Rupert R A Bourne1, Seth R Flaxman2, Tasanee Braithwaite3, Maria V Cicinelli4, Aditi Das5, Jost B Jonas6, Jill Keeffe7, John H Kempen8, Janet Leasher9, Hans Limburg10, Kovin Naidoo11, Konrad Pesudovs12, Serge Resnikoff13, Alex Silvester14, Gretchen A Stevens15, Nina Tahhan13, Tien Y Wong16, Hugh R Taylor17. 1. Vision & Eye Research Unit, Anglia Ruskin University, Cambridge, UK. Electronic address: rb@rupertbourne.co.uk. 2. Department of Statistics, University of Oxford, Oxford, UK. 3. Vision & Eye Research Unit, Anglia Ruskin University, Cambridge, UK. 4. San Raffaele Scientific Institute, Milan, Italy. 5. Health Education England (Yorkshire and the Humber), Leeds, UK. 6. Department of Ophthalmology, Universitätsmedizin, Mannheim, Germany; Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. 7. L V Prasad Eye Institute, Hyderabad, India. 8. Immunology and Uveitis Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA; Discovery Eye Center, MyungSung Christian Medical Center, Addis Ababa, Ethiopia. 9. Nova Southeastern University, Fort Lauderdale, FL, USA. 10. Health Information Services, Grootebroek, Netherlands. 11. African Vision Research Institute, University of Kwazulu-Natal, Durban, South Africa; Brien Holden Vision Institute, Sydney, NSW, Australia. 12. NHMRC Centre for Clinical Eye Research, Flinders University, Adelaide, SA, Australia. 13. Brien Holden Vision Institute, Sydney, NSW, Australia; School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia. 14. St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK. 15. Department of Information, Evidence and Research, World Health Organization, Geneva, Switzerland. 16. Singapore Eye Research Institute, Duke-NUS Graduate Medical School, National University of Singapore, Singapore. 17. Melbourne School of Population Health, University of Melbourne, Carlton, VIC, Australia.
Abstract
BACKGROUND: Global and regional prevalence estimates for blindness and vision impairment are important for the development of public health policies. We aimed to provide global estimates, trends, and projections of global blindness and vision impairment. METHODS: We did a systematic review and meta-analysis of population-based datasets relevant to global vision impairment and blindness that were published between 1980 and 2015. We fitted hierarchical models to estimate the prevalence (by age, country, and sex), in 2015, of mild visual impairment (presenting visual acuity worse than 6/12 to 6/18 inclusive), moderate to severe visual impairment (presenting visual acuity worse than 6/18 to 3/60 inclusive), blindness (presenting visual acuity worse than 3/60), and functional presbyopia (defined as presenting near vision worse than N6 or N8 at 40 cm when best-corrected distance visual acuity was better than 6/12). FINDINGS: Globally, of the 7·33 billion people alive in 2015, an estimated 36·0 million (80% uncertainty interval [UI] 12·9-65·4) were blind (crude prevalence 0·48%; 80% UI 0·17-0·87; 56% female), 216·6 million (80% UI 98·5-359·1) people had moderate to severe visual impairment (2·95%, 80% UI 1·34-4·89; 55% female), and 188·5 million (80% UI 64·5-350·2) had mild visual impairment (2·57%, 80% UI 0·88-4·77; 54% female). Functional presbyopia affected an estimated 1094·7 million (80% UI 581·1-1686·5) people aged 35 years and older, with 666·7 million (80% UI 364·9-997·6) being aged 50 years or older. The estimated number of blind people increased by 17·6%, from 30·6 million (80% UI 9·9-57·3) in 1990 to 36·0 million (80% UI 12·9-65·4) in 2015. This change was attributable to three factors, namely an increase because of population growth (38·4%), population ageing after accounting for population growth (34·6%), and reduction in age-specific prevalence (-36·7%). The number of people with moderate and severe visual impairment also increased, from 159·9 million (80% UI 68·3-270·0) in 1990 to 216·6 million (80% UI 98·5-359·1) in 2015. INTERPRETATION: There is an ongoing reduction in the age-standardised prevalence of blindness and visual impairment, yet the growth and ageing of the world's population is causing a substantial increase in number of people affected. These observations, plus a very large contribution from uncorrected presbyopia, highlight the need to scale up vision impairment alleviation efforts at all levels. FUNDING: Brien Holden Vision Institute.
BACKGROUND: Global and regional prevalence estimates for blindness and vision impairment are important for the development of public health policies. We aimed to provide global estimates, trends, and projections of global blindness and vision impairment. METHODS: We did a systematic review and meta-analysis of population-based datasets relevant to global vision impairment and blindness that were published between 1980 and 2015. We fitted hierarchical models to estimate the prevalence (by age, country, and sex), in 2015, of mild visual impairment (presenting visual acuity worse than 6/12 to 6/18 inclusive), moderate to severe visual impairment (presenting visual acuity worse than 6/18 to 3/60 inclusive), blindness (presenting visual acuity worse than 3/60), and functional presbyopia (defined as presenting near vision worse than N6 or N8 at 40 cm when best-corrected distance visual acuity was better than 6/12). FINDINGS: Globally, of the 7·33 billion people alive in 2015, an estimated 36·0 million (80% uncertainty interval [UI] 12·9-65·4) were blind (crude prevalence 0·48%; 80% UI 0·17-0·87; 56% female), 216·6 million (80% UI 98·5-359·1) people had moderate to severe visual impairment (2·95%, 80% UI 1·34-4·89; 55% female), and 188·5 million (80% UI 64·5-350·2) had mild visual impairment (2·57%, 80% UI 0·88-4·77; 54% female). Functional presbyopia affected an estimated 1094·7 million (80% UI 581·1-1686·5) people aged 35 years and older, with 666·7 million (80% UI 364·9-997·6) being aged 50 years or older. The estimated number of blind people increased by 17·6%, from 30·6 million (80% UI 9·9-57·3) in 1990 to 36·0 million (80% UI 12·9-65·4) in 2015. This change was attributable to three factors, namely an increase because of population growth (38·4%), population ageing after accounting for population growth (34·6%), and reduction in age-specific prevalence (-36·7%). The number of people with moderate and severe visual impairment also increased, from 159·9 million (80% UI 68·3-270·0) in 1990 to 216·6 million (80% UI 98·5-359·1) in 2015. INTERPRETATION: There is an ongoing reduction in the age-standardised prevalence of blindness and visual impairment, yet the growth and ageing of the world's population is causing a substantial increase in number of people affected. These observations, plus a very large contribution from uncorrected presbyopia, highlight the need to scale up vision impairment alleviation efforts at all levels. FUNDING: Brien Holden Vision Institute.
Authors: Daniel T Gray; Nicole M De La Peña; Lavanya Umapathy; Sara N Burke; James R Engle; Theodore P Trouard; Carol A Barnes Journal: J Neurosci Date: 2020-10-13 Impact factor: 6.167