The primary goal of this project is to identify major genetic factors that are responsible for POAG in persons of African ancestry. Primary open angle glaucoma (POAG) is the most common type of glaucoma in the world, and is the cause of glaucoma in over 90% of those living with glaucoma in Sub Saharan Africa (SSA). POAG has a complex genetic etiology, and moreover manifests as a health disparity that disproportionately affects individuals of African descent. In major population-based studies in Ghana, more than 6% of those over the age of 40 were affected with POAG, and more than 40% of patients diagnosed with POAG are blind in one or both eyes. This places a huge financial and societal burden on Africans. Populations of the African diaspora are also disproportionately affected. In African Americans, the prevalence of POAG is 4-5% over the age of 40, which is over four fold higher than in age-matched Caucasians. The risk of blindness from POAG is 10 times greater for African Americans than for Caucasians, making it the most common cause of permanent blindness in African Americans. We will collect DNA from approximately 6,000 individuals with POAG and 6,000 matched controls from multiple countries in Africa. These samples will be genotyped on the Illumina H3Africa custom chip. Data will be imputed and GWAS will be performed. We will also use this data to assist in the linkage analysis of multiplex families with early-onset glaucoma, and to conduct QTL analyses to identify any genomic loci that are associated with treatment outcome in the Sub Saharan Africa Glaucoma Laser Trial.