A therapeutic device to deliver a therapeutic agent to an eye having a sclera, a conjunctiva over the sclera and a vitreous humor, the device comprising: a container configured to hold the therapeutic agent, wherein the container comprises: a refillable reservoir configured to have a volume sized to contain a liquid formulation of the therapeutic agent; a barrier defining a size of the refillable reservoir and formed of a material to inhibit release of the therapeutic agent from the container; and a rigid porous structure (150, 158), wherein the reservoir and the rigid porous structure (150, 158) are tuned to release therapeutic amounts of the therapeutic agent for an extended time into the vitreous humor; an injection port extending to the container and having a channel which is configured to extend through the sclera, when the container is implanted at least partially within the vitreous humor, and configured to receive an injection of therapeutic agent to refill the container; and a retention structure coupled to the container configured to couple to the sclera and retain the container at least partially within the eye, the retention structure comprising a flange extending outward for placement, in use, between the sclera and the conjunctiva, the flange being coupled to the container by a narrow portion, wherein the narrow portion is sized smaller than the flange and has an elongate cross-section sized to fit within an elongate incision in the sclera, wherein the volume of the reservoir remains substantially fixed and the rigid porous structure (150, 158) remains rigid when the therapeutic agent is injected into the reservoir with at least some pressure. a container configured to hold the therapeutic agent, wherein the container comprises: a refillable reservoir configured to have a volume sized to contain a liquid formulation of the therapeutic agent; a barrier defining a size of the refillable reservoir and formed of a material to inhibit release of the therapeutic agent from the container; and a rigid porous structure (150, 158), wherein the reservoir and the rigid porous structure (150, 158) are tuned to release therapeutic amounts of the therapeutic agent for an extended time into the vitreous humor; a refillable reservoir configured to have a volume sized to contain a liquid formulation of the therapeutic agent; a barrier defining a size of the refillable reservoir and formed of a material to inhibit release of the therapeutic agent from the container; and a rigid porous structure (150, 158), wherein the reservoir and the rigid porous structure (150, 158) are tuned to release therapeutic amounts of the therapeutic agent for an extended time into the vitreous humor; an injection port extending to the container and having a channel which is configured to extend through the sclera, when the container is implanted at least partially within the vitreous humor, and configured to receive an injection of therapeutic agent to refill the container; and a retention structure coupled to the container configured to couple to the sclera and retain the container at least partially within the eye, the retention structure comprising a flange extending outward for placement, in use, between the sclera and the conjunctiva, the flange being coupled to the container by a narrow portion, wherein the narrow portion is sized smaller than the flange and has an elongate cross-section sized to fit within an elongate incision in the sclera, wherein the volume of the reservoir remains substantially fixed and the rigid porous structure (150, 158) remains rigid when the therapeutic agent is injected into the reservoir with at least some pressure.