Design and Baseline Characteristics of the Korean Age-Related Maculopathy Study (KARMS): A Nationwide Multicenter Prospective Observational Study

PurposeTo describe the design and baseline characteristics of the Korean Age-Related Maculopathy Study, a nationwide prospective cohort investigating age-related macular degeneration (AMD) in Koreans.DesignA 5-year prospective observational study conducted across 33 tertiary hospitals and ophthalmology clinics in Korea.ParticipantsA total of 1159 Korean participants diagnosed with nonexudative or exudative AMD.MethodsParticipants aged 50 to 80 years were assigned to the A Study for Intermediate AMD Natural Outcome (ASIANO) arm (nonexudative) or Korean Exudative AMD Treatment Study (KEATS) arm (newly diagnosed exudative AMD). A Study for Intermediate AMD Natural Outcome arm 1 included bilateral intermediate AMD with classic drusen (soft, reticular pseudodrusen, cuticular, or calcified drusen) without advanced AMD. A Study for Intermediate AMD Natural Outcome arm 2 included pachychoroid spectrum disease with unilateral or bilateral findings such as pachydrusen with retinal pigment epithelium undulation, focal attenuation of inner choroidal vessel, and dilated outer choroidal vessels or pigmentary abnormalities corresponding retinal pigment epithelium elevation or disruption in OCT, without significant classic drusen. The KEATS arm comprised active exudative AMD, including typical exudative macular neovascularization, polypoidal choroidal vasculopathy, and retinal angiomatous proliferation. All underwent standardized multimodal imaging at baseline and are followed annually.Main Outcome MeasuresBaseline demographic, behavioral, and ocular characteristics across drusen-driven, pachychoroid-driven, and exudative AMD phenotypes.ResultsOf the 1409 individuals screened, 1159 were enrolled (ASIANO 1: 551; ASIANO 2: 317; KEATS: 291). A Study for Intermediate AMD Natural Outcome arm 1 participants were older, predominantly female, and universally bilateral; arm 2 participants were younger, more often male, and frequently unilateral. Korean Exudative AMD Treatment Study showed a high proportion of patients with polypodal choroidal vasculopathy (39.5%, patient-based) and male predominance. Behavioral profiles also differed: the KEATS arm had lower eye-supplement use, higher smoking exposure, and less frequent sunglasses/sun-visor use. Exploratory follow-up analyses suggested differing rates of exudative conversion between ASIANO arm 1 and arm 2.ConclusionsKorean Age-Related Maculopathy Study is the first large-scale, nationally representative prospective cohort in Koreans, distinguishing drusen-driven and pachychoroid-driven maculopathy phenotypes and detailing exudative subtypes. These baseline data provide a foundation for future phenotype-specific progression analyses and management strategies in Asian populations.Financial Disclosure(s)Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.