Prevalence and Causes of Vision Impairment and Blindness in Older Adults in Brazil: The S√£o Paulo Eye Study
Salomao, S. R., Cinoto, R. W., Berezovsky, A., Araujo-Filho, A., Mitsuhiro, M. R., Mendieta, L., Morales, P. H., Pokharel, G. P., Belfort, R., Ellwein, L. B.
The purpose of this study is to Investigate prevalence and causes of vision impairment/blindness in older adults in a low-middle income area of São Paulo, Brazil.
Cluster sampling, based on geographically defined census sectors, was used in randomly selecting cross-sectionally persons 50 years of age or older. Subjects were enumerated through a door-to-door survey and invited for measurement of presenting and best-corrected visual acuity and an ocular examination. The principal cause was identified for eyes with presenting visual acuity less than 20/32.
A total of 4,224 eligible persons in 2,870 households were enumerated, and 3,678 (87.1%) examined.
The prevalence of presenting visual acuity ≥20/32 in both eyes was 61.6% (95% confidence interval [CI]: 59.4%–63.9%), and 80.4% (95% CI: 78.8%–82.1%) with best correction.
The prevalence of visual impairment (<20/63 to ≥20/200) in the better eye was 4.74% (95% CI: 3.97%–5.53%), and 2.00% (95% CI: 1.52%–2.49%) with best correction.
The prevalence of presenting bilateral blindness (<20/200) was 1.51% (95% CI: 1.20%–1.82%), and 1.07% (95% CI: 0.79%–1.35%) with best correction.
Presenting blindness was associated with older age and lack of schooling. Retinal disorders (35.3%) and cataract (28.3%) were the most common causes of blind eyes.
Cataract (33.2%), refractive error (32.3%), and retinal disorders (20.3%) were the main causes of vision impairment <20/63 to ≥20/200, with refractive error (76.8%) and cataract (12.2%) as main causes for eyes with acuity <20/32 to ≥20/63.
Vision impairment is a significant problem in older Brazilians reinforcing the need to implement prevention of blindness programs for elderly people with emphasis on those without schooling.