Normative corneal biometric parameters in African populations: A systematic review and meta-analysis

Background: Despite the importance of corneal biometric parameters in ophthalmology, there is limited comprehensive data on these measurements in Sub-Saharan African (SSA) populations. This study systematically reviewed the evidence on corneal biometric parameters of Sub-Saharan African populations, focusing on their variability, influencing factors, and implications for clinical practice and public health interventions. Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. Eligible studies published between January 2003 and December 2023 were identified through comprehensive searches in PubMed, Scopus, and Web of Science, with a specific focus on African populations. Inclusion criteria comprised non-interventional studies reporting central corneal thickness (CCT), corneal curvature, radius of curvature, or horizontal corneal diameter (HCD) of eyes of continental Africans. Data were synthesized using random-effects meta-analyses, with heterogeneity assessed using the I² statistic. Subgroup analyses examined variations by geographic region, measurement instrument, and sex. Results: Twenty-eight studies with a total of 14,009 participants were included. The pooled mean CCT was 553.35 µm (95 % CI: 548.52–558.18 µm), with regional variations ranging from 555.66 µm in West Africa to 510.17 µm in Southern Africa. Males exhibited slightly higher CCT values compared to females (539.11 µm vs. 533.78 µm). Additional parameters assessed included mean corneal curvature (43.07 D), radius of curvature (7.70 mm), and HCD (11.59 mm). Variability in the measurements was attributed to demographic, geographic, and methodological factors. Conclusions: Corneal biometric parameters exhibit substantial regional and demographic variability in SSA. These findings underscore the importance of population-specific data in enhancing diagnostic precision and guiding the development of regionally tailored clinical protocols. Further research is needed to address current knowledge gaps and improve eye care outcomes across the African continent. Funding: This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.