A systematic review of dietary factors and predominant eye diseases in sub-Saharan Africa identifies key ocular nutritional evidence gaps

Context An expanding body of evidence links dietary factors to major ocular diseases, yet significant regional disparities, particularly the lack of data from sub-Saharan Africa (SSA) limit context-specific understanding and interventions. Objective This systematic review aimed to investigate dietary factors associated with major eye disorders—cataracts, refractive error, glaucoma, diabetic retinopathy, age-related macular degeneration, and dry eye disease—in the SSA population. Data Sources Electronic searches were conducted in PubMed, Scopus, Web of Science, Embase, HINARI, CINAHL, African Journals Online, and CENTRAL without date restrictions to identify interventional (randomized and non-randomized trials), observational (cohort, case-control, cross-sectional), qualitative studies, case reports, and case series examining associations between dietary factors and eye diseases. Data Extraction No independent data extraction was performed, as no eligible studies were identified. Data Analysis Evidence synthesis following Synthesis Without Meta-analysis (SWiM) guidelines was not conducted due to the absence of included studies. The search yielded 391 publications. After title and abstract screening, 14 full-text articles were reviewed for eligibility. However, none met the predefined inclusion criteria. Common reasons for exclusion included irrelevant interventions (eg, surgical or unrelated pharmacological), absence of dietary focus, lack of comparator groups, or outcomes not related to the targeted eye conditions. Conclusions This review highlights a critical evidence gap regarding the role of diet in eye health within SSA. Given the high burden of visual impairment and limited access to conventional treatments in the region necessitates urgent research into affordable diet-based interventions.