Drug delivery to the back of the eye currently relies largely on localized drug
delivery systems. These systems provide high drug concentrations at the target sites and
low concentrations in the systemic circulation, thereby improving the risk: benefit ratio
of the therapeutic agent. Since localized drug delivery requires either a surgical
procedure or an injection in or around the eye, drug delivery systems developed for the
back of the eye are either self-sustaining or slow release systems. In this chapter,
various drug delivery systems including non-degradable implants, biodegradable
implants, encapsulated cell technology based implants, microparticles, nanoparticles,
liposomes, micelles and hydrogels suitable for localized drug delivery to the back of the
eye are discussed. Further, iontophoretic approaches are also briefly addressed.
Keywords: Drug delivery systems, Implants, Microparticles, Nanoparticles,
Liposomes, Micelles, Hydrogels, Iontophoresis, Posterior eye.
