This article presents the protocol of a prospective, observational, nonrandomized study of the use of mirabegron in patients with age-related macular degeneration (dry AMD) and overactive bladder (OAB). Mirabegron is a beta 3 adrenoceptor agonist, licensed for the treatment of OAB, with the potential to reduce angiogenic proliferation in the retina, which could prevent the transition from dry to wet (neovascular) AMD. Anti-vascular endothelial growth factor drugs have revolutionized the treatment of wet AMD, but prevention of conversion from the dry form provides a better long-term visual prognosis. OAB and AMD are common in older adults and share risk factors, suggesting the need for joint treatment. Mirabegron has a safe eye profile as it does not affect macular and choriocapillary parameters in patients with OAB. The aim of the study is to evaluate the effect of mirabegron on slowing the progression of AMD from dry to neovascular form in patients with both diseases. The study is registered under the identifier NCT07305298.