Muller's Muscle-conjunctival Resection Procedure in the Treatment of Ptosis in Horner's Syndrome

Abstract

The predictability of the phenylephrine test and the efficacy of the Muller's muscle-conjunctival resection procedure in the management of blepharoptosis in six cases of Horner's syndrome were assessed. Before phenylephrine testing or surgery, an average of 2.3 mm of ptosis was present. Topical phenylephrine elevated upper lids an average of 2.2 mm. The amount of elevation produced by the phenylephrine guided the amount of Muller's muscle and conjunctiva resected. Postoperative upper lid levels were exactly symmetrical in five of six patients. In one patient the previously ptotic lid was 0.5 mm higher than the contralateral lid. Even though Muller's muscle is rendered nonfunctional in Horner's syndrome by denervation, the Muller's muscle-conjunctival resection procedure proved to be a very effective method of treating ptosis in this setting. Our findings imply that the mechanism by which this procedure alleviates ptosis is independent of active contraction of Muller's muscle.