Sickle cell retinopathy in Africa: a systematic review and meta-analysis

Abstract

Sickle cell disease (SCD) is highly prevalent in Africa and is known for various systemic and ocular complications such as sickle cell retinopathy (SCR). Due to the potential for irreversible vision loss, understanding the burden of sickle cell retinopathy (SCR) in African populations is important. This systematic review and meta-analysis aimed to estimate the overall prevalence of SCR in Africa and to explore regional variation and associated factors. A detailed literature search was carried out on PubMed, Embase, Google Scholar, AJOL, and WHO Global Index Medicus (2000–2025) for observational studies that estimated the prevalence of SCR among patients with SCD from the African continent. Studies were included if they were cross-sectional surveys, cohort studies, and case series with well-defined numerator and denominator. The Joanna Briggs Institute (JBI) critical appraisal checklist was used for study quality assessment. A random-effects model with logit transformation was used for meta-analysis to estimate the prevalence. Heterogeneity was estimated with I2 statistic, τ2 statistic, Cochran Q test, and prediction intervals. A total of eleven studies from nine African countries involving 1,182 patients with sickle cell disease satisfied the inclusion criteria. The overall SCR prevalence was found to be 25.7% (95% CI: 21.9–29.9%), with a high degree of heterogeneity (I² = 94.7%). The 95% prediction interval ranged from 4% to 81%. Important differences in SCR prevalence were observed across geographic regions; for instance, SCR was least observed in West Africa (12%), while East Africa showed a moderate prevalence (23%), and other regions demonstrated much higher figures: Central Africa (45.4%), Southern Africa (53%), and Northern Africa (56%). Across the included studies, older age, male sex, and the HbSC genotype were the most commonly reported factors associated with a higher prevalence of sickle cell retinopathy. SCR represents a frequent ocular complication among Africans with SCD and occurs with a prevalence that approaches one-fourth of all patients. Such marked geographical variability may well be related to differences in genotype distribution and demographics and can be taken to underscore the imperative for routine fundoscopic screening and preventive programs for vision loss among Africans with this disease.