Abstract
Purpose: :
To evaluate the association of carotid artery atherosclerosis and the 5-yr incidence of age-related macular degeneration (AMD).
Methods: :
The 5-yr incidence of AMD was measured from 30° color stereoscopic fundus photographs taken as part of the Beaver Dam Eye Study (1998-2000 and 2003-2005). The carotid artery intima-media thickness (IMT) and presence of plaque were assessed by B-mode ultrasonography during the 1998-2000 examination for the Epidemiology of Hearing Loss Study in the same cohort. The presence of plaque at each of three sites in the carotid artery (common, bifurcation, and internal) was summed for right and left sides (score 0-6). Participants without AMD in 1998-2000 who had carotid ultrasound images were included in these analyses (n=1525, ages 53-93 yrs).
Results: :
The mean IMT was 1.49 mm and 66% of the participants had some carotid artery plaque. Having plaque in the carotid artery was associated with the 5-yr incidence of AMD (age-sex adjusted Odds Ratio (OR) for 4-6 sites vs none = 2.3; 95% Confidence Interval (CI) = 1.1, 4.8). IMT was marginally related to the 5-year incidence of AMD (OR 3rd tertile vs 1st tertile = 1.9; 95%CI= 1.0, 3.6). Further adjustment for cardiovascular risk factors (smoking, obesity, and cholesterol) only slightly attenuated these risk estimates. In sex-specific analyses, adjusting for age, IMT was associated with increased risk of pure geographic atrophy (OR per 0.5 mm = 1.5; 95%CI=1.1, 2.2) and late AMD (OR=1.5; 95%CI=1.1, 1.9) among men but was not associated with these outcomes in women (OR=1.0 and OR=1.0, respectively).
Conclusions: :
These data are consistent with other studies showing that severity of atherosclerosis may contribute to the development of AMD, and suggest that reducing atherosclerotic risk factors may decrease the risk of AMD.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: risk factor assessment