Exceptionally low prevalence of refractive error and visual impairment in schoolchildren from Lao People's Democratic Republic.
OBJECTIVE
Vientiane Province is an urbanizing region in Southeast Asia. We aimed to determine the prevalence of refractive error and visual impairment in primary school-aged children in this region.


METHODS
Prospective, cross-sectional survey.


METHODS
A total of 2899 schoolchildren from Vientiane Province, Lao People's Democratic Republic (Lao PDR).


METHODS
Ten districts from Vientiane were randomly selected and 2 primary schools were randomly selected from each district. All children aged 6 to 11 years at selected schools were eligible to participate. The examination included visual acuity (VA) testing, cycloplegic retinoscopy with subjective refinement if indicated, ocular motility testing, and anterior segment and fundus examinations in visually impaired children.


METHODS
Cycloplegic refraction and VA.


RESULTS
There was an estimated total of 3330 children who were eligible to participate, and data were recorded from 2899 (87%) of these children. Complete refractive data were available on 2842 children (85% of eligible population). The mean spherical equivalent (SE) in the right eyes was +0.60 diopter (D) (95% confidence interval [CI], 0.49-0.72), and the mean SE in the left eyes was +0.59 (95% CI, 0.50-0.68). The prevalence of hyperopia was 2.8% (95% CI, 1.9-3.7; 88 subjects), and the prevalence of myopia was 0.8% (95% CI, 0.3-1.4; 24 subjects). The majority of children (98%; 95% CI, 97.0-99.0) had normal unaided binocular VA (at least 20/32 in their better eye). The overall prevalence of any visual impairment (presenting VA <20/32 in the better eye) was 1.9% (95% CI, 1.0-2.9; 55 subjects). In multivariate logistic regression analysis, age (P = 0.001) was a significant predictor, and female gender (P = 0.08) and Yao ethnicity (P = 0.09) were borderline significant predictors of the presence of any visual impairment.


CONCLUSIONS
Visual impairment is not a public health concern in this primary school-aged population; however, visually impaired children in the community were not studied. From this baseline, future surveys could determine the effect of increasing urbanization on myopia prevalence in this population.
South Australian Institute of Ophthalmology, University of Adelaide University and Sight for All, Adelaide, South Australia, Australia. robert.casson@adelaide.edu.au
Robert J
RJ
Casson
Shyalle
S
Kahawita
Aimee
A
Kong
James
J
Muecke
Siphetthavong
S
Sisaleumsak
Vithoune
V
Visonnavong
D001251:Astigmatism / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007812:Laos / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000453:epidemiology*; D042262:Retinoscopy; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*