Marcus Gunn jaw-winking phenomenon - A new supplemental test in the preoperative evaluation

Purpose: To introduce a new method for the evaluation of Marcus Gunn jaw-wi nking ptosis that more precisely defines the severity of blepharoptosis. Methods: A retrospective review of 16 consecutive patients with Marcus Gunn jaw-winking ptosis presenting to our institution between 1993 to 1999 was performed. The position of the affected eyelid was observed after applying a technique of jaw immobilization and disruption of fusion with temporary o cclusion of the ipsilateral side. Results. In patients presenting with mild to moderate Marcus Gunn jaw-winki ng, the majority (62.5%) demonstrated a positive test, uncovering complete or near complete ptosis. Test results were partially positive in 3 patients (18.8%) with increased but not complete ptosis and negative in 3 patients (18.8%) with no change in eyelid position. Conclusions. Blepharoptosis associated with Marcus Gunn jaw-winking phenome non is often more severe than found by conventional clinical evaluation. Th is finding may explain the frequent undercorrection and unpredictable resul ts following levator resection. In patients exhibiting a positive jaw-winki ng ptosis test, disappointing outcomes with levator resection may be avoide d by instead proceeding with a frontalis suspension with levator disinserti on as recommended for ptosis with severe jaw winking.