Retinal Vein Occlusion in Sub Saharan Africa: A Systematic Review and Meta-analysis

Background: Retinal vein occlusion (RVO) is a very common retinal vascular disorder and a significant cause of visual loss worldwide. However, the burden, proportion of subtypes, and risk factors associated with RVO in Sub-Saharan Africa (SSA) remain poorly explored and undefined. This systematic review and meta-analysis were conducted to assess the prevalence of RVO in Sub-Saharan Africa and its subtypes, risk factors, and presentation. Methods : A systematic search was conducted on PubMed/MEDLINE, African Journals Online, and Google Scholar for observational studies featuring RVO prevalence data published since January 2000 until October 2025. Selection of observational studies was performed in accordance with the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement 2020. Random-effects meta-analysis methods were used in obtaining prevalence rates, with heterogeneity tested with Cochran’s Q test and degree of heterogeneity determined with I² statistics. Funnel plots and regression test through Egger’s test were done to test publication bias. Results: Eight studies from five SSA countries (Nigeria, Liberia, Cameroon, Democratic Republic of Congo, and Benin) with a cumulative total of 158,940 participants were found to satisfy the criteria. RVO prevalence varied from 0.03% in general ophthalmology clinics to 10.8% among tertiary referral centers for retinal diseases. Overall, The Pooled prevalence of RVO among SSA countries was found to be 0.8% (95% CI = 0.2%–3.1%) , with a degree of heterogeneity of 97.9% (p < 0.001 Central retinal vein occlusion (CRVO) was common in studies from Nigeria (58% - 74%), Liberia (60%), and Cameroon (55%) , while branch retinal vein occlusion (BRVO) was found more frequently in Democratic Republic of Congo (69.2%). Benin reported almost equal incidents of CRVO and BRVO (50% each). The prevalent risk factor was systemic hypertension, followed by diabetes mellitus , while glaucoma was identified as the dominant eye complication. Visual acuities at presentation were poor in all studies. There was no evidence of publication bias (Egger's test, p ≈ 0.20). Conclusion : RVO is rare in general ophthalmic referrals in SSA but presents an important proportion in retina referrals. RVO demonstrates distinct links with systemic vascular risk factors, thus emphasizing the importance of comprehensive cardiovascular and ophthalmological management, as well as population-based epidemiological studies, in SSA.