Fifteen-Year Cumulative Incidence of Age-Related Macular Degeneration: The Beaver Dam Eye Study
Received 7 June 2006; accepted 26 October 2006.
Purpose
To describe the 15-year cumulative incidence of signs of early and late age-related macular degeneration (AMD).
Design
Population-based cohort study.
Participants
We included 3917 persons, 43 to 86 years of age at the time of a baseline examination in 1988 through 1990 and with information collected in follow-up in 1993 through 1995, and/or 1998 through 2000, and/or 2003 through 2005.
Methods
Grading of stereoscopic fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.
Main Outcome Measures
Cumulative incidence of drusen type and size, pigmentary abnormalities, geographic atrophy, and exudative AMD accounting for competing risk of death.
Results
The 15-year cumulative incidence was 14.3% for early AMD (the presence of either soft indistinct drusen or the presence of pigmentary abnormalities together with any type of drusen) and 3.1% for late AMD (presence of exudative AMD or geographic atrophy). There was an increased incidence of AMD lesions with age (P<0.05). Individuals ≥ 75 years of age at baseline had significantly (P<0.01) higher 15-year incidences of the following characteristics than people 43 to 54 years of age: larger drusen (125 μm in diameter, 24.1% vs 10.6%), soft indistinct drusen (18.7% vs 6.5%), retinal pigmentary abnormalities (20.2% vs 3.7%), exudative macular degeneration (4.4% vs 0.4%), and pure geographic atrophy (3.2% vs 0%). Controlling for age, compared with those with small numbers of only small hard drusen (1–2), those with large numbers of only hard drusen (≥8) had an increased 15-year age-adjusted incidence of both soft indistinct drusen (16.3% vs 4.7%) and pigmentary abnormalities (10.6% vs 2.7%). Eyes with soft indistinct drusen or pigmentary abnormalities at baseline were more likely to develop late AMD at follow-up than eyes without these lesions (17.8% vs 1.2% and 12.9% vs 1.7%, respectively).
Conclusions
We document the long-term incidence of signs of AMD and a continuum from small hard drusen to late AMD in older persons in the population. The 15-year cumulative incidence of late AMD in people ≥ 75 years of age (8%) indicates a public health problem of significant proportions because the United States population this age is expected to increase by 54% between 2005 and 2025.
1Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
2Department of Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Correspondence to Ronald Klein, MD, MPH, Department of Ophthalmology and Visual Sciences, University of Wisconsin—Madison, 610 North Walnut Street, 417 WARF, Madison, WI 53726-2336.
Manuscript no. 2006-616.
None of the authors has a proprietary interest in the material presented herein.
Supported by the National Institutes of Health, Bethesda, Maryland (grant no. EY06594 [RK, BEKK]), and, in part, Research to Prevent Blindness, New York, New York (Senior Scientific Investigator awards [RK, BEKK]). The National Eye Institute, Bethesda, Maryland, provided funding for the entire study, including collection and analyses of data; Research to Prevent Blindness provided further support for data analyses.
ABSTRACT