Intravitreal dexamethasone implant (ozurdex) in the management of treatment naive diabetic macular edema

Patients with diabetes develop endothelial dysfunction which causes leakage of retinal microvasculature. The elevated pro- inflammatory cytokines and reduced anti inflammatory cytokines predispose to extravasation of fluid from the retinal vessels leading to diabetic macular edema. Initially, laser photo-coagulation was the mainstay of treatment, but it has limited effect in restoring vision. Anti-VEGF, although found effective, has the disadvantage of requiring frequent injection and follow up. Intra-vitreal corticosteroid implant overcomes the disadvantage of frequent dosing and the associated frequent injection related complications .Dexamethasone is a corticosteroid and has actions at the level of nucleus and gene expression. Corticosteroids prevents new vessel formation by suppressing angiogenic factors, including VEGF. It also increases the level of anti-inflammatory proteins. It maintains the integrity of tight junctions of the blood retinal barrier and also promotes clearance of retinal fluids. Ozurdex, containing 0.7mg dexamethasone, is biodegradable drug approved for treating diabetic macular edema and releases dexamethasone into the vitreous over a period of ≤6 month. This thesis evaluates the efficacy of dexamethasone intra-vitreal implant in the management of treatment naive diabetic macular edema.