Prevalence of color vision deficiency in Africa: Systematic review and meta-analysis

Color vision deficiency (CVD) cause is the difficulty distinguishing colors, which can present vocational and avocational challenges. There is a lack of data on its overall prevalence of CVD. Therefore, this systematic review and meta-analysis aim to determine the prevalence of CVD in Africa.

The protocol was registered with the Prospective Register of Systematic Reviews (PROSPERO) database (protocol registration number: CRD42024510403). A comprehensive systematic literature search was conducted via PubMed/MEDLINE/EMBASE, Google, and Google Scholar from February 2024 to May 28, 2024. The Johanna Bridges Institute quality appraisal tool was used to assess the quality of eligible articles. The pooled prevalence of CVD among Africans was estimated using a random effect model and expressed as prevalence and odds ratios with 95% confidence intervals using Der Simonian-Laird weight. The I2 statistic test was used to measure heterogeneity, and subgroup analysis was performed based on country, source of population, and gender.

A total of 502 initial studies were identified, and sixteen cross-sectional studies were included. The overall pooled prevalence of CVD in Africa was 2.71% (95% CI: 2.28,3.14, I2 = 72.6%, P<0.001). The prevalence among African males and females was 2.13% and 0.34%, respectively. The highest pooled prevalence was recorded in Ethiopia at 3.63% and the prevalence among primary and secondary school students was 2.96%. A funnel plot showed that all of the studies were symmetric, and the Egger test showed no publication bias.

The pooled prevalence of color vision deficiency in Africa was found to be 2.71%. The highest prevalence was reported in studies conducted among school-age children in Ethiopia. Establishing effective screening programs and raising public awareness are recommended as future steps.