Prevalence of age-related macular degeneration associated genetic risk factors and 4-year progression data in the Irish population

Abstract

Background/aims: Age-related macular degeneration (AMD) is estimated to affect 196 million people >50 years old globally. Prevalence of AMD-associated genetic risk factors and rate of disease progression are unknown in Ireland.

Methods: Prevalence of AMD-associated genetic risk variants, complement factor H (CFH) rs1061170, age-related maculopathy susceptibility 2 (ARMS2) rs10490924, component 3 (C3) rs2230199, complement factor B (CFB) rs641153 and superkiller viralicidic activity 2-like (SKIV2L) rs429608 and 4-year progression data in a population-representative cohort (The Irish Longitudinal study on Ageing (TILDA)) were assessed. 4473 participants ≥50 years were assessed. 4173 had no disease n=1843; 44% male and n=2330; 56% female, mean age 60±9.0, 300 had AMD n=136; 45% male and n=164; 55% female, mean age 64±9.0. A 4-year follow-up was undertaken with 66% of AMD cases attending. Progression and regression from early to late AMD were measured. Genetic association as indicators of disease and as predictors of progression were assessed by multinomial logistic regression.

Results: Older age and the presence of CFH and ARMS2 risk alleles are two main risk factors associated with the prevalence of AMD in the TILDA cohort. 23% progressed to a higher grade of AMD. Carriers of CFH risk allele showed a strong association for disease progression. Heterozygosity for ARMS2 risk allele predicted progression to late AMD. 75% of those who progressed from early to late disease had soft drusen and hyperpigmentation at baseline.

Conclusions: The prevalence of risk-associated genes and 4-year progression rates of AMD in this Ireland cohort are comparable with other Caucasian populations. CFH Y402H is associated with disease progression, with soft drusen and hyperpigmentation as high-risk features.

Keywords: degeneration; epidemiology; genetics; macula; public health.