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Larissa H. Satto, Fabio H. Ferraz, Paula OPromolla, Silvana A. Schellini; Random Sampling Of The Brazilian Population For Visual Acuity: Refraction Impingement Based On Low Visual Acuity And Blindness Decrease. Invest. Ophthalmol. Vis. Sci. 2012;53(14):3607.
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© ARVO (1962-2015); The Authors (2016-present)
To verify the Brazilian population presenting visual and pursuant optical correction, assess the refraction impingement based on low visual acuity and blindness decrease.
A cross-sectional and prospective study, carried out in 9 cities in the center-west region of São Paulo state, Brazil, utilizing a mobile ophthalmology bus. The 8000 sample-population was estimated, based on domicile random and systematic sampling and IBGE-Brazil census data base. The presenting Visual Acuity (VA) was evaluated in individuals without corrective lenses and with eyeglasses when existing. In a subgroup whereat the VA is different from zero logMAR cycloplegic refraction was realized, and the best corrected VA (BCVA) assessment was carried out. The inclusion criteria was children older than one year, not institutionalized and permanent townspeople. The exclusion criteria was people who had had undergone cataract surgery or refractive surgery previously. Was recorded on file merely the right eye data assessment, and considered the left eye merely when not available the VA from the right eye by a limiting affection. Statistical analysis was perfomed using a commercially available statistical software package (SPSS for Windows, version 15, SPSS Inc., Chicago, IL).
The VA was reached in 96.18% of the sample. Analyzing the presenting vision with no corrective lenses 67.5% showed VA ≥ 0.15 logMAR, 14.8% 0.15 > VA ≥ 0.5 logMAR, 9.8% 0.5 logMAR > VA ≥ 1.3 logMAR and 4.1% VA ≤ 1.3 logMAR. Pursuant best optical correction vision, the frequency sample for VA ≥ 0.15 logMAR increase to 80.7%; from people with VA ≥ 0.15 logMAR, 67.3% coming from the value below (0.15 logMAR > VA ≥ 0.5 logMAR). Still keep the optical correction, 70.3% of the sample showing 0.15 logMAR > VA ≥ 0.5 logMAR these showing VA level previous corrective lenses uses, keeping the same as before. All remain 0.5 logMAR > AV ≥ 1.3 logMAR and AV < 1.3 logMAR), was observed that majority keep the same VA level, achieving 99% of the sample with the same acuity ≤ 1.3 logMAR. The optical correction was not enough to re-establish the vision in 4.9% of the sample.
The improvement potential for the VA is lower if compare with VA ≤ 0.5 logMAR. This event could be related with the major advanced and limiting chronic-degenerative pathology for those samples.
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