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S.A. Schellini, C.R. Padovani, Sr., C.R. P. Padovani, Sr.; Population–Based Assessment of Refractive Error in a Brazilian Random Sample . Invest. Ophthalmol. Vis. Sci. 2006;47(13):1150.
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© ARVO (1962-2015); The Authors (2016-present)
To assess the prevalence, distribution, and demographic associations of refractive error in a region of Sao Paulo State – Brazil, through a population–based study.
A total of 3354 citizens (6690 eyes) representing a cross–section of the population of two cities located in Sao Paulo State – Brazil were sampled in clusters using a stratified, random, cluster sampling strategy. The sample was selected by a door–to–door household survey in the selected clusters and was invited to participate. All participants were submitted to ophthalmologic exam (visual acuity with and without correction, biomicroscopy, fundoscopy, tonometry, and automated and objective/subjective refraction). Cycloplegic refraction was assessed for participants ≤ 40 years of age and objective and subjective refraction for those aged ≥ 40 years. Myopia was defined as worse than –0.50 D, hyperopia as worse than +0.75 D and astigmatism (simple, hyperopic or myopic astigmatism) worse than 0.50 D. High myopia more than 6.00 D and high hyperopia more than 5 D. Prevalence was evaluated for eyes separately and both together and the data was submitted to statistical analysis.
The age– and gender–standardized prevalence based on cycloplegic refraction showed no refractive error in 33.9% of the evaluated eyes. Hyperopia was detected in 15.2% and high hyperopia in 0.7%. Myopia in 3.6% and high myopia in 0.1%. Hyperopic astigmatism was present in 21.4%, myopic astigmatism in 9.1% and simple astigmatism in 18.8%. Anisometropia of 1 D or more was presented in 1.8% and amblyopia was presented in 0.8% of the eyes. Prevalence of refractive errors differed significantly by age (P < 0.001) but was similar in both sexes. The refractive error correction resulted in normal visual acuity in 60.6% of the eyes, but 3.2% remained with low vision and 2.3% were blind.
The refractive status of the population is provided with documented prevalence of myopia, hyperopia, astigmatism and anisometropia by age and gender, identifying the results obtained when the refractive error correction was done. The data on the distribution and associations of refractive error can be useful for the planning of refractive eye–care services.
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