Indigenous eye health in the Americas: the burden of vision impairment and ocular diseases

Author: Furtado JM, Fernandes AG, Silva JC, Pino SD, Hommes C.

Geographical coverage: Brazil, Paraguay, United States of America (USA), Canada, Colombia, Mexico, Venezuela, Ecuador, Haiti.

Sector: Burden of disease

Sub-sector: Prevalence

Equity focus: Indigenous People

Study population: Indigenous People with cataract, under-corrected refractive error, glaucoma, age-related macular degeneration, diabetic retinopathy pterygium, trachoma, and onchocerciasis.

Review type: Effectiveness review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background

Vision impairment and blindness affect over 339 million people globally, with 43.3 million classified as blind and 295.3 million experiencing moderate to severe visual impairment (MSVI). In the Americas, estimates of blindness vary from 1.93 cases per 1,000 people in southern Latin America to 7.40 cases per 1,000 in tropical Latin America. Global estimates frequently exclude data from Indigenous Peoples and other minority ethnic groups, leading to potential underestimation of the burden and insufficient public health strategies for these communities.

Objective

To review the burden of vision impairment, blindness, and ocular disease in Indigenous Peoples of the Americas compared to non-Indigenous populations and to identify gaps in the literature.

Main findings

Overall, authors found a clear difference in frequencies of vision impairment and blindness between high-income North America and tropical Latin America countries.

The review included 32 studies: 14 (43.75%) from tropical Latin America (13 in Brazil, 1 in Paraguay), 12 (37.5%) from high-income North America (8 USA, 4 Canada), 4 (12.5%) from central Latin America (2 Colombia, 1 Mexico, 1 Venezuela), 1 (3.12%) from Andean Latin America (Ecuador), and 1 (3.12%) from the Caribbean (Haiti). No studies were found from southern Latin America.

Eleven studies (34.37%) reported frequencies of vision impairment and blindness, mostly from high-income North America. No data were reported from Andean Latin America, the Caribbean, or southern Latin America. Vision acuity measurement methods and definitions of vision impairment and blindness varied widely.

Despite these differences, the frequency of vision impairment and blindness was clearly higher in tropical Latin America (28.5%) than in high-income North America (11.1%) for adults over 40 years, based on BCVA.

Ocular disease frequencies were reported in 26 studies (81.25%), mainly from tropical Latin America and high-income North America. Trachoma was discussed in 9 studies (34.61%), cataract in 7 (26.92%), diabetic retinopathy in 6 (23.07%), and pterygium in 5 (19.23%). Disease frequencies varied across regions and Indigenous groups.

Methodology

The authors included studies published between January 2000 and November 2022 reporting on frequencies of vision impairment, blindness, or ocular diseases among Indigenous populations in the Americas. No language restrictions were applied. Screening and data extraction were based on eligibility criteria, and results were reported using descriptive synthesis aligned with the Global Burden of Disease (GBD) regional classifications.

Applicability/external validity

The review did not explicitly discuss generalisability. However, the limited representation of studies from southern and Andean Latin America raises concerns about the applicability of findings across the entire region.

Geographic focus

Studies were conducted in Brazil, Paraguay, USA, Canada, Colombia, Mexico, Venezuela, Ecuador, and Haiti.

Summary of quality assessment

There is low confidence in the review’s conclusions due to key methodological limitations. The databases searched, the number of reviewers involved, and whether risk of bias was assessed were not reported.