Described are implantable therapeutic devices, systems and methods to treat a patient. The device includes a hollow refillable housing for implantation within the posterior segment of an eye through a penetration in the sclera including a proximal retention structure protruding outward from a proximal end region of the housing, an access portion opening, and a penetrable barrier positioned at least in part within the access portion opening, the penetrable barrier configured to be repeatedly penetrated. A rigid porous structure is positioned within a region of the housing away from the access portion opening into a reservoir chamber extends along an axis between the penetrable barrier and the porous structure includes a volume sized to deliver therapeutic amounts of a therapeutic agent to the eye for an extended period of time. A cover is coupled to at least an upper surface of the proximal retention structure.
