UNILATERAL CONGENITAL PTOSIS WITH IPSILATERAL SUPERIOR RECTUS MUSCLE OVERACTION

PURPOSE: Congenital ptosis may be accompanied by weakness of the ipsil ateral superior rectus muscle. We report the finding of a hypertropia of the ipsilateral eye in patients with isolated unilateral congenital ptosis that became manifest only in upgaze. METHODS: Seventy consecut ive patients with congenital ptosis were recalled and 58 reexamined. E xamination included assessment of visual acuities, palpebral apertures , levator muscle function, and an orthoptic examination. Particular at tention was paid to the assessment of upgaze. RESULTS: Thirty-eight pa tients had an isolated unilateral congenital ptosis. Four patients had bilateral ptosis, six had upgaze deficits, and ten others had a varie ty of other syndromes associated with ptosis. Seventeen of the 38 pati ents with isolated unilateral congenital ptosis were found to have an ipsilateral hypertropia on upgaze. The size of the vertical deviation varied from 5 to 30 prism diopters and, in the more severe cases, prod uced a cosmetic problem that became more noticeable after successful p tosis surgery. In one of these patients, a superior rectus muscle post erior fixation suture was effective in reducing the hypertropia. CONCL USION: Of a number of possible causes for the ipsilateral hypertropia in upgaze in patients with unilateral congenital ptosis that we observ ed, either a misdirection syndrome within the superior division of the oculomotor nerve or an exaggerated Bell's reflex is the most likely.