Prevalence and predictors of Hering’s response in Müller’s muscle-conjunctival resection
Authors: Charlotte Lussier 1, Victoria C. Leung2, Jessica El-Khazen Dupuis1, Davin C. Ashraf3, Oluwatobi O. Idowu3, Erika Massicotte1, Reza M. Vagefi3, Robert C. Kersten3, Evan Kalin-Hajdu1. 1Université de Montréal, 2William Osler Health System, 3University of California, San Francisco.
Author Disclosures: C. Lussier: None. V.C. Leung: None. J. El-Khazen Dupuis: None. D.C. Ashraf: None. O.O. Idowu: None. E. Massicotte: None. R.M. Vagefi: None. R.C. Kersten: None. E. Kalin-Hajdu: None.
Abstract Body:
Purpose: "Determine the prevalence and predictors of Hering’s response following Muller's Muscle-Conjunctival Resection (MMCR)."
Study Design: "Seventy-five consecutive patients undergoing unilateral MMCR were recruited in this prospective, multicenter, cohort study."
Methods: "Margin-reflex distance-1 (MRD1) of both eyelids was recorded preoperatively and postoperatively. One hundred forty-five variables were investigated as potential predictors of a late postoperative (≥3 months) Hering’s response using regression analyses. Main outcome measures were Hering’s response (≥0.5 mm descent of the unoperated eyelid from baseline), and a clinically relevant Hering’s response (descent of the unoperated from baseline to a MRD1 2.0 mm, or descent from baseline such that the MRD1 of the unoperated eyelid became >1 mm lower than the operated eyelid)."
Results: "Twenty-four (32.0%) patients had a late postoperative Hering’s response, but only 6 (8.0%) responses were clinically relevant. A Hering’s response at the immediate (OR 16.24, p=0.02) and 1-week postoperative (OR 8.94, p=0.04) timepoints predicted a late postoperative response. However, the presence (OR 7.84, p=0.07) and amplitude (OR 8.13, p=0.06) of a preoperative phenylephrine Hering’s response did not predict a late postoperative response. Of the 10 patients with a clinically relevant phenylephrine Hering’s response, only 1 demonstrated a clinically relevant response late postoperatively."
Conclusions: "Unilateral MMCR induces a clinically relevant Hering’s response in 8% of patients. A preoperative phenylephrine Hering’s response does not predict a late postoperative Hering’s response. Therefore, when unilateral phenylephrine testing unmasks contralateral blepharoptosis, only the side with blepharoptosis at baseline should be operated."
