Abstract
Purpose :
The transition from normality to early drusen (≥ 20 small hard drusen or drusen ≥ 63 µm in diameter) has received little attention. As hypothesized by some researchers, small hard drusen precede the development of large drusen. Consequently, they should share similar genetic and environmental associations. The purpose was to research, by examining lesion-by-lesion, the genetic and environmental factors associated with the 20-year incidence of early drusen and whether small hard drusen are associated with large drusen.
Methods :
A single-center, 20-year follow-up cohort study comprising 138 twins at the Department of Ophthalmology, Rigshospitalet. Examinations included biometry, fundus optical coherence tomography, and fundus photography. Each macula was classified, at baseline and follow-up, as having 1) < 20 small hard drusen, 2) ≥ 20 small hard drusen, 3) drusen ≥ 63 µm, and 4) ≥ 20 small hard drusen combined with drusen ≥ 63 µm.
Results :
The median age was 59 (range 41 - 66) years. Of 25 (18.1%) incident cases, 7 had developed ≥ 20 small hard drusen, 18 had developed drusen ≥ 63 µm, whereas none had developed the combination of the two traits. Smoking was associated with incident ≥ 20 small hard drusen (p = 0.04) and with incident drusen ≥ 63 µm (p = 0.003). At baseline, having≥ 20 small hard drusen was associated with incident drusen ≥ 63 µm at follow-up (p = 0.02). Development of drusen ≥ 63 µm was attributable to 49% genetic effects and 51% environmental effects.
Conclusions :
Incident cases with ≥ 20 small hard drusen or drusen ≥ 63 µm were strongly associated with smoking and genetic predisposition. Having ≥ 20 small hard drusen at baseline was associated with having developed incident drusen ≥ 63 µm after 20 years.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.