Regional Disparities in Prevalence and Causes of Visual Impairment and Blindness, Cataract Surgical Coverage and Ocular Findings in Adults 50 Years and Older in Brazil: A Comparative Analysis between Two Population-Based Cross-Sectional Surveys Performed Within a 10-Year Interval

ABSTRACT

Purpose

To investigate disparities in the prevalence and causes of visual impairment and blindness, cataract surgical coverage, and ocular findings in older adults from two Brazilian geo-socio-demographic areas, São Paulo and Parintins cities.

Methods

Data from two population-based studies including participants 50 years and older from the cities of São Paulo (São Paulo Eye Study – SPES, 2004) and Parintins (Brazilian Amazon Region Eye Survey – BARES, 2014) were aggregated.

Results

A total of 5318 participants (3677 from SPES;1641 from BARES) were included. The prevalence of severe visual impairment (SVI) and blindness were, respectively, 0.74% (0.46–1.02) and 0.77% (0.48–1.05) in SPES and 1.72% (1.09–2.35) and 3.44% (2.55–4.33) in BARES. SVI and blindness were associated with BARES study [OR = 2.27 (1.30–3.95); p = .004 - SVI] [OR:4.07 (2.51–6.60); p < .001- blindness]; and older age [OR = 10.93 (4.20–28.45); p < .001 - SPES; OR = 17.96 (8.75–36.83); p < .001 - BARES] while higher education level was a protective factor [OR = 0.21 (0.05–0.95) - SPES; p = .042; OR = 0.21 (0.05–0.91); p = .037 - BARES]. Cataract was the main cause of bilateral severe visual impairment (25.93% in SPES and 64.29% in BARES) and bilateral blindness (21.43% in SPES and 35.71% in BARES). Cataract surgical coverage was significantly lower in BARES (36.32%) compared to SPES (57.75%).

Conclusion

The prevalence of SVI and blindness was three times higher in older adults from the Brazilian Amazon compared to those living in São Paulo city, despite a 10-year interval between the two studies. These disparities should be mitigated by initiatives to promote access to eye care services targeting underprivileged and remote Brazilian areas.

KEYWORDS:

• Blindness
• disparities
• population-based
• prevalence
• visual impairment

ACKNOWLEDGMENTS

The authors thank Marcos Jacob Cohen, M.D. and Mauro Campos, M.D. for their invaluable contribution to fieldwork; Mrs. Bruna Colussi Cypel for building illustrations.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

STATEMENT

This submission has not been published anywhere previously and has not simultaneously been considered for any other publication.

Additional information

Funding

For the São Paulo Eye Study: World Health Organization, Geneva, Switzerland (under National Institutes of Health [Bethesda, Maryland] contract no. N01-EY-2103); Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP (São Paulo, SP, Brazil), grant # 2004/06670-9 to SRS. For the Brazilian Amazon Region Eye Survey (BARES): Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq, Brasilia; grant 402120/2012-4 to S.R.S., S.M., and J.M.F.; Fundação de Amparo à Pesquisa do Estado de São Paulo, São Paulo, Brasil grant 2013/16397-7 to S.R.S.; SightFirst Program, Lions Club International Foundation grant 1758 to S.R.S.; Instituto da Visão-IPEPO, São Paulo, SP, Brasil; Fundação Piedade Cohen, Manaus, Amazonas, Brasil; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil finance code 001 (post-doctoral scholarship to S.S.W.; and pre-doctoral scholarship to A.G.F.).