Iris atrophy in patients with newly diagnosed multibacillary leprosy: at diagnosis, during and after completion of multidrug treatment.

Abstract

To describe the prevalence and incidence of iris atrophy in patients with multibacillary (MB) leprosy. Prospective longitudinal cohort study. 301 newly diagnosed patients with MB leprosy were followed up during the 2 years of treatment with multidrug therapy (MDT) and for a further 5 years with biannual ocular examinations. Incidence of iris atrophy was calculated as the number of patients with iris atrophy per person-year (PY) of follow-up among those who did not have iris atrophy at baseline. Stepwise multiple regression confirmed the presence of specific associations of demographic and clinical characteristics (p<0.05) with iris atrophy, detected by univariate analysis. Iris atrophy was present in 6 (2%) patients at enrolment. During MDT, with 445 PYs of follow-up, 9 patients developed iris atrophy (IR 0.02, 95% CI 0.01 to 0.04) that was associated with cataract (HR 15.13, 95% CI 3.71 to 61.79, p<0.001) and corneal opacities (HR 6.83, 95% CI 1.62 to 28.8, p = 0.009). After MDT, with 2005 PYs of follow-up, 60 patients developed iris atrophy (IR 0.03, 95% CI 0.023 to 0.039) that was associated with age (per decade; HR 1.40, 95% CI 1.10 to 1.78, p = 0.006), skin smear positivity (HR 3.50, 95% CI 1.33 to 9.24, p = 0.011), cataract (HR 3.66, 95% CI 1.85 to 7.25, p<0.001), keratic precipitates (HR 2.76, 95% CI 1.02 to 7.47, p = 0.046) and corneal opacity (HR 3.95, 95% CI 1.86 to 8.38, p<0.001). Iris atrophy continues to develop in 3% of patients with MB leprosy every year after they complete a 2-year course of MDT, and is associated with age, increasing loads of mycobacteria, subclinical inflammation, cataract and corneal opacity.