Diabetic macular edema (DME) is defined as the buildup of fluid within the retina in the extracellular space, specifically at the level of the macula in the inner nuclear, outer plexiform, Henle’s fiber layer, and subretinal space. Diabetes mellitus is one of the leading causes of visual impairment in industrialized countries and DME is the main reason for vision drop in diabetic patients. Several diagnostic methods are available for the characterization and staging of diabetic retinopathy (DR) and DME; the principal one for DME is optical coherence tomography (OCT), a quick and non-invasive technique that helps in decision-making for therapeutic choices based on biomarkers. Various classifications have been suggested over the years to aid in treatment management for DME. Current therapeutic options include laser photocoagulation, anti-VEGF (vascular endothelial growth factor) intravitreal injections or corticosteroids, and surgery. Recently, a surgical approach has been proposed with pars plana vitrectomy (PPV) in case vitreomacular traction is present together with DME. Refractory DME is a challenging scenario, and it may be managed by switching to a different class of intravitreal medications or with surgical intervention or micropulse laser. Future perspectives include artificial intelligence algorithms based on OCT and OCT-angiography images which may improve diagnosis and treatment of DME with better preservation of visual acuity in diabetic patients.