICA artery due to atherosclerotic disease. Case two: A 26-year-old woman with history of migraine developed new painless, intermittent episodes of unilateral mydriasis after sustaining chest trauma and was diagnosed with subsequent dissection and 65% occlusion of the ipsilateral ICA. Neither patient developed permanent anisocoria.ConclusionBenign episodic unilateral mydriasis (BEUM) typically presents in young women with a history of migraine. To our knowledge, these are the first cases of episodic, unilateral, neurologically isolated mydriasis associated with occlusive disease of the ICA in the English language ophthalmic literature. We hypothesize that transient dysfunction of the autonomic nervous system related to the ICA disease may account for the intermittent mydriatic episodes in these patients and we recommend consideration for imaging of the ICA in patients with atypical features for BEUM (for example, old age or males, non-isolated mydriasis, or recent trauma).