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A systematic review of Amblyopia prevalence among the children of the world
Ali Mostafaie1, Morteza Ghojazadeh2, Hossein Hosseinifard2
1Department of Ophthalmology, Nikookari Ophthalmology University Hospital, Tabriz University of Medical Sciences, Tabriz, Iran.
Insights
This systematic review found the global prevalence of Amblyopia, or lazy eye, in children to be 4.3%. Prevalence varied by continent, with America showing the highest rates and Africa the lowest, likely due to study heterogeneity.
Area of Science:
- Ophthalmology
- Public Health
- Epidemiology
Background:
- Amblyopia, commonly known as lazy eye, is a significant cause of visual impairment in children worldwide.
- Accurate prevalence data is crucial for understanding the global burden of Amblyopia and informing public health strategies.
- Previous estimates of Amblyopia prevalence have varied, necessitating a comprehensive global assessment.
Purpose of the Study:
- To systematically review and meta-analyze the global prevalence of Amblyopia in children.
- To identify variations in Amblyopia prevalence across different continents.
- To explore potential reasons for heterogeneity in prevalence estimates.
Main Methods:
- A systematic review and meta-analysis was conducted using the PICO framework.
- Extensive literature searches were performed across major databases including Medline (PubMed), Embase, Scopus, Web of Science, and ProQuest.
- Data extraction and critical appraisal were performed by two independent reviewers, with prevalence pooled using Comprehensive Meta-analysis Software (CMA v.2).
Main Results:
- A total of 131 studies, encompassing 952 retrieved citations, were included in the analysis.
- The pooled global prevalence of Amblyopia in children was calculated at 4.3% (95% CI: 2.6%-7.00%).
- Significant heterogeneity was observed (I-squared: 99.88%), with the Americas reporting the highest prevalence (5.57%) and Africa the lowest (7.1%).
Conclusions:
- The global prevalence of Amblyopia in children is estimated at 4.3%, with considerable variation across continents.
- High heterogeneity among studies, potentially due to differences in populations, disease severity, age, and gender, significantly impacts prevalence estimates.
- Further high-quality, standardized global studies are essential to accurately determine the true prevalence of Amblyopia in children worldwide.
Abstract:
Objective: to assess the prevalence of Amblyopia disease in the children of the world. Methods: In order to perform this systematic review, PICO was considered as the research question. Then, the preferred keywords were searched in Medline (via PubMed), Embase, Scopus, Web of Science, and ProQuest databases. The retrieved citations were reviewed by two independent inspectors in a three-step process in terms of the title, abstract, and full-text, based on the inclusion criteria. The studies included in the review were critically evaluated and then were extracted by two dependent expert reviewers. Finally, the prevalence of Amblyopia disease in the children of the world was pooled by meta-analysis CMA v.2 software. The heterogeneity of the selected studies was evaluated using I2 and chi-square. Also, subgroup-analysis was performed using designs and continents. Results: Out of 952 retrieved citations, 131 studies were included. The total prevalence of Amblyopia in the children of the world was calculated to be 4.3% [Pooled Prevalence: 4.3%, 95% CI: 2.6%-7.00%, P-value 0.0001]. In addition, the heterogeneity of the studies was reported to be high (Q: 48281.18, df: 56, p-value 0.001, I-square: 99.88). The subgroup analysis showed that America had the highest (5.57%, 95% CI: 2.23%-13.94%, P-value 0.0001) prevalence, and the lowest prevalence of Amblyopia in the children of the world was seen in Africa (7.1%, 95% CI: 0.003%-172.53%, P-value 0.05). Conclusion: It can be concluded that the total prevalence of Amblyopia is 3.4%, but this estimate varies in all continents, especially in Africa. The major reason for this variation was reported to be the heterogeneity of studies. These assessments have investigated different populations in terms of severity of illness, age, and gender. Therefore, further worldwide high-quality and valid studies should be carried out to allow the calculation of the real prevalence of Amblyopia among children of the world. Abbreviations: VA = visual acuity, ALSPAC = Avon Longitudinal Study of Parents and Children, JBI = Joanna Briggs Institute, PRISMA = Systematic Review and Meta-analysis, CMA = Comprehensive Meta-analysis Software.
