Cardiovascular Risk Factors and the Long-term Incidence of Age-Related Macular Degeneration: The Blue Mountains Eye Study
Received 10 July 2006; accepted 26 September 2006. published online 31 January 2007.
Purpose
To assess the relationship between cardiovascular disease and cardiovascular risk factors, other than smoking, and risk of long-term incident age-related macular degeneration (AMD).
Design
Population-based cohort study.
Participants
There were 3654 baseline (1992–1994) participants aged ≥ 49 years included in the Blue Mountains region, west of Sydney, Australia. Of these, 2335 (75% of survivors) were reexamined after 5 years (1997–1999) and 1952 (76% of survivors) after 10 years (2002–2004).
Methods
Stereoscopic color fundus photographs were graded using the Wisconsin Age-related Maculopathy Grading System. History, physical examination, and fasting blood samples provided data on possible risk factors. Age-related macular degeneration incidence was calculated using the Kaplan–Meier survival approach. Discrete linear logistic models were used to assess risk of incident AMD. Relative risks (RR) and 95% confidence intervals (CI) are presented after adjusting for age, gender, smoking, and other risk factors.
Main Outcome Measure
Incident early and late AMD.
Results
Increasing high-density lipoprotein (HDL) cholesterol was inversely related to incident late AMD (RR per standard deviation [SD] increase, 0.74; 95% CI, 0.56–0.99). Elevated total/HDL cholesterol ratio predicted late AMD (RR per SD increase, 1.35; 95% CI, 1.07–1.70) and geographic atrophy (GA; RR per SD, 1.63; 95% CI, 1.18–2.25). Diabetes predicted incident GA (RR, 3.89; 95% CI, 1.36–11.08), but not neovascular AMD. History of stroke (RR 2.01; 95% CI, 1.12–3.58), or any cardiovascular disease (stroke, myocardial infarction, or angina; RR, 1.57; 95% CI, 1.13–2.16) predicted incident early AMD and incident indistinct soft or reticular drusen (RR, 2.38; 95% CI, 1.33–4.27 for stroke; RR, 1.80; 95% CI, 1.28–2.52 for any cardiovascular disease). Neither pulse pressure, systolic or diastolic blood pressure, or presence of hypertension at baseline were associated with incident AMD.
Conclusions
Our findings provide some evidence of links between cardiovascular risk factors and AMD. Further prospective evaluation of these relationships is warranted, as these findings could have therapeutic implications.
1Centre for Vision Research, Department of Ophthalmology, Westmead Millennium Institute, University of Sydney, Westmead, Australia.
2Centre for Clinical Epidemiology and Biostatistics, University of Newcastle, Newcastle, Australia.
Correspondence to Dr Jie Jin Wang, Centre for Vision Research, Department of Ophthalmology, University of Sydney, Westmead Hospital, Hawkesbury Road, Westmead, NSW, Australia, 2145.
Manuscript no. 2006-752.
Supported by the National Health and Medical Research Council, Canberra, Australia (grant nos. 974159, 211069), and Vision Co-operative Research Centre, Sydney, Australia.
ABSTRACT