Müller Muscle Conjunctival Resection: A Prospective Multicenter Comparison of Eyelid Height at the Immediate, 1-Week, and 3-Month Postoperative Time Points

Purpose: The primary objective was to document change in postoperative marginal reflex distance-1 (MRD1) after Müller muscle conjunctival resection surgery. The secondary objective was to identify predictors of change in postoperative MRD1. Methods: A multicenter prospective cohort study was performed on patients consecutively recruited for Müller muscle conjunctival resection. MRD1 was measured immediately after Müller muscle conjunctival resection, at the 1-week postoperative visit, and the ≥3-month postoperative visit. MRD1 at the immediate and 1-week time points were compared with MRD1 ≥3 months using descriptive statistics. Predictors of change in MRD1 were analyzed using multivariate regression analysis. Results: A total of 150 patients (226 eyelids) were included. Regarding the immediate to ≥3-month interval, 53.8% of eyelids remained clinically similar (rise or fall ≤0.5 mm), 19.8% rose ≥1 mm, and 26.4% fell ≥1 mm. Regarding the 1-week to ≥3-month interval, 76.5% remained clinically similar, 17.3% rose ≥1 mm, and 6.2% fell ≥1 mm. No variable predicted change in MRD1 over either interval with both clinical and statistical significance. Conclusions: Immediate postoperative MRD1 is likely to reflect the late result in only 54% of cases. However, 1-week postoperative MRD1 is similar to the late result in 77% of cases and is highly unlikely (6%) to fall by the final visit. No variable significantly impacts change in postoperative MRD1.