Ghaderi Soraya, Hashemi Hassan, Jafarzadehpur Ebrahim, Yekta Abbasali, Ostadimoghaddam Hadi, Mirzajani Ali, Khabazkhoob Mehdi
Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran.
Department of Optometry, School of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran.
Clin Exp Optom. 2018 May;101(3):380-385. doi: 10.1111/cxo.12646. Epub 2017 Nov 22.
To report the prevalence and causes of visual impairment in seven-year-old children in Iran and its relationship with socio-economic conditions.
In a cross-sectional population-based study, first-grade students in the primary schools of eight cities in the country were randomly selected from different geographic locations using multistage cluster sampling. The examinations included visual acuity measurement, ocular motility evaluation, and cycloplegic and non-cycloplegic refraction. Using the definitions of the World Health Organization (presenting visual acuity less than or equal to 6/18 in the better eye) to estimate the prevalence of vision impairment, the present study reported presenting visual impairment in seven-year-old children.
Of 4,614 selected students, 4,106 students participated in the study (response rate 89 per cent), of whom 2,127 (51.8 per cent) were male. The prevalence of visual impairment according to a visual acuity of 6/18 was 0.341 per cent (95 per cent confidence interval 0.187-0.571); 1.34 per cent (95 per cent confidence interval 1.011-1.74) of children had visual impairment according to a visual acuity of 6/18 in at least one eye. Sixty-six (1.6 per cent) and 23 (0.24 per cent) children had visual impairment according to a visual acuity of 6/12 in the worse and better eye, respectively. The most common causes of visual impairment were refractive errors (81.8 per cent) and amblyopia (14.5 per cent). Among different types of refractive errors, astigmatism was the main refractive error leading to visual impairment. According to the concentration index, the distribution of visual impairment in children from low-income families was higher.
This study revealed a high prevalence of visual impairment in a representative sample of seven-year-old Iranian children. Astigmatism and amblyopia were the most common causes of visual impairment. The distribution of visual impairment was higher in children from low-income families. Cost-effective strategies are needed to address these easily treatable causes of visual impairment.
报告伊朗7岁儿童视力损害的患病率、病因及其与社会经济状况的关系。
在一项基于人群的横断面研究中，采用多阶段整群抽样从该国8个城市的小学一年级学生中随机选取不同地理位置的学生。检查包括视力测量、眼球运动评估以及散瞳和不散瞳验光。本研究采用世界卫生组织的定义（较好眼的最佳矫正视力小于或等于6/18）来估计视力损害的患病率，并报告了7岁儿童的视力损害情况。
在4614名选定的学生中，4106名学生参与了研究（应答率89%），其中2127名（51.8%）为男性。根据视力6/18计算，视力损害的患病率为0.341%（95%置信区间0.187 - 0.571）；至少一只眼睛视力为6/18的儿童中，视力损害的患病率为1.34%（95%置信区间1.011 - 1.74）。分别有66名（1.6%）和23名（0.24%）儿童较差眼和较好眼的视力为6/12，存在视力损害。视力损害最常见的原因是屈光不正（81.8%）和弱视（14.5%）。在不同类型的屈光不正中，散光为导致视力损害的主要屈光不正类型。根据集中指数，低收入家庭儿童视力损害的分布更高。
本研究揭示了具有代表性的伊朗7岁儿童样本中视力损害的高患病率。散光和弱视是视力损害最常见的原因。低收入家庭儿童视力损害的分布更高。需要采取具有成本效益的策略来解决这些易于治疗的视力损害原因。
