The Prevalence of Refractive Errors, Strabismus and Amblyopia in Schoolboys of Varamin, Iran, in 2010

Purpose: To determine the prevalence of refractive errors, strabismus and amblyopia in the schoolboys of Varamin city, Iran Methods: In a cross-sectional population-based study in 2010, we used random cluster sampling to select the participants from Varamin high school students. Examinations were conducted at the school site under standard conditions. All students had non-cycloplegic refraction, visual acuity (VA) test and cover test. Results: Of the 1,430 selected, 79.2% participated in the study: their mean age was 16.3±1.3 years (range, 14 to 18). The prevalence of myopia [spherical equivalent (SE)≤-0.5 diopter (D) ], hyperopia (SE≥+0.5 D) and hyperopia (SE≥+1.0 D) were 33.2% (95% confidence interval (CI) : 25.0 to 41.4), 17.5% (95% CI: 8.6 to 26.4) and 6.1% (95% CI: 2.6 to 9.6), respectively. Astigmatism (cyclinder power ≥0.75 D) and anisometropia (difference in SE ≥1.0 D) were detected in 10.5% (95% CI: 8.4 to 12.6) and 3.8% (95% CI: 1.8 to 5.8) of the students. The prevalence of strabismus was 1.5% (95% CI: 0.9 to 2.1) and exotropia was the most prevalent type of strabismus (0.9%). The prevalence of amblyopia was 2.1% and anisometropia was the most common cause (54.2%). There was an unmet need for refractive correction in 15.4% (95% CI: 13.3 to 17.4) of the students. Conclusion: The most common refractive error in the students in this study was myopia, however, the prevalence rate of hyperopia was relatively higher than that in other studies. The unmet need for refractive correction was higher as well. In comparison to other populations, the prevalence of strabismus was low while the prevalence of amblyopia was similar.