Prevalence of blindness and its major causes in sub-Saharan Africa in 2020: A systematic review and meta-analysis

Background:
Global studies show that the prevalence of visual impairment and blindness
continued to rise despite the implementation of strategies outlined in the Global Action Plan, aimed
at reducing these by the year 2020. Vision impairment impacts negatively on one’s independence,
opportunities, and quality of life. Therefore, knowledge of the prevalence, and the major causes of
blindness impairment in any population, is vital in designing strategies to address this public health
challenge.

Methods:
Literature mapping evidence of vision impairment was searched for on PubMed,
Google Scholar, and EBSCOhost databases MEDLINE, Health Source: Nursing/Academic Edition,
Health Source – Consumer Edition, CINAHL, and Academic Search Complete. Studies that
were searched for included peer-reviewed and grey literature published in English from various
countries in sub-Saharan Africa (SSA).

Results:
Only 77 studies with 191,173 participants, contributing data from 26 countries within
SSA, met the inclusion criteria for the final review. The overall pooled prevalence estimate (PPE)
of blindness from the selected studies was 10% (95% confidence interval [CI]: 8.0% – 11.0%).
West Africa and East Africa had the highest prevalence. The identified leading causes of blindness
were cataracts (46%; 95% CI: 40% – 52%), followed by glaucoma (14%; 95% CI: 11% – 18%).
There was a high level of heterogeneity in most pooled estimates (I2 ˃ 80%, p<.001).

Conclusion:
The prevalence of blindness in SSA has increased in all four regions with most
cases being avoidable. Policymakers should prioritise blindness prevention programmes, ensure
enabling health systems, and provide the necessary resources towards reducing blindness in SSA.