Heritability and Risk Factors of Incident Small and Large Drusen in the Copenhagen Twin Cohort Eye Study: A 20-Year Follow-Up

Abstract Introduction: The transition from a normal fundus to one with early drusen (≥20 small hard drusen) to age-related macular degeneration (AMD) in the form of drusen ≥63 μm in diameter is of interest, because small hard drusen may be precursors of large drusen. Study of AMD precursor lesions may provide valuable insight into factors that initiate AMD. Here, the progression of drusen was studied over an interval of 20 years in a population-based twin cohort. Methods: Single-center, 20-year follow-up of 138 twins include biometry, fundus optical coherence tomography, and fundus photography. Macular characteristics were hierarchically classified as (per eye) (1)