Author/Authors :
Yekta, AbbasAli Vision Sciences Research Center - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Ostadimoghaddam, Hadi Vision Sciences Research Center - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Azimi, Abbas Vision Sciences Research Center - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Khadem Maboudi, Ali Akbar Department of Biostatistics - Faculty of Paramedical - Shahid Beheshti University of Medical Sciences, Tehran , Hashemi, Hassan Noor Ophthalmology Research Center - Noor Eye Hospital, Tehran , Rezvan, Farhad Noor Ophthalmology Research Center - Noor Eye Hospital, Tehran , Khabazkhoob, Mehdi Noor Ophthalmology Research Center - Noor Eye Hospital, Tehran , Azizi, Elham Department of Optometry - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Derakhshan, Akbar Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran
Abstract :
Purpose: To determine the prevalence of amblyopia and strabismus in the schoolchildren of the city
of Bojnourd, Iran
Methods: In 2010, randomized stratified cluster sampling was employed in a cross-sectional study
on primary and junior high schoolchildren. All the examinations were performed in schools. All
students received refraction, vision and subjective refraction tests. The cover test was used to
determine tropia. Amblyopia was defined as best corrected visual acuity (BCVA) 20/30 or less or a
2-line interocular optotype acuity difference with no pathology.
Results: Of 2,020 selected students, 1,551 participated in the study (response rate: 76.7%). The
prevalence of amblyopia was 2.3% (95% CI: 1.6-3.1); 2% of the male students and 2.5% of the
female students had amblyopia (P=0.508). Amblyopia decreased significantly with age (P=0.032).
The most common type of amblyopia was anisometropic followed by isometropic amblyopia.
Hyperopia and astigmatism were the most common refractive errors in individuals with amblyopia.
The prevalence of strabismus in the students was 2% (95% CI: 1.3-2.7). Of female and male
students, 2.4% and 1.4% had strabismus, respectively (P=0.160). Of the students with strabismus,
67.7%, 25.8% and 6% had exotropia, esotropia and vertical deviations, respectively.
Conclusion: The prevalence of amblyopia and strabismus in the current study was intermediate.
However, correction of refractive errors at young ages can largely prevent amblyopia and
strabismus in children.
