The prevalence of amblyopia in ۷–۹-year-old schoolchildren in Mashhad

Abstract Background: To determine the prevalence of amblyopia in schoolchildren aged ۷–۹ years old in Mashhad, Iran. Methods: This was a cross-sectional, community-based study with schoolchildren aged ۷–۹ years old. We randomly selected ۲۰ of ۱۸۹ elementary schools (three schools per district; ۱۰ male-segregated and ۱۰ female-segregated schools) from a proportional combination of public schools across Mashhad. Basic vision exams were performed. If amblyopia was suspected, children underwent supplementary vision exams. The diagnostic criterion for amblyopia was a best corrected visual acuity (BCVA) in one or both eyes equal to or worse than ۲۰/۴۰ or an interocular difference of more than two lines in BCVA without any significant organic pathology. Results: A total of ۲۸۳۱ children were included in the study. All children were examined comprehensively by an optometrist, and amblyopia was detected in ۴۹/۲۸۳۱ (۱.۷% [۹۵% CI, ۱.۲۲?۲.۱۸]). Of the ۴۹ children with amblyopia, ۲۰ (۴۰.۸%) were amblyopic in the right eye, ۹ (۱۸.۴%) in the left eye, and ۲۰ (۴۰.۸%) in both eyes. Twenty-four (۴۹%) were first graders, ۱۵ (۳۰.۶%) were second graders, and ۱۰ (۲۰.۴%) were third graders. The most prevalent subtype of amblyopia was anisometropic amblyopia (۵۷.۱%, [۹۵% CI, ۴۳.۲۴?۷۰.۹۶]). Conclusions: Considering the prevalence of amblyopia among schoolchildren aged ۷–۹ years old (۱.۷%), timely detection of amblyopia through preschool screening programs is essential for early treatment or prevention of further visual impairment during childhood. Keywords: amblyopia prevalence elementary school preschool children Iran Mashhad diagnostic screening program