Influence of the Phenylephrine Test in Outcomes of External Levator Advancement for Involutional Ptosis

Purpose: This study aims to evaluate the influence of preoperative phenylephrine testing on the surgical outcome of patients undergoing surgery for involutional ptosis by external levator advancement. Methods: This was an observational, monocentric, retrospective study. Fifty-one eyelids from 32 patients, who had surgery between January 2018 and May 2023, were included for analysis. Preoperative clinical examination data were collected. Evaluation was performed at 1 month postoperatively. Surgical success was defined by a postoperative margin reflex distance between 3 and 5 mm inclusive. Symmetry success was defined by a difference in margin reflex distance between the 2 upper eyelids of no more than 1 mm. Results: The surgical success rate was 86%. A positive preoperative phenylephrine test was significantly associated with a better surgical success rate ( p = 0.01), including on symmetry ( p = 0.01). The secondary outcomes, namely preoperative margin reflex distance, function of the upper eyelid levator muscle, and unilaterality of surgery, were not statistically associated with surgical outcome. Conclusions: The phenylephrine test is a predictive factor of surgical success in patients undergoing external levator advancement. Our study suggests that patients with a negative phenylephrine test should be overcorrected intraoperatively.