Cataract, glaucoma leading global causes of blindness in 2020
In this systematic review and analysis, the prevalence of moderate and severe vision impairment (MSVI), defined as presenting visual acuity from <6/18 to 3/60, and blindness, defined as <3/60 or less than 10° visual field around central fixation, were estimated (with 95% uncertainty intervals [UIs]) by cause, age, region, and year. Researchers focused their analysis on individuals aged 50 years and older due to the limited data for individuals at younger ages.
Between 2010 and 2019, the global crude prevalence of avoidable vision impairment and blindness in this population did not change. A decrease of -15·4% in age-standardized prevalence of avoidable blindness was noted, but avoidable MSVI had no change. The number of cases increased for avoidable blindness and MSVI.
Cataract followed by glaucoma were the leading global cause of blindness in 2020 with 1.52 million and 3.6 million cases, respectively. Undercorrected refractive error (2.3 million cases), age-related macular degeneration (1.8 million cases), and diabetic retinopathy (0·86 million cases) rounded out the top 5 global causes.
Undercorrected refractive error and cataract were the leading causes of MSVI with 86.1 million and 78.8 million cases, respectively.
The authors concluded that the “Results suggest eye care services contributed to the observed reduction of age-standardized rates of avoidable blindness but not of MSVI, and that the target in an aging global population was not reached.”
GBD 2019 Blindness and Vision Impairment Collaborators; Vision Loss Expert Group of the Global Burden of Disease Study. Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study. Lancet Glob Health. 2020 Dec 1:S2214-109X(20)30489-7. DOI: 10.1016/S2214-109X(20)30489-7. Epub ahead of print. PMID: 33275949.