macular edema therapy using dexamethasone nanoparticle suspension PURPOSE To determine the effectiveness and safety of a new topical nanoparticle dexamethasone ophthalmic suspension OCS-01 (Oculis SA, Lausanne, Switzerland) in the treatment of diabetic macular edema (DME). STUDY BACKGROUND Diabetic macular edema (DME) is the main cause of visual impairment in patients with diabetic retinopathy (DR).