The African Descent and Glaucoma Evaluation Study (ADAGES) III: Contribution of Genotype to Glaucoma Phenotype in African Americans. Study Design and Baseline Data

PURPOSE: To describe the study protocol and baseline characteristics of the “African Descent and Glaucoma Evaluation Study (ADAGES) III: Contribution of Genotype to Glaucoma phenotype in African Americans”. DESIGN: Cross-sectional, case-control study PARTICIPANTS: There were 3266 glaucoma patients and controls without glaucoma of African or European descent recruited from five study centers in different regions of the United States. METHODS: Individuals of African descent (AD) and European descent (ED) with primary open angle glaucoma (POAG) and control subjects completed a detailed demographic and medical history interview. Standardized height, weight and blood pressure measurements were obtained. Saliva and blood samples to provide serum, plasma, DNA and RNA were collected for standardized processing. Visual fields, stereoscopic disc photographs, and details of the ophthalmic examination were obtained and transferred to the University of California-San Diego Data Coordinating Center for standardized processing and quality review. MAIN OUTCOME MEASURES: Participant gender, age, race, body mass index, blood pressure, history of smoking and alcohol use in POAG patients and controls are described. Ophthalmic measures included intraocular pressure, visual field mean deviation, central corneal thickness, glaucoma medication use or past glaucoma surgery. Ocular conditions including diabetic retinopathy, age-related macular degeneration and past cataract surgery were recorded. RESULTS: The 3266 ADAGES III study participants in this report include 2146 AD POAG patients, 695 ED POAG patients, 198 AD controls and 227 ED controls. AD POAG patients and controls were significantly younger (both 67.4 years) than ED POAG patients and controls (73.4 and 70.2 years, respectively). After adjusting for age, AD POAG patients had different phenotypic characteristics compared to ED POAG patients, including higher intraocular pressure, worse visual acuity and visual field mean deviation, and thinner corneas (all p