Abstract
Brown syndrome is characterised by impaired supraduction worse in adduction due to a restricted superior oblique tendon passing through the trochlea. A few reports have previously described Brown syndrome after upper eyelid surgery, including blepharoplasty and ptosis repair. The authors describe two additional cases of Brown syndrome following ptosis repair. The first case is a 65-year-old woman with new-onset vertical binocular diplopia following bilateral levator advancement surgery. Ocular motility examination demonstrated moderate impairment of elevation in adduction. The second case is a 35-year-old woman who presented with new-onset intermittent binocular diplopia following right upper lid ptosis repair. Examination revealed large vertical fusional amplitudes and a large left intermittent hyperphoria in an alignment pattern consistent with Brown syndrome. Despite presenting after surgery, these cases differ in mechanism. The first case likely occurred due to intraoperative impairment of the superior oblique tendon sheath or trochlea, whereas the second case represented an unmasking of a long-standing, previous vertical strabismus that was consistent with a Brown syndrome pattern.