Author/Authors :
Ostadimoghaddam, Hadi Department of Optometry - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Yekta, AbbasAli Department of Optometry - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Heravian, Javad Department of Optometry - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Azizi, Elham Department of Optometry - School of Paramedical Sciences - Mashhad University of Medical Sciences, Mashhad , Hashemi, Hassan Noor Ophthalmology Research Center - Noor Eye Hospital, Tehran , Amiri, Mosa Noor Ophthalmology Research Center - Noor Eye Hospital, Tehran , Khabazkhoob, Mehdi Noor Ophthalmology Research Center - Noor Eye Hospital, Tehran , Derakhshan, Akbar Khatam-al-Anbia Eye Hospital - Mashhad University of Medical Sciences, Mashhad , Norouzirad, Reza Dezful University of Medical Sciences, Dezful
Abstract :
Purpose: To determine the prevalence of the uncorrected refractive errors in Bojnourd students
Methods: In a cross-sectional study, the samples were selected proportionate to the population of
the schools using stratified randomized cluster sampling. The target population was the primary
and junior high school students of the city of Bojnourd. Visual acuity (VA) (Snellen chart) and
cycloplegic, non-cycloplegic and subjective refraction were measured in all students. Uncorrected
visual acuity (UCVA) was defined as improvement in corrected vision for at least 2 lines as
compared to the presenting vision.
Results: Of 2,020 selected students, 1,551 were included in the study (response rate 76.7%). The
prevalence of uncorrected refractive errors was 6.2% (95% CI: 5-7.4) in at least one eye and 2.8%
of the students had uncorrected refractive errors in both eyes. The prevalence of the uncorrected
refractive errors was marginally higher in girls (p=0.068). Age, education level of the father and
employment of the mother did not correlate with uncorrected refractive error. Myopic individuals
followed by astigmatic students had the highest uncorrected refractive error. The presenting vision
did not differ with the corrected vision in 83.3% of the participants. In 2.5% and 0.8% of the study
population, vision improved by at least 3 and 4 lines after correcting vision, respectively. In
individuals with glasses, the vision improved by at least 2, 3 and 4 lines in 21.1%, 9.5% and 3.2%
respectively as compared to their present glasses.
Conclusion: The prevalence of the uncorrected refractive errors in students was not low in this
study. Girls, myopes, and cases of astigmatism showed high rates of uncorrected refractive errors,
and it is important that they receive attention. Correcting these errors can help prevent visual
impairment at young ages. Identifying uncorrected refractive errors should be among priorities of
the health system, specially for students.
