Changes in visual acuity in a population over a 15-year period: The Beaver Dam Eye Study

center dot PURPOSE: To describe the change in visual acuity in a 15-year period. center dot DESIGN: Population-based study. center dot METHODS: SETTING: Beaver Dam, Wisconsin. PARTICIPANTS: 4068 persons 43 to 86 years of age at the time of a baseline examination in 1988 to 1990, and with follow,up examinations every five years thereafter. SERVATION PROCEDURES: Best-corrected visual acuity after refraction, assessed by a modification of the ETDRS protocol. MAIN OUTCOME MEASURE: Doubling of the visual angle; incidence of visual impairment. center dot RESULTS: Eight percent of the population developed impaired vision (20/40 or worse), 0.8% developed severe visual impairment (20/200 or worse), 7% had doubling of the visual angle, and 2% had improved vision. People 75 years of age or older at baseline were more likely to develop impaired vision (odds ratio [OR] 12.8, 95% confidence interval [CI] 9.6 to 17.1, P < .001), doubling of the visual angle (OR 7.8, 95% CI 5.6 to 10.7, P < .001), and severe visual impairment (OR 20.6, 95% CI 9.5 to 44.8, P < 0.001) compared with people younger than 75 years of age. center dot CONCLUSIONS: These data provide population,based estimates of the cumulative 15-year incidence of loss of vision over a wide spectrum of ages. In people 75 years of age or older the cumulative incidence of visual impairment accounting for the competing risk of death is 25%, of which 4% is severe, indicating a public health problem of considerable proportions as the US population in this age is expected to increase by 55% from 18 million in the year 2005 to 28 million by the year 2025. (Am J Ophthalmol 2006; 142:539-549. (c) 2006 by Elsevier Inc. All rights reserved.)