Prevalence and determinants of keratoconus in Kilimanjaro region: a population-based evaluation

The study aimed to determine the distribution and determinants of keratoconus (KC) among individuals aged 12–45 years in the Kilimanjaro region, where epidemiological data are currently lacking. A cross-sectional population-based screening was conducted between July 2024 and January 2025 among secondary schools, college and community members. Screening involved six steps: registration and visual acuity assessment, autokerato-refractometry, the Keratoconus Risk Investigative Survey (KRIS), retinoscopy, corneal topography, and counselling or referral. KC diagnosis and classification was based on a total weighted score ≥ 6–10 (scissor reflex, myopia >-5D, astigmatism ≤ 2.5D, Kmax > 46.5D, I-S > 1.4, steep K > 47D) and KC-suspect if score 2–5 including presence of scissor reflex and/or irregular astigmatism; and no KC if score < 2. Data were analyzed. using Statistical Package for Social Sciences (SPSS) version 26 and Stata version 14. A total of 2,354 participants (49.7% female, 50.3% male), the majority of whom were Black African adolescents, aged 12–19 years, were screened. The prevalence of KC was 1.2% (95% CI: 0.8–1.7), with a mean age of 20.7 ± 7.2 years. Univariate analysis showed associations between KC and male gender (OR = 2.6, p = 0.016), age 12–24 years (OR = 4.0, p = 0.001), eczema (OR = 33.7, p < 0.001), and asthma (OR = 5.5, p = 0.011). Multivariate analysis demonstrated that only eczema is significantly associated with KC. Overall, the findings indicate that KC is present at a clinically important level in the Kilimanjaro Region, particularly among adolescents and young adults, with eczema representing the strongest independent risk factor. The results support the implementation of targeted screening programs and strengthened referral pathways to facilitate early diagnosis and management of KC.