Neuroimaging is not necessarily required if the patient is female, has a history of previous episodes and/or migraines, and the dilated pupil is the only ocular finding. The dilated pupil will constrict to 1% pilocarpine, in contrast to a pharmacologically dilated pupil. Specifically, no ptosis or EOM involvement is found and the patient may report previous episodes. The dilated pupil is intermittent, lasting for hours to days, and is the only ocular finding. The size of your pupils is controlled by muscles in the coloured part of your eye (iris) and the amount of light reaching your eyes. A brain MRI and MRA were both negative.īenign episodic unilateral mydriasis is most commonly seen in women with a history of migraines. Dilated pupils are pupils that are larger than normal in size. She reported experiencing a migraine 24 hours after our visit and resolution of the dilation after 48 hours. The patient followed up in 3 days at our office and presented at that time with normal pupils (see the second photo). Given the otherwise normal examination and history of migraines, the patient was diagnosed with benign episodic unilateral mydriasis (BEUM). The attached photo shows the pupils at presentation.

The BVA was slightly decreased at distance OS (20/25) and near (J2). Examination was negative for a reverse APD, diplopia, EOM involvement, or ptosis. If youve ever had an eye examination, youve probably had your pupils dilated-when the doctor puts drops in your eyes and the pupil becomes larger than normal. Otherwise, the patient, who has a history of migraines, was asymptomatic including a lack of headache at the time of presentation. A few hours earlier the patient noted a loss of focusing ability and dilation in the left eye only. A 32-year-old Caucasian female was referred for a unilateral, dilated pupil.