ArticleBMJ open2022
Cross-sectional study investigating the prevalence and causes of vision impairment in Northwest Portugal using capture-recapture.
Article in BMJ open, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
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3 citing papers in PubMed, 5 citations in OpenAlex.
- Perceived stress levels among patients treated for neovascular age-related macular degeneration with anti-VEGF injections.Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie · 2025Article
- The Basic VRS-Effect Study: Clinical Trial Outcomes and Cost-Effectiveness of Low Vision Rehabilitation in Portugal.Ophthalmology and therapy · 2023Article
- Predictors of problems reported on the EQ-5D-3L dimensions among people with impaired vision in northern Portugal.Health and quality of life outcomes · 2022Observational
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Authors and funding
6 authors at 5 institutions in 3 countries.
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No grant is acknowledged in the PubMed record.
Abstract
objectivesThe aim of this study was to estimate the prevalence and causes of vision impairment (VI) in Portugal.
settingInformation about people with VI was obtained from primary care centres, blind association (ACAPO) and from hospitals (the PCVIP study) in the Northwest of Portugal during a period spanning years 2014-2015. Causes of VI were obtained from hospitals.
participantsAdministrative and medical records of people with visual acuity in the better seeing eye of 0.5 decimal (0.30logMAR) or worse and/or visual field less than 20° were investigated. Capture-recapture with log-linear models was applied to estimate the number of individuals missing from lists of cases obtained from available sources. PRIMARY AND SECONDARY OUTCOME MEASURES: Log-linear models were used to estimate the crude prevalence and the category specific prevalence of VI.
resultsCrude prevalence of VI was 1.97% (95% CI 1.56% to 2.54%), and standardised prevalence was 1% (95% CI 0.78% to 1.27%). The age-specific prevalence was 3.27% (95% CI 2.36% to 4.90%), older than 64 years, 0.64% (95% CI 0.49% to 0.88%), aged 25-64 years, and 0.07% (95% CI 0.045% to 0.13%), aged less than 25 years. The female-to-male ratio was 1.3, that is, higher prevalence among females. The five leading causes of VI were diabetic retinopathy, cataract, age-related macular degeneration, glaucoma and disorders of the globe.
conclusionsThe prevalence of VI in Portugal was within the expected range and in line with other European countries. A significant number of cases of VI might be due to preventable cases and, therefore, a reduction of the prevalence of VI in Portugal seems possible. Women and old people were more likely to have VI and, therefore, these groups require extra attention. Future studies are necessary to characterise temporal changes in prevalence of VI in Portugal.
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