Effectiveness of An Intraoperative Lagophthalmos Formula for Levator Resection in Patients With Congenital Ptosis.

Abstract

To evaluate the effectiveness of an intraoperative lagophthalmos formula (IOLF) for levator resection in congenital ptosis and investigate the optimal preoperative conditions for IOLF application. This retrospective interventional cohort study evaluated 30 eyelids of 22 patients with congenital ptosis who underwent levator resection using the IOLF to calculate the extent of surgical correction under general anesthesia. Surgical success was defined as margin reflex distance-1 (MRD1)≥3mm in each eye and a difference of MRD1 1mm between the eyes at 6 months postoperatively. Logistic regression was performed to investigate the preoperative conditions associated with surgical success. Among 30 eyelids, 19 had good-to-fair levator function (LF) (≥5mm) and 11 had poor LF ( 4mm). The overall success rate was 90.0% (n=27/30), whereas the under-correction rate was 10.0% (n=3/30). The surgical success rate was 100% (n=19/19) in eyelids with LF ≥5mm and 72.7% (n=8/11) in eyelids with LF 4mm. Patients with preoperative MRD1≥0mm (versus MRD1<0mm, odds ratio=34.5, P =0.0098) or a combination of preoperative MRD1≥0mm and LF≥5mm (versus MRD1<0mm and LF 4mm, odds ratio=48.0, P =0.0124) more likely had successful surgical outcomes. Levator resection using the IOLF can provide satisfactory results for congenital ptosis regardless of LF. Preoperative MRD1≥0mm may be suitable for IOLF application, and the combination of preoperative MRD≥0mm and LF≥5mm may be the optimal preoperative condition for IOLF application.