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The objective of this review was to estimate the prevalence of strabismus and amblyopia in Africa. A systematic online literature search was conducted for articles on strabismus and amblyopia in Africa. Meta-analysis was performed, using the Freeman-Tukey double arcsine transformation, to estimate the prevalence of strabismus and amblyopia in Africa. Subgroup analyses were conducted according to age, gender, study year, and type of amblyopia. Meta-regression was used to evaluate the influence of predetermined factors on the prevalence of amblyopia. 8 (1 population-based & 7 school-based) and 21 (3 population-based & 18 school-based) studies on strabismus and amblyopia with sample sizes of 22,355 and 46,841, respectively, were included in the review. Overall prevalence of strabismus in Africa was estimated to be 0.8% (95% CI: 0.4% − 1.4%); exotropia was 0.2% (95% CI: 0.1% − 0.5%) and esotropia was 0.5% (95% CI: 0.1% − 1.2%). Overall prevalence of amblyopia was estimated to be 0.6% (95% CI: 0.3% − 0.9%); refractive and strabismic amblyopia were 1.1% (95% CI: 0.2% − 2.5%) and 0.4% (95% CI: 0.2% − 0.6%), respectively. Prevalence estimate of amblyopia in males was 1.8% (95% CI: 0.7% − 3.3%) and in females was 1.3% (95% CI: 0.4% − 2.6%). There was a significant association between the prevalence of amblyopia and the type of amblyopia (p =.007) and the study year (p =.006). Although there appears to be a relatively low prevalence of strabismus and amblyopia in Africa, there is a dearth of well-designed population-based studies on strabismus and amblyopia in Africa, resulting in the lack of epidemiological information on strabismus and amblyopia within the general African population. Information about the prevalence of strabismus and amblyopia across Africa can inform policy making and design and implementation of public health intervention program. [ABSTRACT FROM AUTHOR]

To review and summarize information on meibomian gland dysfunction (MGD) epidemiology in Africa. A systematic search of online databases was conducted for literature/studies on MGD in Africa. Meta-analysis was conducted to estimate the prevalence of MGD in Africa. Meta-regression was used to explore sources of heterogeneity. Twelve studies conducted in five countries were included in the review. All studies were hospital-based studies. Nine studies were included in the meta-analysis; the total sample size was 4963 and participants' age range was 17–96 years. The overall prevalence estimate of MGD in Africa was 45.9% (95% CI: 27.6–64.1%). Prevalence of MGD among males and females were each pooled from three studies and in urban and rural setting from 6 and 3 studies, respectively. Prevalence of MGD among males and females were 56.0% (95% CI: 22.4–89.5%) and 58.9% (95% CI: 28.5–89.4%) respectively; in urban and rural settings were 42.8% (95% CI: 21.1–64.5%) and 65.7% (95% CI: 25.7–95.7%), respectively. There was no association of MGD with sex (p =.872) and with study setting (p =.231). There is a paucity of evidence on MGD prevalence in Africa, emphasizing the need for epidemiological studies to enhance our understanding of region-specific differences in MGD in Africa. The pooled estimate from hospital-based studies, however, suggests a substantial MGD burden in Africa. Epidemiological studies are needed to assess if this translates to a high disease burden within the general African population. [ABSTRACT FROM AUTHOR]

This paper examines the relationship and related causality patterns of oil price volatility and exchange rate volatility of a group of oil-dependent economies before and after the 2008–2009 global financial crisis. We employed weekly time-series data of oil price and exchange rates for 2000–2007 (pre-crisis) and 2010–2016 (post-crisis). United States dollar exchange rates are for Ghanaian cedi, Nigerian naira, Russian ruble, Indian rupee, South African rand, and the Euro. To investigate the volatility impacts that exist between oil price and exchange rates during both sub-sample periods, we merged Vector Autoregressive (VAR) with GARCH and EGARCH models in the form of Bivariate VAR-GARCH and VAR-EGARCH. We further adopted the Toda-Yamamoto causality test to investigate related causality patterns. Empirical findings revealed both bidirectional and unidirectional relationship between oil price volatility and the exchange rates volatility of four out of the six oil-dependent economies considered for the study. These findings were more prevalent in the post-crisis period than the pre-crisis period. We also confirmed both bidirectional and unidirectional causality pattern between oil price volatility and exchange rate volatility of the same four currencies as observed with the VAR results in both sub-sample periods. [ABSTRACT FROM AUTHOR]