Clinical and genetic characteristics of pachydrusen in patients with exudative age-related macular degeneration

We investigated the clinical and genetic characteristics of patients with unilateral exudative age-related macular degeneration (AMD), including typical AMD, polypoidal choroidal vasculopathy, and retinal angiomatous proliferation, in whom pachydrusen was seen. Patients with unilateral exudative AMD with at least a 12-month follow-up period were included. According to the fellow eye condition, 327 consecutive patients were classified into 4 groups: Group 0: no drusen (42.8%), Group 1: pachydrusen (12.2%), Group 2: soft drusen (30.3%), Group 3: pseudodrusen with or without soft drusen (14.7%). Development of exudative AMD in the fellow eye was retrospectively studied for a 60-month period and this inter-group comparisons were performed. Genotyping was performed for ARMS2 A69S and CFH I62V. The thickness of the choroid in the fellow eyes increased significantly in Group 1 than in other groups (all P < 1.0 × 10−7). The development of exudative AMD in the fellow eye was significantly less frequent in Group 1 than in Groups 2 or 3 (P = 0.022 and 0.0015, respectively). Risk allele frequency of ARMS2 A69S was significantly lower in Group 1 than in Group 2 and 3 (all P < 1.0 × 10−4). Patients with pachydrusen have genetic and clinical characteristics distinct from those of soft drusen and pseudodrusen.