The impact of modified incision height and surgical procedure on trichiasis surgery outcomes: Results of the maximizing trichiasis surgery success (MTSS) randomized trial

Abstract

Background Poor surgical outcomes remain a problem in trachoma-endemic countries working to reach elimination thresholds. Methods to improve outcomes could positively impact programmatic success. Methods This parallel, three-armed clinical trial conducted in Ethiopia randomized individuals with previously unoperated trachomatous trichiasis (TT) to receive surgery utilizing one of three approaches: bilamellar tarsal rotation with a 3 mm incision height (BLTR-3), BLTR with 5 mm incision height (BLTR-5) and posterior lamellar tarsal rotation (PLTR). We followed participants for one year. The primary outcome was post-operative trichiasis (PTT). Secondary outcomes were eyelid contour abnormalities (ECA) and pyogenic granulomata. Findings We randomized and operated on 4,914 individuals with previously unoperated TT (6,940 eyes). Primary analyses include 6,815 eyes with follow-up. Overall, 1,149 (16.9%) eyes developed PTT. The risk difference for PTT was minimal comparing BLTR-3 and PLTR (adjusted risk difference [aRD] 1.8% (98.3%CI:-0.5–4.2%)), but significantly higher for BLTR-5 surgeries compared to BLTR-3 (aRD: 6.7% (3.9–9.4%)) and PLTR (aRD: 8.6% (5.9–11.3%)). BLTR-5 had the lowest ECA (6.1% versus 9.6% BLTR-3, 11.2% PLTR) and granuloma rates (5.2% versus 6.5% BLTR-3 and 7.5% PLTR). One eyelid operated with PLTR experienced an eyelid margin division; four BLTR-3 and eight BLTR-5 eyelids experienced excessive bleeding. Interpretation We do not recommend modifying the BLTR incision height of 3 mm. Overall, we did not find a significant difference in PTT between BLTR-3 and PLTR in terms of PTT or ECA.