AAVCAGsCD59, an ocular gene therapy product that is injected in to the eye in the physician's office, causes normal retinal cells to increase the expression of a soluble form of CD59 (sCD59). This soluble recombinant version of the naturally occurring CD59 is designed and intended to protect retinal cells that are responsible for central vision by inhibiting the formation of the membrane attack complex (MAC), the terminal step of complement-mediated cell lysis. In gene therapy the cells of the retina are potentially permanently altered to make sCD59 for the life of the patient. With gene therapy only one injection is needed for the drug to be effective for the patient's entire life. This study will evaluate the safety after a single injection of AAVCAGsCD59 administered in an office setting for patients whose enrolled eye has advanced dry AMD with geographic atrophy. The initial study is 26 weeks followed by an additional 18-month safety evaluation.