Four-Year Incidence and Risk Factors of Age-Related Macular Degeneration: the ALIENOR Study

Abstract

Purpose : Few population-based prospective studies of age-related macular degeneration (AMD) have been conducted in Europe. The objective was to describe the 4-year cumulative incidence and associated risk factors of AMD in French elderly subjects.

Methods : The Alienor study is a population-based cohort study of 963 residents of Bordeaux (France), aged 73 years or more at baseline. Of those, 829 were at risk for incident AMD and 659 (79.5%) subjects were followed up for a mean duration of 3.8 years (SD 1.1 years). AMD was graded in four exclusive stages (early AMD 1, early AMD 2, atrophic AMD and neovascular AMD) on the basis of retinal fundus photographs and spectral domain optical coherence tomography.

Results : The cumulative incidence was 26.9% (95% confidence interval (CI): 22.7-31.0) for early AMD and 6.8% (95% CI: 4.9-8.8) for advanced AMD. The incidence rates of distinct and indistinct soft drusen and pigmentary abnormalities were 19.2%, 12.1% and 22.0%, respectively. Incident advanced AMD was 0.6% in participants without any AMD at baseline, 13.8% in those with early AMD1 and 28.3% in those with early AMD 2. In multivariate analysis, progression from early to advanced AMD was significantly associated with AMD grade in the fellow eye (Hazard Ratio (HR): 13.1 to 22.3 according to stage, p<0.0001), having smoked at least 20 pack-years (HR: 2.9, 95% CI: 1.3-6.4, p=0.002) and CFH Y402H (HR: 2.6, 95 %: 1.2-5.7 for TC genotype and 1.72, 95% CI: 0.73-4.10 for CC genotype, p=0.003). Incidence of early AMD was higher in subjects with early AMD in the fellow eye (HR: 2.6, 95 % CI: 1.6-4.1 for early AMD 1 and 5.5, 95 % CI: 3.2-9.5 for early AMD 2, p<0.001). Plasma high density lipoprotein (HDL)-cholesterol was associated with increased risk for incident early AMD in age- and gender-adjusted model (HR=1.9, 95%: 1.3-2.0, p=0.003), but this association was not statistically significant in the multivariate model (HR=1.6, 95% CI: 0.9-2.6, p=0.09).

Conclusions : The incidence of AMD was similar to those observed in other populations of European descent. Risk factors appear to be different for between the incident early AMD and the progression from early to advanced AMD.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.