Superior rectus-levator synkinesis - A previously unrecognized cause of failure of ptosis surgery

Purpose: To describe a previously unreported type of ptosis associated with abnormal synkinesis between the superior rectus muscle and the levator pal pebrae superioris. Design: Retrospective noncomparative case series. Participants: Seven cases with congenital or longstanding unilateral ptosis presenting to a regional, tertiary referral, oculoplastic service. Six of these cases were seen within a period of 2 years. Methods: Detailed observations of eyelid, ocular, and pupil movements of bo th eyes were performed before the planning of ptosis surgery anterior levat or resection. Main Outcome Measures: Magnitude of ptosis and its variation with the posit ion of gaze. Results: Ptosis present in the primary position disappeared or markedly red uced with upgaze so that measurements of levator function were apparently n ormal. Close examination of the relative movement of the eyelids revealed e vidence of superior rectus to levator synkinesis occurring during upgaze, I n three cases the synkinesis was recognized only after failed ptosis surger y. Once recognized, two of these cases underwent further surgery with an ex cellent result. Three other patients all had successful surgery. Conclusions Superior rectus to levator synkinesis may be easily overlooked if eyelid elevation in upgaze is ascribed to normal levator function rather than a synkinetic movement. We draw attention to the importance of identif ying this relatively common condition to plan appropriate ptosis surgery. T he lack of levator muscle tone in the primary position of gaze means that a n augmented resection of the levator muscle should be performed. Ophthalmol ogy 2000;107:1975-1981 (C) 2000 by the American Academy of Ophthalmology.