Association between Dyslipidemia and Meibomian Gland Dysfunction: A Systematic Review and Meta-Analysis.

PURPOSE: This study aimed to use meta-analysis to estimate the association between dyslipidemia and meibomian gland dysfunction. METHODS: The following databases were searched: PubMed, Google Scholar, and Scopus. Case-control and cohort studies assessing the association between dyslipidemia and meibomian gland dysfunction were included. The association was assessed using odds ratios. Heterogeneity between studies was assessed with the χ2 statistic and degree of inconsistency. The quality of studies was assessed using the Newcastle-Ottawa Scale. The systematic review was registered on PROSPERO (ID: CRD42022347982). RESULTS: The systematic review included three case-control and two cohort studies. The odds of hypercholesterolemia and hypertriglyceridemia in meibomian gland dysfunction were 5.45 (95% confidence interval [CI], 1.65 to 17.95) and 3.28 (95% CI, 1.25 to 8.62), respectively. The odds of elevated serum low-density lipoprotein and reduced high-density lipoprotein in meibomian gland dysfunction were 2.72 (95% CI, 1.24 to 5.98) and 1.15 (95% CI, 0.74 to 1.79), respectively. The current study's limitation is that the effects of sex, age, and meibomian gland dysfunction severity on the association between dyslipidemia and meibomian gland dysfunction were not assessed. CONCLUSIONS: The current study suggests a significant association between dyslipidemia and meibomian gland dysfunction. This finding suggests that meibomian gland dysfunction diagnosis may call for dyslipidemia screening.

Strabismus and amblyopia in Africa - a systematic review and meta-analysis.

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.

PREVALENCE OF MEIBOMIAN GLAND DYSFUNCTION IN AFRICA: A SYSTEMATIC REVIEW AND META-ANALYSIS OF OBSERVATIONAL STUDIES.

PURPOSE: To review and summarize information on meibomian gland dysfunction (MGD) epidemiology in Africa. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Comparison of the performance of the dry eye questionnaire (DEQ-5) to the ocular surface disease index in a non-clinical population.

OBJECTIVE: To compare the performance of the dry eye questionnaire (DEQ-5) with the Ocular Surface Disease Index (OSDI) and further validate the DEQ-5 questionnaire. METHODS: A population-based cross-sectional study conducted in Ghana. OSDI and DEQ-5 questionnaires were administered to participants. Cronbach's alpha was used to evaluate the reliability of the OSDI and DEQ-5 questionnaires. Analysis of variance was used to evaluate the discriminant validity of DEQ-5. Concurrent validity was evaluated using the Spearman correlation analysis. A receiver operating characteristic (ROC) curve was generated to describe the sensitivity and specificity of the DEQ-5 questionnaire for diagnosis of dry eye symptoms. Cohen Kappa was used to evaluate agreement between the two questionnaires. RESULTS: The reliability of the overall OSDI and DEQ-5 scores were 0.919 and 0.819 respectively. The mean (SD) DEQ-5 scores for asymptomatic, mild, moderate and severe dry eye symptoms as defined by the OSDI grading were 3.05 (2.73), 5.13 (3.69), 7.65 (3.30) and 9.77 (4.16) respectively. There was a statistically significant correlation between total OSDI and total DEQ-5 scores (rs = 0.649, p < 0.0001). The area under the curve (AUC) of the ROC curve for DEQ-5 was 0.835 (95 % CI: 0.796 - 0.875). A DEQ-5 threshold of 5.5 yielded maximum sensitivity (0.712) and specificity (0.827). The Cohen kappa using a the DEQ-5 total score threshold of 5.5 was K = 0.539 (p < 0.0001). CONCLUSION: In conclusion, performance of the DEQ-5 questionnaire in discriminating symptoms of dry eye is comparable to the OSDI questionnaire. The DEQ-5 questionnaire is a valid measure of dry eye symptoms and can be used as a dry eye symptoms assessment tool in both clinical and epidemiological studies.

Keratoconus in Africa: A systematic review and meta-analysis.

PURPOSE: The aim of this review is to evaluate the prevalence of and factors associated with keratoconus in Africa. METHOD: A systematic online literature search was conducted for articles on keratoconus in Africa. Meta-analysis was performed to estimate the prevalence of keratoconus in Africa. The Freeman-Tukey double arcsine transformation was used to minimize the effects of studies with extremely high or low prevalence estimates on the overall pooled estimates. Leave-one-out sensitivity analysis was used to assess the robustness of the pooled effects and potential outliers. Meta-regression was performed to explore associations between keratoconus, gender and age. RESULTS: Twelve studies were included in the review; 5 from Egypt, 2 from South Africa, 2 from Kenya, 1 from Sudan, 1 from Ghana and 1 from Nigeria. Two studies were conducted in allergic conjunctivitis patients, 4 in keratoconus patients, 1 in contact lens service seekers, 1 in pre-LASIK patients, 1 in refractive patients and 1 in a student population. Eight studies were included in the meta-analysis. The overall prevalence estimate of keratoconus in Africa was 7.9% (95% CI: 2.5%-16.0%). The prevalence of keratoconus among males and females in Africa was estimated to be 9.3% (95% CI: 2.5%-19.5%) and 5.8% (95% CI: 1.5%-12.7%) respectively. The estimated prevalence of unilateral and bilateral keratoconus was 2.6% (95% CI: 0.4%-6.5%) and 5.8% (95% CI: 1.6%-12.3%), respectively. The estimated prevalence of mild keratoconus was 2.2% (95% CI: 0.7%-4.7%), moderate keratoconus was 3.5% (95% CI: 0.0%-11.8%) and severe keratoconus was 4.0% (95% CI: 0.0%-19.6%). There was no significant association between gender and the prevalence of keratoconus in Africa (p = 0.63), and age and the prevalence of keratoconus in Africa (p = 0.78). CONCLUSION: The estimated prevalence of keratoconus reported here is higher than prevalence values reported in other meta-analyses or different geographical locations. This is mainly because studies included in this meta-analysis were either conducted on a cohort at high risk of keratoconus or a population with high possibility of finding keratoconus patients. There is a dearth of well-designed population-based studies on keratoconus in Africa, resulting in a lack of epidemiological information. This highlights the urgent need for research on keratoconus in Africa.