Abstract: The first-line clinical treatment for diabetic macular edema (DME) is intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF). Treat and extend (T&E) is an active treatment regimen in which patients are treated until the lesion is stable and the interval of treatment can be extended or shortened during the follow-up period depending on whether the disease is stable. This regimen is being progressively used in the treatment of patients with DME. Compared with commonly used treatment regimens, the T&E regimen reduces the risk of fewer fixed injections per month and overtreatment while avoiding the possibility of undertreatment every two months. Follow-up intervals can be adjusted according to best-corrected visual acuity (BCVA) or central retinal thickness (CRT), and regular treatment can improve vision and anatomy as compared to on-demand treatment regimens. However, there is no unified standard for the design of T&E protocol in the current study, and more clinical studies are needed to further standardize it. (Int Rev Ophthalmol, 2021, 45: 477-482)

Key words: diabetic macular edema, treat and extend protocol, anti-vascular endothelial growth factor