Age-related macular degeneration (AMD) is the leading cause of blindness in aging adults and affects millions of patients in the U.S. and even more worldwide. Existing treatments of the most devastating neovascular form of AMD involve monthly injections into the eye(s) of patients, who typically are elderly. These injections are costly and burdensome, requiring periodic intraocular injections for drug delivery. Radiation has been used to treat AMD: 6 MV external-beam radiation irradiation, proton therapy, and most recently stereotactic x-rays and beta applicators. Prior attempts have suffered from technological issues where radiation source placement was imprecise, radiation had to traverse the eye to target the macula, or dose delivery was impeded by patient-specific anatomic variation (especially at small distances). The iWand® brachytherapy device (LV Liberty Vision, Portsmouth, NH) has been developed to address these design and implementation issues. The iWand® provides light-guided radiation placement adjacent to the targeted macular while providing a conformal and precise dose distribution for treatment of AMD. The source uses Y-90 (a short-lived beta-emitter) and rationale for this choice is examined in the current study.