At 15 years after enrollment, 22.7% of the participants in the Blue Mountains Eye Study had developed early age-related macular degeneration (AMD), and another 6.8% had late-stage AMD, according to a recent report by this long-running Australian project.1 After adjusting for competing risk of death, the incidence of early and late AMD was 15.1% and 4.1%, respectively.
Consistent with U.S. study. The age-standardized incident rates (13.1% and 3.3% for early and late AMD, respectively) closely matched those that emerged several years ago from another large population-based study in the United States, the Beaver Dam Eye Study, the Australian group reported. Beaver Dam study investigators found 15-year risk-adjusted incidence rates of 14.3% for early AMD and 3.1% for late AMD.2
The consistency between the 2 studies suggests that these estimates of long-term AMD incidence are “robust,” said Blue Mountains Eye Study senior author Jie Jin Wang, MBBS, PhD, professor of epidemiology and a senior research fellow at the University of Sydney Centre for Vision Research. “These long-term observations from an older Australian population provide useful information to understand not only the probabilities of various prognoses of this disease in the next 5, 10, and 15 years but also the factors that are associated with poor prognosis,” he said.
Factors affecting AMD risk. For instance, the researchers confirmed that:
- Current smoking at the time of the baseline exam was a stronger risk factor for developing late AMD than it was for early AMD over a 15-year period.
- After controlling for age, sex, smoking, and AMD genetic susceptibility, late AMD incidence was significantly reduced among persons who ate 1 or more serving of fish per week compared with those who did not eat fish weekly (adjusted odds ratio, 0.48).
- If there was early AMD in one eye at baseline, 67% of the patients developed early AMD in the second eye at some time during the subsequent 15 years.
1 Joachim N et al. Ophthalmology. 2015;122(12):2484-2491.
2 Klein R et al. Ophthalmology. 2007;114(2):253-262.
Relevant financial disclosures— Dr. Wang: None.
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