Prevalence, Characteristics and Evolution of Mpox-Related Ophthalmic Disease: A Prospective Cohort Study in South-Kivu, Democratic Republic of the Congo (MBOTE-EYE)

Abstract Background Mpox-related ophthalmic disease (MPOXROD) ranges from mild conjunctivitis to sight-threatening keratitis, however, data based on systematic ophthalmological assessment are scarce. We aimed to characterise the prevalence, features, and temporal evolution of MPOXROD during a clade Ib mpox outbreak. Methods We conducted MBOTE-EYE, a prospective ophthalmological sub-study, nested within a clinical characterisation cohort in Kamituga, South-Kivu, Democratic Republic of the Congo. All hospitalised patients with mpox confirmed by PCR in the prior 48 hours were eligible. Participants underwent comprehensive ophthalmological examination at enrolment, discharge, and days 29 and 59 post-diagnosis. Conjunctival swabs were collected for monkeypox virus PCR testing. MPOXROD was defined as conjunctivitis, scleritis, keratitis, uveitis, or optic nerve involvement. Risk factors were assessed using mixed-effects Poisson regression. Findings Between 28 October 2024 and 30 June 2025, 310 participants were enrolled (median age 14 years, IQR 2.5-25.0; 53.5% female, n=166/310). At enrolment, conjunctivitis was present in 36.1% (95% CI 31.0–41.6%, n=112/310), keratitis in 7.7% (95% CI 5.3–11.3%), and anterior uveitis in 0.6% (95% CI 0.2–2.3%). Overall, 43.2% (95% CI 37.8–48.8%) developed MPOXROD during follow-up, most often bilaterally. Visual acuity