International Consensus and Guidelines on Diagnosing and Managing Pachydrusen from APVRS, AEEC, APOIS, AAPPO, and ARI

Purpose: To establish evidence-based consensus statements on pachydrusen, a distinct drusen subtype associated with increased choroidal thickness, addressing current knowledge gaps in diagnosis, clinical significance, and management. Methods: An international expert panel systematically reviewed existing literature on pachydrusen characteristics, prevalence, and clinical associations. Consensus statements were developed through structured analysis of morphologic features, diagnostic criteria, and clinical outcomes across diverse populations. Results: Pachydrusen are morphologically distinct from soft drusen and subretinal drusenoid deposits, characterized by irregular, multilobulated yellow-white deposits ≥125 μm with sharp borders. The genetic observations suggest that pachydrusen represent a distinct subtype within the age-related macular degeneration (AMD) spectrum. Prevalence varies markedly by ethnicity. Pachydrusen are frequently observed in eyes with polypoidal choroidal vasculopathy and type 1 macular neovascularization when exudation is present, although their presence is not consistently associated with an increased risk of exudative change and they rarely progress to geographic atrophy. They are associated with increased choroidal thickness and choroidal vascular alterations. Although multimodal imaging may provide additional insights into associated choroidal features, standardized criteria for color fundus photography–based identification are essential. The clinical significance regarding progression risk to late AMD needs further elucidation. Conclusions: Pachydrusen are a distinct drusen subtype associated with generalized or localized choroidal thickening, but not necessarily with diffuse thickening. Recognition of pachydrusen highlights the importance of considering genetic background, ethnicity, and choroidal characteristics in AMD research and management.