The prevalence of anisometropia, amblyopia and strabimus in schoolchildren of Bojnourd, Iran

Abstract

Abstract Purpose To determine the prevalence of anisometropia, amblyopia and starbimus in schoolchildren of Bojnourd, Iran. Methods A random cluster sampling was used in a cross‐sectional study on 2020 schoolchildren in Bojnourd, northeast of Iran. The participants totaled 1551;643 boys and 908 girls. Mean age of the partipiciants was 11.12 years (respose rate=76.7%). Examinations included: uncorrected and best corrected visual acuity (UCVA and BCVA) measurements, cycloplegic refraction and cover test. Anisometropia defined as spherical equivalent (SE) refraction difference 1.00 D and more between two eyes. Amblyopia was defined as a reduction of BCVA to 20/30 or less in one eye or two lines introcular optotype acuity difference in the absence of pathological causes. Strabismus was characterized as a heterotropia at distance or near fixation. Results The prevalence of anisometropia, amblyopia and strabismus were 2.7%, 2.2 and 2% respectively and were not related to the gender. The prevalence of exotropia, esotropia and hypertropia were 1.37%, 0.51% and 0.12% respectively. Conclusion Prevalence of anisometropia, amblyopia and strabismus among the schoolchildren of Bojnourd were in the mid range and similar to that in most places of the world. Exotropia was the most common strabismus type and comparable to the other Asian countries.