The Utility of Preoperative Phenylephrine Testing in Müller Muscle Conjunctival Resection Surgery for Involutional Ptosis.

Purpose: Phenylephrine testing prior to Müller muscle conjunctival resection has traditionally been used to predict postoperative outcomes. The purpose of this study is to determine if preoperative phenylephrine testing impacts postoperative changes in eyelid position.

Methods: In this multicenter cross-sectional cohort study, 270 eyelids of participants with involutional ptosis and levator function >12 mm who underwent Müller muscle conjunctival resection were divided into 2 comparison groups. Participants who had preoperative phenylephrine testing served as the control group and those who did not were the study group. The primary outcome measure was postoperative marginal reflex distance from the upper eyelid margin (marginal reflex distance 1 [MRD1]) at the latest follow-up visit. Secondary outcomes included change in MRD1, reoperation rate, and predictive capacity of preoperative phenylephrine testing.

Results: Of the 270 eyelids that underwent Müller muscle conjunctival resection, 116 eyelids served as controls and 154 were in the study group. Mean age of participants was 62.6 years. Levator function, resection length, preoperative MRD1, change in MRD1, and latest postoperative MRD1 measures when compared in the control and study groups demonstrated no significance (p > 0.05) via 2-tailed t-test. Postoperative MRD1 was correctly predicted within 1 mm for 60.2% of eyelids that underwent preoperative phenylephrine testing.

Conclusions: Preoperative phenylephrine testing does not significantly predict postoperative eyelid elevation following Müller muscle conjunctival resection. Surgeons may thereby reassess the utility of preoperative phenylephrine testing given the lack of influence on surgical outcomes.