Functional Low Vision in Adults from Latin America: Findings from Population-Based Surveys in 15 Countries

  • The objective of the study is to review data on functional low vision (FLV) (low vision—visual acuity (VA) < 6/18 (<20/60) to ≥ perception of light (PL+) in the better eye—that is untreatable and uncorrectable) in adults aged 50 years or older from published population-based surveys from 15 countries in Latin America and the Caribbean.

  • Despite major advances in eye care in recent decades, an increasing number of people have functional low vision (FLV) (low vision—visual acuity (VA) < 6/18 (<20/60) to ≥ perception of light (PL+) in the better eye—that is untreatable and uncorrectable).><20/60 to ≥ perception of light (PL+) in the better eye – that is untreatable an uncorrectable).

  • 10 national and five subnational cross-sectional, population-based surveys on blindness and visual impairment covering 55,643 people from 2003 to 2013 were reanalyzed to extract statistics on FLV.

  • Eleven of the studies used the rapid assessment of avoidable blindness (RAAB) method and four used the rapid assessment of cataract surgical services (RACSS) method.

  • For the 10 national surveys, age and sex-specific prevalence of FLV was extrapolated against the corresponding population to estimate the total number of people ≥ 50 years old with FLV.

  • Age- and sex-adjusted prevalence of FLV in people ≥ 50 years old ranged from 0.9% (Guatemala, Mexico, and Uruguay) to 2.2% (Brazil and Cuba) and increased by age.

  • The weighted average prevalence for the 10 national surveys was 1.6%: 1.4% in men and 1.8% in women. For all 10 national studies, a total of 509 164 people ≥ 50 years old were estimated to have FLV.

  • Based on the 910 individuals affected, the main causes of FLV were age-related macular degeneration (weighted average prevalence of 26%), glaucoma (23%), diabetic retinopathy (19%), other posterior segment disease (15%), non-trachomatous corneal opacities (7%), and complications after cataract surgery (4%).

  • The study concluded that FLV is expected to rise because of 1) the exponential increase of this condition by age, 2) increased life expectancy, and 3) the increase in people ≥ 50 years old.

  • These data can be helpful in planning and developing low vision services for the region; large countries such as Brazil and Mexico would need more studies. Prevention is a major strategy to reduce FLV, as more than 50% of it is preventable.

Publication date

November 5, 2018


Pan American Journal of Public Health

Sponsor Institution

Pan-american Health Organization (PAHO), Vision 2020 Latin America and UNESCO, Orbis International


Hans Limburg, Rosario Espinoza, Van C. Lansingh, and Juan Carlos Silva
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