Intracameral sustained release bimatoprost implants (Durysta)

Sustained release drug delivery has the potential to change glaucoma care by decreasing the challenge of medication adherence. Many approaches are in development, but this review focuses on Durysta (Allergan plc, Dublin, Ireland), the only FDA-approved sustained release intracameral treatment available at this time.

Durysta is a bimatoprost sustained release (BimSR) intracameral implant. Clinical trials have demonstrated that BimSR implants can provide comparable levels of intraocular pressure (IOP) control as topical eyedrops. BimSR has advantages such as decreasing concerns regarding drop adherence, reducing ocular surface and periocular side effects from topical drops, and decreased daily treatment burden for patients. In addition, studies have shown continued IOP lowering in some eyes during extended follow-up periods when all of the BimSR medication has already been delivered. Hypothesized mechanisms to explain this finding include increased matrix metalloproteinase expression that causes extracellular matrix reorganization to permit greater aqueous outflow, as well as decreased episcleral venous pressure. The major safety concern at this time for Durysta and future intracameral implants is corneal endothelial cell loss, which was worse with repeat BimSR administration compared to single dosing. Several studies are underway to investigate mechanisms of action and to better understand safe and effective dosing of medications in this class.