Abstract
Center-involved diabetic macular edema (DME) is the major cause of vision loss in the working-age population. Enduring DME might progressively injure the foveal layers with subsequent visual acuity loss. Therefore, the primary aim of DME therapy is to achieve an early, long-lasting dry macula to improve or sustain visual acuity. Current drug treatment has not achieved this aim. Diffuse DME (DDME), the most challenging DME type, is characterized by a compromised diffuse vasculature. Its pathogeneses include vitreofoveal traction and tractional epimacular membrane, as well as two newly-recognized pathogeneses: a) extrafoveal traction, the most common one, which is primarily detectable by 3D optical coherence tomography, and b) transitional-phase type, which represents the early tractional process and is detectable only ultra-structurally. Hence, all DDME eyes are apparently tractional. Consequently, treatment of naïve-treated DDME eyes by early pars plana vitrectomy has achieved long-lasting dry maculae in 92%–100% of eyes, typically in one step, and habitually associated with improved visual acuity. The surgery also naturally included the elimination of leaking microaneurysms (the "focal DME" component) when they were present. The transitional-phase type presents circumstances for attaining efficacious outcome by grid laser photocoagulation as well. Hence, DME seems to approach a curative situation. Accordingly, a revised pathogenesis-related DME classification is presented.