Posterior segment drug delivery

An implantable therapeutic device to treat an eye of a patient having a posterior chamber and a sclera, the therapeutic device comprising:

• a rigid, hollow, refillable body for implantation within the posterior chamber of the eye through a penetration in the sclera, the body formed of a substantially rigid, impermeable wall of biocompatible material, the body having a proximal cap portion adapted to be positioned outside the sclera, an intermediate neck portion, and a distal reservoir portion adapted to reside in the posterior chamber such that the sclera is positioned about the neck portion when the device is positioned in the eye, wherein the neck portion has a smaller transverse outer dimension than at least one transverse outer dimension of the cap portion and at least one transverse outer dimension of the reservoir portion;
• the cap portion adapted to receive an injection of a therapeutic agent into the reservoir and to remain external to the posterior chamber;
• and
• a rigid porous structure having a plurality of interconnecting, irregularly shaped channels, said rigid porous structure coupled to a discrete, distal portion of the reservoir and tuned to release therapeutic amounts of a therapeutic agent from the reservoir through said plurality of channels and into said posterior chamber for an extended time, wherein the therapeutic device has a substantially fixed volume during implantation and use.