Epidemiological data about the prevalence of amblyopia around the world vary widely among regions and periods. This meta-analysis aimed to determine the global prevalence of amblyopia in children. PubMed, Embase, and the Cochrane Library were searched for prevalence studies published up to 5 November 2021. The outcome was the prevalence of amblyopia, analyzed as pooled estimates with 95% confidence intervals (CI). A total of 97 studies were included, including 4,645,274 children and 7,706 patients with amblyopia. The overall worldwide pooled prevalence of amblyopia was 1.36% (95%CI: 1.27–1.46%). The prevalence of amblyopia was higher in males (1.40%, 95%CI: 1.10–1.70%) than in females (1.24%, 95%CI: 0.94–1.54%) (OR = 0.885, 95%CI: 0.795–0.985, P = 0.025). The results of the meta-regression analysis showed that there were no significant associations between the prevalence of amblyopia and geographical area, publication year, age, sample size, and whether it was carried out in a developed or developing country (all P > 0.05). Begg’s test (P = 0.065) and Egger’s test (P < 0.001) showed that there was a significant publication bias in the prevalence of amblyopia. In conclusion, amblyopia is a significant vision problem worldwide, and public health strategies of early screening, treatment, and management are important.

The size of male manubrium is significantly larger than that of female manubrium. Manubrium bone is far more sufficient for most adult anterior cervical fusion surgeries. Safe area for procurement of graft is defined as the upper two-thirds of manubrium, and the optimal site to access medullar cavity is suggested at bare area. However, because considerable variability of manubrium size exists, preoperative evaluation of manubrium is suggested to avoid pitfalls, especially when manubrium graft is intended in a female patient.