Extended duration strategies for the pharmacologic treatment of diabetic retinopathy: current status and future prospects

Introduction: Intraocular pharmacotherapy (vascular endothelial growth factor [VEGF] inhibitors and corticosteroids) has become first-line therapy for diabetic retinopathy (DR). A series of intraocular injections is usually required before disease modulation decreases the treatment burden in some patients, but others with chronic diabetic macular edema may require intensive longer-term therapy. Areas covered: Recent studies showing successful pharmacologic treatment of proliferative DR will probably lead to increased use of pharmacotherapy, thereby further emphasizing the need for longer duration drugs. Recently approved anti-VEGF drugs (aflibercept) and corticosteroids (dexamethasone and fluocinolone inserts) provide extended durations of action. Longer action anti-VEGF molecules, sustained release devices and pumps, and encapsulated cell technology, may further decrease treatment burden, though regulatory approval may not occur for at least 5 years. Oral medications (danazol and minocycline) and modified topical drugs (loteprednol) will require daily administration but may decrease the frequency of visits to physicians’ offices. Intravitreally administered drugs that target different biochemical pathways are being developed as monotherapy and combination therapy, and their effects on durability remains to be seen. Expert opinion: The rich development pipeline promises to provide improved therapeutic options in addition to drugs and devices with longer duration of action.