Keratoconus in Africa: A systematic review and meta‐analysis

Abstract Purpose The aim of this review is to evaluate the prevalence of and factors associated with keratoconus in Africa. Method A systematic online literature search was conducted for articles on keratoconus in Africa. Meta‐analysis was performed to estimate the prevalence of keratoconus in Africa. The Freeman‐Tukey double arcsine transformation was used to minimize the effects of studies with extremely high or low prevalence estimates on the overall pooled estimates. Leave‐one‐out sensitivity analysis was used to assess the robustness of the pooled effects and potential outliers. Meta‐regression was performed to explore associations between keratoconus, gender and age. Results Twelve studies were included in the review; 5 from Egypt, 2 from South Africa, 2 from Kenya, 1 from Sudan, 1 from Ghana and 1 from Nigeria. Two studies were conducted in allergic conjunctivitis patients, 4 in keratoconus patients, 1 in contact lens service seekers, 1 in pre‐LASIK patients, 1 in refractive patients and 1 in a student population. Eight studies were included in the meta‐analysis. The overall prevalence estimate of keratoconus in Africa was 7.9% (95% CI: 2.5%–16.0%). The prevalence of keratoconus among males and females in Africa was estimated to be 9.3% (95% CI: 2.5%–19.5%) and 5.8% (95% CI: 1.5%–12.7%) respectively. The estimated prevalence of unilateral and bilateral keratoconus was 2.6% (95% CI: 0.4%–6.5%) and 5.8% (95% CI: 1.6%–12.3%), respectively. The estimated prevalence of mild keratoconus was 2.2% (95% CI: 0.7%–4.7%), moderate keratoconus was 3.5% (95% CI: 0.0%–11.8%) and severe keratoconus was 4.0% (95% CI: 0.0%–19.6%). There was no significant association between gender and the prevalence of keratoconus in Africa ( p = 0.63), and age and the prevalence of keratoconus in Africa ( p = 0.78). Conclusion The estimated prevalence of keratoconus reported here is higher than prevalence values reported in other meta‐analyses or different geographical locations. This is mainly because studies included in this meta‐analysis were either conducted on a cohort at high risk of keratoconus or a population with high possibility of finding keratoconus patients. There is a dearth of well‐designed population‐based studies on keratoconus in Africa, resulting in a lack of epidemiological information. This highlights the urgent need for research on keratoconus in Africa.