VEGFA and macular retinal edema: VEGF is closely related to the occurrence and development of DR and DME.11-14 VEGF expression in the vitreous cavity of DME patients increases significantly, further damaging the blood-retinal barrier and increasing the retinal permeability, resulting in DME.11,13 Anti-VEGF drugs can penetrate the choroid, thus counteracting VEGF’s effect in the large choroidal vessels and choroidal capillaries and further improving patients’ visual acuity by reducing angiogenesis.11-14 Clinically, macular oedema treatment involving the fovea is difficult.