Update on Epidemiologic Trends in Causes of Childhood Blindness and Severe Visual Impairment in East Africa

Abstract

Objective: The initiative 2030 In Sight and the International Agency for the Prevention of Blindness have developed a plan to mitigate the global burden of preventable sight loss. One priority of this initiative is obtaining population eye health data. East Africa is a region that has historically been plagued by high rates of vision loss, and it is imperative to understand what causes are at play. Two large cross-sectional studies were previously published in 1995 and 2009, reporting the causes of childhood blindness (BL) and severe visual impairment (SVI) in East Africa. An update regarding more recent causes is warranted to better understand the trends of childhood BL/SVI in this region.

Methods: A search strategy was developed a priori to identify relevant terms and align them with a standardized definition of East Africa. This strategy was then employed across PubMed, Google Scholar, and Scopus, with the yield of the overall search depicted in a Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 flow diagram. In the articles gathered by the search, causes of BL/SVI were typically categorized by anatomy and etiology.

Results: Eight articles met the criteria, with data from 6 countries, consisting of 534 cases of childhood BL/SVI. Common anatomic locations identified included the cornea, lens, and whole globe. Among the most common etiologies were corneal scarring/opacity and cataract. Systemic etiologies and disease associations included measles, toxoplasmosis, and prematurity. Presumptive infectious disease and hereditary conditions were also identified as a category, but specific identification of etiologies and genetic diagnosis was largely unavailable.

Conclusions: BL/SVI due to the cornea was among the common anatomic sites of disease in our study. The identification of measles as an associated systemic etiology requires further understanding in the context of increased vaccination programs. Multiple articles acknowledged that cataract has become the predominant cause of BL/SVI owing to increased measles vaccination and vitamin A supplementation. Additional research should be conducted to gain a complete understanding of childhood BL/SVI in East Africa, and responses at regional and national levels are likely necessary to address treatable causes of vision impairment.