Lacrimal implants and related methods providing secure retention within the lacrimal punctum of an eye are described. The lacrimal implants can comprise a implant body configured for at least partial insertion through the lacrimal punctum and into a lacrimal canaliculus. The implant body can include a deformable retention structure that can be configured to substantially encapsulate an expandable retention element. In some examples, the expandable retention element can include a fluid absorbing material, which can be exposed to fluid such as via a fluid permeable retainer or a fluid permeable aperture. As the fluid absorbing material retains fluid (i.e., upon acceptance of fluid into the retention structure), its size increases and its shape can change to urge one or more portions of the retention structure outward, such as against a wall of the lacrimal canaliculus, thereby securely retaining the lacrimal implant within the punctum.
