Asian age-related macular degeneration phenotyping study: rationale, design and protocol of a prospective cohort study

Background: Current knowledge of the phenotypic characteristics (e.g. clinical features, risk factors, natural history and treatment response) of age-related macular degeneration (AMD) in Asians remains limited. This report summarizes the rationale and study design of a prospective observational study of Asian neovascular AMD, including polypoidal choroidovasculopathy variant. Design: The Asian AMD phenotyping study is a prospective, observational clinical study of Asian patients with neovascular AMD or polypoidal choroidovasculopathy in three tertiary eye centres in Singapore. Participants: The study aims to recruit 500 consecutive patients from the retinal clinics of three tertiary eye centres in Singapore. Methods: Standardized examination procedures include interviews, a comprehensive eye examination, digital photography of the retina, fundus fluorescein and indocyanine green angiography and spectral domain optical coherence tomography using a standardized protocol. Blood samples were collected for biochemical analyses and stored for genetic and proteomic studies. Main Outcome Measures: The aim of the study was to build a comprehensive database of clinical, angiographic, functional and natural history data of Asian AMD over a 12-month follow-up period. Results: This article discusses the methodology and design of this prospective multi-centred study. Conclusion: This study will provide in-depth longitudinal data of the evolution of clinical features, risk factors, natural history and treatment pattern and response of Asian AMD and polypoidal choroidovasculopathy, allowing unique insights into pathogenesis and the design of new treatment strategies.