Risk factors for recurrence of postoperative trichiasis: implications for trachoma blindness prevention.

BACKGROUND Trachoma is the leading worldwide cause of preventable blindness. Surgery can alleviate trachomatous trichiasis (TT), the blinding sequelae of trachoma, but recurrence rates are high. OBJECTIVE To investigate risk factors for TT recurrence. METHODS We conducted a prospective case-control cohort study in Nepal that included patients with TT who were undergoing bilamellar tarsal-rotation surgery and control subjects who have scarring but no TT. Conjunctivae were graded for trachoma and swabbed to detect Chlamydia trachomatis by in-house and commercial (Roche Amplicor; Roche Diagnostics Corp, Indianapolis, Ind)-polymerase chain reaction. Univariate and multivariate analyses were performed for associations with chlamydiae and other risk factors. RESULTS Postoperative TT recurrence rates were 11.1% (4 cases) at 6 months and 25.0% (11 cases) at 12 months while no controls developed TT. Significantly, 5 (45.5%) of 11 patients with TT recurrences at 12 months had chlamydial infection at baseline (odds ratio, 6.0; 95% confidence interval, 1.5-24.3; P =.01), 8 (72.7%) at 6 months (odds ratio, 28; 95% confidence interval, 4.3-181.0; P <.001), and 9 (81.8%) at 12 months (odds ratio, 48; 95% confidence interval, 7.5-302.6; P =.00). No controls were infected during this time. Active trachoma and the baseline number of eyelashes touching the globe were also risk factors for TT recurrence. MAIN OUTCOME MEASURES The outcome variable was TT recurrence at 6 and 12 months. CONCLUSION To our knowledge, this is the first study to demonstrate that chlamydial infection at the time of surgery and at follow-up is a significant risk factor for postoperative TT recurrence.