A drug delivery ocular implant (53), comprising an outer shell (54) shaped to define an interior space, one closed distal end, and one open proximal end； a drug (62) contained within the interior space (58)； a cap (54a) dimensioned to fit within or over the one open end and having at least one region (56) of drug release； a permeable or semi-permeable material covering the at least one region of drug release, the permeable or semi-permeable material being permeable or semi-permeable to the drug； and a retention protrusion (359) on the closed distal end.
