Keratoconus in Northern Tanzania: A hospital-based prevalence and clinical profile study

Background: Keratoconus (KC), a progressive, corneal, ectatic disease varies in prevalence globally. Differences and similarities in KC prevalence have been observed, and despite clinicians anecdotally reporting many KC cases, no empirical evidence of KC prevalence in Tanzania exists. Aim: This study aimed to determine the KC prevalence and demographic and clinical profiles of patients attending a tertiary hospital. Setting: The study was conducted at the Kilimanjaro Christian Medical Centre in Tanzania. Methods: The study applied a quantitative, retrospective study design whereby identified data were extracted from clinical records of patients aged 12 years – 45 years, presenting with corneal abnormalities, between the years 2016 and 2020. Statistical Package for Social Sciences was used for data analysis. Results: Of the 140 523 presenting patients, 1089 (0.77%) had corneal abnormalities, among whom KC prevalence was 10.0%. Patients were more likely to be men (odds ratio [OR]:1.5; P = 0.033) referred from lower-level clinics (OR:2.4; P ≤ 0.001) and residing in the Arusha region (OR:1.8; P = 0.012). Clinically, KC patients were more likely than non-KC to have vernal keratoconjunctivitis (VKC) (OR:3.8; P ≤ 0.001) and ocular allergies (OR:1.6; P = 0.028); be astigmatic (OR:6.5; P = 0.001) and myopic (OR:2.5; P = 0.001). Conclusion: The prevalence of KC among patients with corneal abnormalities is high, with significant predominance in patients with myopia, astigmatism and VKC. Data quality revealed a need for KC clinical guidelines, improved record keeping. Contribution: First study providing empirical KC data to guide improved patient care planning in Kilimanjaro.