Exploring the Link: A Systematic Review and Meta-Analysis on the Prevalence and Association Between Refractive Errors and Intermittent Exotropia.

Background And Aims: Refractive errors and intermittent exotropia are prevalent conditions in pediatric populations, impacting visual development and quality of life. Despite the co-occurrence of conditions such as myopia, hypermetropia, and astigmatism with strabismus, comprehensive analyses of their coexistence are limited. This study aims to investigate the prevalence and characteristics of refractive error among children with intermittent exotropia and find the correlation between the angle of deviation for far and near with factors like mean spherical equivalent and age.

Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. PubMed and Scopus databases were searched up to February 13, 2024. Inclusion criteria encompassed studies detailing clinical presentation, management strategies, and outcomes, while exclusion criteria eliminated review articles, conference abstracts, animal research, and studies with inadequate clinical information. Data extraction and quality assessment were independently performed by multiple reviewers, with discrepancies resolved through consensus. Forest plot was used to show the mean spherical equivalent and the angle of deviation, while publication bias was demonstrated using funnel plot with Egger test.

Results: The search yielded 932 articles, with 23 meeting the inclusion criteria. Studies represented four geographical regions, with a combined sample size of 5407 participants aged 3-10 years. The mean refractive errors varied widely, with an overall pooled mean of -1.787 (95% CI: -5.392 to 1.818). Overminus lens therapy and surgical interventions were common management strategies, with surgery prevalent in cases with higher distant angle deviation. The myopia was more prevalent than hypermetropia (26.82%/16.10%). Meta-regression showed that the mean spherical equivalent had a significant effect on the angle of deviation far and near.

Conclusion: There was a significant correlation between myopia and intermittent exotropia in Middle Eastern and Asian pediatric populations. Myopia is notably more prevalent with significant effect of mean spherical equivalent on near-angle deviation.