Diseases associated with the tissues in the posterior segment of the eye can be effectively treated by administering therapeutic agents transsclerally to those tissues. Compositions, devices, and methods for delivering therapeutic agents so that they cross the sclera and reach these tissues include injecting solutions or suspensions adjacent to or within the sclera and implanting solid structures containing the therapeutic agent adjacent to or within the sclera. These methods may be used for administering rapamycin or related compounds to treat choroidal neovascularization associated with age-related macular degeneration.