Bevacizumab Versus DEX Implant Followed by Bevacizumab in ME Secondary to BRVO

Retinal vein occlusion is the second most common retinal vessel disease following diabetic retinopathy. It is divided into central retinal vein occlusion and retinal vein occlusion. Visual disturbance resulting from retinal vein occlusion is mainly caused by macular edema, and one of the main mechanisms of macular edema is increased vascular endothelial growth factor. Increased vascular endothelial growth factor is known to cause macular edema by breaking blood retinal barrier and causing leakage. For this reason, intravitreal injection of anti - vascular endothelial growth factors is currently used to treat macular edema due to retinal vein occlusion. Corticosteroid is a different mechanism from anti - vascular endothelial growth factor, and it is the main mechanism to suppress macular edema, to suppress the expression of inflammatory mediators, to block the inflammatory reaction pathway, and to lower the vascular endothelial growth factor concentration in the vitreous body. The dexamethasone implant in the vitreous cavity showed the maximum visual improvement effect during 60 day after one injection, and the effect continued until about 90 days after the injection. The same effect was obtained with a fewer injection times compared to the injection of the anti-vascular endothelial growth factor and a variety of inflammatory. It is also effective in patients who do not respond to anti-vascular endothelial growth factors by effectively inhibiting cytokines and growth factors. However, steroids elevated intraocular pressure, it is limited in repeated use.

Intravitreal dexamethasone implantation and anti-vascular endothelial growth factor showed similar early vision improvement. The differences in these anatomical changes may be different in long-term visual prognosis. After 3 doses of loading dose of anti-vascular endothelial growth factor, each group was injected with anti-vascular endothelial growth factor (VEGF) at each recurrence of macular edema and injected with anti-vascular endothelial factor at each macular reattachment after dexamethasone injection. The results of this study are as follows.