VEGFA and macular retinal edema: To investigate whether sub-Tenon injection of triamcinolone acetonide (STTA) combined with anti-vascular endothelial growth factor (VEGF) prolongs the recurrence intervals of macular edema (ME) for chronic retinal vein occlusion (RVO) and to investigate the differences in intraocular inflammatory cytokines between good responders (GRs) and non-responders (NRs).