Elsevier

Ophthalmology

Volume 114, Issue 2, February 2007, Pages 374-382.e1
Ophthalmology

Original Article
Refractive Error and Visual Impairment in School Children in Rural Southern China

https://doi.org/10.1016/j.ophtha.2006.08.020Get rights and content

Purpose

To assess the prevalence of refractive error and visual impairment in school children in a rural area of southern China.

Design

Prospective cross-sectional survey.

Participants

Two thousand four hundred children from junior high schools in Yangxi County.

Methods

Random selection of classes from the 3 junior high school grade levels was used to identify the study sample. Children from 36 classes in 13 schools were examined in April 2005. The examination included visual acuity (VA) testing; ocular motility evaluation; cycloplegic autorefraction; and examination of the external eye, anterior segment, media, and fundus.

Main Outcome Measures

Distance VA and cycloplegic refraction.

Results

Among 2515 enumerated children, 2454 (97.6%) were examined. The study population consisted of the 2400 children between 13 and 17 years old. Prevalences of uncorrected, presenting, and best-corrected VA ≤ 20/40 in the better eye were 27.0%, 16.6%, and 0.46%, respectively. Sixty percent of those who could achieve acuity ≥20/32 in at least one eye with best correction were without the necessary spectacles. Refractive error was the cause in 97.1% of eyes with reduced vision; amblyopia, 0.81%; other causes, 0.67%; and unexplained causes, 1.4%. Myopia (spherical equivalent, −0.50 diopters [D] or more in either eye) affected 36.8% of 13-year-olds, increasing to 53.9% of 17-year-olds. Myopia was associated with higher grade level, female gender, schooling in the county urban center, and higher parental education. Hyperopia (+2.00 D or more) affected approximately 1.0% in all age groups. Astigmatism (≥0.75 D) was present in 25.3% of all children.

Conclusions

Reduced vision because of uncorrected myopia is a public health problem among school-age children in rural China. Effective VA screening strategies are needed to eliminate this easily treated cause of visual impairment.

Section snippets

Sample Selection

Stratified cluster sampling was used to select the study sample. The sampling frame was constructed through enumeration of grade-specific classes within the 17 county schools. Each class, with anywhere between 50 and 80 students, represented a sampling frame cluster. Based on Bureau of Education data, 8382 students were enrolled in 132 classes at the seventh grade level, 7400 were in 112 classes at the eighth grade level, and 5628 were in 88 classes at the ninth grade level. Stratification of

Study Population

The enumeration and examination of children took place during April 2005. A total of 2454 children were examined, representing 97.6% of the 2515 enumerated. Distributions across age, gender, grade level, school location, and residence are shown in Table 1. Because of small numbers, meaningful estimates of myopia rates for 12- and 18-year-olds (54 examined subjects) were not possible, and they were excluded from the study population.

Visual Acuity

Visual acuity findings are presented in Table 2. Uncorrected

Discussion

This study provides estimates of the prevalence of refractive error and visual impairment in junior high school children in rural Yangxi County. Findings indicate that myopia prevalence is higher among children attending schools in the urban center of the county than among those in schools in the rural countryside. These urban–rural comparisons were not possible in the previous Shunyi District survey because it excluded the urban center of the district, expecting that obtaining access for

References (29)

  • K.S. Naidoo et al.

    Refractive error and visual impairment in African children in South Africa

    Invest Ophthalmol Vis Sci

    (2003)
  • Bureau of Statistics of GuangDong Province. 2004 income and expenditure of rural residents in Guangdong [in Chinese]....
  • S.M. Saw et al.

    Nearwork in early-onset myopia

    Invest Ophthalmol Vis Sci

    (2002)
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    Manuscript no. 2005-1027.

    Supported by the World Health Organization, Geneva, Switzerland, under National Institutes of Health contract no. N01-EY-2103.

    The authors have no financial or other conflicts of interest concerning the study.

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