Sustained drug delivery in glaucoma.

PURPOSE OF REVIEW: This article reviews recently published studies and important clinical trials of novel drug delivery systems for glaucoma and evaluates the potential of these systems to provide sustained therapeutic benefits.

RECENT FINDINGS: The efficacy of topical medications to lower intraocular pressure (IOP) is limited by poor patient adherence, low bioavailability of drug and the potential for local and systemic side effects. Recent studies highlight the potential for sustained drug delivery through innovative delivery platforms. Nanoparticle-based formulations, drug-eluting contact lenses, punctum inserts and bioadhesive matrices placed in the conjunctival sac can enhance drug delivery by increasing precorneal residence time, enhancing corneal permeation and lowering the systemic absorption of drug. Periocular injections and surgically implanted drug reservoirs could offer even greater duration of drug delivery, particularly when the drug is packaged within stable vehicles.

SUMMARY: Novel platforms for providing sustained drug delivery in glaucoma continue to evolve. The ability to incorporate effective commercially available drugs into more stable compounds is an important element. Although more research is needed to establish their clinical efficacy, novel delivery systems will allow for more targeted medical therapy and for the opportunity to further explore neuroprotective and gene-based therapies.