Joao M Furtado

The Brazilian Amazon Region Eye Survey: Design and Methods

ABSTRACT Purpose: To describe the study design, operational strategies, procedures, and baseline characteristics of the Brazilian Amazon Region Eye Survey (BARES), a population-based survey of the prevalence and causes of distance and near visual impairment and blindness in older adults residing in the city of Parintins. Methods: Cluster sampling, based on geographically defined census sectors, was used for cross-sectional random sampling of persons 45 years and older from urban and rural areas. Subjects were enumerated through a door-to-door survey and invited for measurement of uncorrected, presenting and best-corrected visual acuity and an ocular examination. Results: Of 9931 residents (5878 urban and 4053 rural), 2384 individuals (1410 urban and 974 rural) were eligible and 2041 (1180 urban and 861 rural) had a clinical examination (response rate 85.6%). The majority of participants were female (1041, 51.0%); the average age was 59.9 ± 11.1 years (60.2 ± 11.2 years for urban and 59.4 ± 11.1 years for rural); 1360 (66.6%) had primary schooling or less (58.1% in urban and 78.4% in rural) and 57.8% were resident in urban areas. The age distribution between sexes was similar (p = 0.178). Both sex and age distributions of the sample were comparable to that of the Brazilian Amazon Region population. Conclusions: The BARES cohort will provide information about the prevalence and causes of near and distance vision in this underprivileged and remote population in Brazil.

Presbyopia and Ocular Conditions Causing Near Vision Impairment in Older Adults From the Brazilian Amazon Region

PURPOSE To investigate the prevalence and causes of near vision impairment (NVI) in a population of older adults from the Brazilian Amazon Region. DESIGN Population-based cross-sectional study. METHODS Cluster sampling was used in randomly selecting subjects 45 years of age and older from urban and rural areas of Parintins city, Brazil. Participants underwent ophthalmic examination, including uncorrected (UCNVA), presenting (PNVA), and best-corrected near visual acuity (BCNVA) from each eye; biomicroscopy; funduscopy; and subjective refraction, including testing with additional lenses for near vision optical correction. A principal cause for NVI was assigned by the ophthalmologist and presbyopia was defined as UCNVA ≤ 20/40 changing to > 20/40 with BCNVA. Free-of-charge glasses were provided for those in need. RESULTS A total of 2384 subjects were enumerated and 2025 had reliable NVA measurements from both eyes. The prevalence of NVI in the better-seeing eye was 96.5% with UCNVA, decreasing to 81.1% with PNVA and to 20.5% with BCNVA. Presbyopia was the principal cause of NVI in 71.8%, followed by cataract (16.5%) and pterygium (2.5%), and was associated with younger age and high schooling. Glasses for near vision were prescribed and provided to 1414 (69.8%) participants. CONCLUSIONS A high prevalence of NVI was detected even in those wearing glasses for near. Prescription and provision of low-cost reading glasses should be considered by Brazilian health authorities to address this easily and promptly correctable form of vision impairment.