The prevalence of refractive errors among schoolchildren in Dezful, Iran

• Published in: British journal of ophthalmology 2007-03, Vol.91 (3), p.287-292
• Main Authors: Fotouhi, Akbar, Hashemi, Hassan, Khabazkhoob, Mehdi, Mohammad, Kazem
• Format: Article
• Language: English
• Subjects: Adolescent; Age; Astigmatism; Astigmatism - epidemiology; Astigmatism - physiopathology; Astigmatism - therapy; BCVA; best corrected visual acuity; Biological and medical sciences; Blindness; Child; Confidence intervals; Epidemiologic Methods; Eyeglasses - utilization; Female; Gender; Humans; Hyperopia - epidemiology; Hyperopia - physiopathology; Hyperopia - therapy; Iran - epidemiology; Male; Medical sciences; Miscellaneous; Myopia; Myopia - epidemiology; Myopia - physiopathology; Myopia - therapy; Needs Assessment; Ophthalmology; Population; Refractive Error Study in Children; Refractive Errors - epidemiology; Refractive Errors - physiopathology; Refractive Errors - therapy; RESC; Rural areas; Sample size; Socioeconomic factors; Students; Studies; UCVA; uncorrected visual acuity; Vision disorders; Visual Acuity; World View
• ISSN: 0007-1161; 1468-2079
• DOI: 10.1136/bjo.2006.099937

Aim: To determine the prevalence of refractive errors among schoolchildren in urban and rural areas of Dezful County, Iran. Methods: In a cross-sectional study, using random cluster sampling, 5721 Dezful schoolchildren were selected from 39 clusters. The participants in the study totalled 5544; 3673 elementary and middle school students and 1871 high school students. For the former group, cycloplegic refraction and for the latter, non-cycloplegic refraction was tested. In all participants, uncorrected visual acuity and best corrected visual acuity were determined, and those with a visual acuity of 20/40 or worse, underwent a complete ophthalmic examination to determine the cause of visual impairment. A spherical equivalent of −0.5 diopter (D) or worse was defined as myopia, +2.0 D or more was defined as hyperopia, and a cylinder refraction greater than 0.75 D was considered astigmatism. Results: The uncorrected visual acuity was 20/40 or worse in the better eye of 224 schoolchildren (3.8% of participants). This figure (percentage) was 14 (0.03%) based on their best corrected visual acuity and 96 (1.7%) with their presenting vision. According to results of cycloplegic refraction, 3.4% (95% confidence interval (CI), 2.5 to 4.4) of the primary and middle school students were myopic and 16.6% (95% CI, 13.6 to 19.7) were hyperopic. For high school students, these rates were 2.1% (95% CI, 0.7 to 3.5) and 33.0% (95% CI, 24.9 to 41.1), respectively, with non-cycloplegic refraction. In the multivariate logistic regression for primary and middle school students, myopia was correlated with age (p = 0.030), and hyperopia was correlated with age (p