Uncovering ocular pseudomyasthenia.

A 61-year-old woman who presented with unilateral ptosis and subsequently a lateral rectus weakness was followed for 2.5 years with the diagnosis of ocular myasthenia. Signs then developed that led to the discovery of a cavernous sinus meningioma. When ruling out ocular myasthenia, the importance of checking for diminished corneal sensation, an anisocoria that increases in the light, and aberrant regeneration of the third cranial nerve is pointed out.