Prevalence of the Burden of Diseases Causing Visual Impairment and Blindness in South Africa in the Period 2010–2020: A Systematic Scoping Review and Meta-Analysis

Abstract

The prevalence of visual impairment (VI) continues to rise, despite efforts to reduce it. The burden of disease negatively impacts the quality of life, education opportunities, and other developments in various communities. Henceforth, this study aimed to determine and quantify the major causes of VI in South Africa, to ensure accurate interventions in addressing them and to reduce the burden of ocular disease in that context. A systematic scoping review was conducted to map evidence on VI and ocular diseases, using the PRISMA-P guidelines. English studies were searched for on PubMed, Google Scholar, and EBSCOhost using various search terms. The eligible articles underwent screening and ultimately data extraction to identify major causes of VI in South Africa. A meta-analysis further resulted in pooled prevalence estimates (PPE) using the Inverse Variance Heterogeneity (IVhet) model. Of the 13,527 studies screened at three levels, 10 studies met the inclusion criteria for the final review; however, 9 studies were eligible for quality assessment performed by two independent reviewers. The quality index for the included studies was 71.1%. The prevalence of VI was 2% for blindness and 12% for moderate and severe visual impairment (MSVI). Pooled prevalence identified uncorrected refractive error (URE) (43%), cataract (28%), glaucoma (7%), and diabetic retinopathy (4%) as major causes of MSVI. The leading causes of blindness were untreated cataracts (54%), glaucoma (17%), and diabetic retinopathy (57%). Ocular diseases causing VI are avoidable and similar to those of low-to-middle income countries. MSVI were caused by URE, cataract, glaucoma, and diabetic retinopathy. Blindness was mainly caused by cataracts, glaucoma, and diabetic retinopathy. A strategic plan to manage these conditions would largely reduce the burden of VI in the country. Early screenings and interventions to maximize care at primary health levels would decrease the burden of avoidable blindness in the country significantly.