Chronic open-angle glaucoma is a leading cause of preventable and treatable blindness worldwide. However, if left untreated is to progress inexorably to irreversible blindness. Early treatment of elevated intra-ocular pressure will maintain visual function. This is a multinational study involving Australia, Spain and Canada. The aim of the project is to describe the demographic and ocular and non-ocular comorbidities in people with OAG; evaluate treatment patterns of glaucoma topical medications and procedures and estimate the associated direct healthcare resource utilization for OAG treatments.