Abstract
Abstract: :
Purpose: To determine the prevalence of clinically significant cataract, cataract surgery and related visual disability in the United States, and to estimate the change in these prevalence figures over the next 20 years. Methods: Summary prevalence estimates of clinically significant cataract, cataract surgery, cataract-related low vision and cataract-related blindness were prepared separately for blacks, whites and Hispanics in 5-year age intervals starting at 40 years. The estimates were based on standardized cutoffs (cortical ≷ 25% of lens, PSC ≷= 1mm, nuclear ≷= the penultimate grade in the system used, visual disability < 20/40 in the better eye, blindness <= 20/200 in the better eye) applied to data from major population-based studies in the US, and, where appropriate, Australia and Barbados. These rates were applied to 2000 US census data, and projected population figures for 2010 and 2020. The project was carried out in conjunction with Prevent Blindness America and the National Eye Institute, and with the support of investigators from the Barbados Eye Study, Beaver Dam Eye Study, Blue Mountains Eye Study, Melbourne Visual Impairment Project, Proyecto VER, and the Salisbury Eye Evaluation. Results: An estimated 21.1 million Americans over the age of 40 have clinically significant cataract in either eye, with 6.2 million having undergone cataract surgery, a crude surgical prevalence of 5.2%. The total number of persons with clinically significant cataract is estimated to rise to 33.4 million by 2020, during which time the total with previous cataract surgery will rise to 10.0 million and will double among Hispanics. Prevalence data for visual disability and blindness due to cataract, and for the different clinical sub-types of lens opacity, will also be presented for the different races. Conclusion: Cataract is an important cause of visual disability in the United States. The number of persons having undergone cataract surgery is expected to rise by 60% over the next 20 years.
Keywords: 338 cataract • 354 clinical (human) or epidemiologic studies: prevalence/incidence • 309 aging