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.

KEYWORDS:

• Adults
• baseline characteristics
• blindness
• Brazilian Amazon
• methodology
• population-based study
• visual impairment

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the writing and content of this article.

Funding

Financial support for this study was received from: Conselho Nacional de Pesquisa e Desenvolvimento Tecnológico, CNPq, Brasilia, Brasil, Science Without Borders grant #402120/2012-4 to SRS (Visiting Professor Scholarship to SM, post-doctoral scholarship to JMF), research scholarship to SRS and RBJ; Lions Club International Foundation, Sight First Grant #SF1758/UND to SRS; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Research Grant #2013/16397-7 to SRS.

Additional information

Funding

Financial support for this study was received from: Conselho Nacional de Pesquisa e Desenvolvimento Tecnológico, CNPq, Brasilia, Brasil, Science Without Borders grant #402120/2012-4 to SRS (Visiting Professor Scholarship to SM, post-doctoral scholarship to JMF), research scholarship to SRS and RBJ; Lions Club International Foundation, Sight First Grant #SF1758/UND to SRS; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Research Grant #2013/16397-7 to SRS.