Abstract
Purpose::
While reticular drusen (RD) have been reported to be associated with a high risk of incident late age-related macular degeneration (AMD), little is known regarding its epidemiology. The purpose of the study was to describe the prevalence and 15-year cumulative incidence of and risk factors for RD, a sign of early AMD, and its association with late AMD.
Methods::
4,926 persons, 43-86 years of age at the time of a baseline examination in 1988-1990, living in Beaver Dam, Wisconsin, of whom 3,684 participated in a 5-year follow-up examination, 2,764 participated in a 10-year follow-up, and 2,119 participated in a 15-year follow-up. Characteristics of RD and other lesions typical of AMD were determined by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.
Results::
The prevalence at baseline and the 15-year cumulative incidence in either eye of RD was 0.6% and 2.5%, respectively. There was an increased incidence of RD with age, varying from 0.4% in those 43-54 years of age to 5.2% in those 75 years or older at baseline (p<0.001). The prevalence was higher in those homozygous (CC, 1.2%) or heterozygous (TC,1.0%) for CFH gene polymorphism Y402H (12775T to C) than in those without this polymorphism (TT, 0.1%, age-adjusted p=.04). While controlling for age, risk factors associated with increased risk of RD included being female (OR 3.1, 95% CI 1.7-5.6), current smoking (OR vs never 2.3, 95% CI 1.2, 4.4, p=.01), while drinking wine (OR 0.5, 95% CI 0.3, 0.7), and use of hormone replacement therapy [HRT] in women (OR 0.7, 95% CI 0.5, 1.0) were associated with decreased risk. Eyes with RD at baseline had higher cumulative incidence of geographic atrophy (26%) than eyes without soft drusen (1%), eyes with soft distinct [SD] drusen (1%), or eyes with soft indistinct [SI] drusen (7%) and had higher cumulative incidence of exudative AMD (19%) compared to eyes without soft drusen (0%), eyes with SD drusen (3%), and eyes with SI drusen (10%).
Conclusions::
These population-based estimates document the low prevalence and long-term cumulative incidence of RD and show its association with modifiable risk factors, smoking, drinking, and use of HRT. While relatively infrequent, the presence of RD is of importance because of increased risk for incidence of late AMD.
Keywords: age-related macular degeneration • drusen • clinical (human) or epidemiologic studies: prevalence/incidence