Clinical use of Dexamethasone Implants in Resistant Macular Edema Secondary to Branch Retinal Vascular Occlusion compared with Intravitreal Anti-Vascular Endothelial Growth Factor

INTRODUCTION: Branch retinal vein occlusion (BRVO) is the second most common type of retinal vascular disorder. Both inflammation and increased vascular endothelial growth factor levels play important roles in the pathogenesis of macular edema (ME) secondary to BRVO. In this study we aimed to compare the efficacy of 0.7mg intravitreal dexamathasone implants with continued anti-VEGF treatment in patients with ME secondary to BRVO who were poor-responders to at least 6 previous anti-VEGF injections.
METHODS: Patients exhibiting insufficient responses to at least six ranibizumab who were subsequently changed to dexamethasone implant were included group 1. Patients who had risks for cataract, glaucoma continued on the same drug as in group 2. BCVA and central macular thickness (CMT) changes at month 2, 4, and 6 were measured.
RESULTS: Ninety eyes were evaluated. In group 1, the mean baseline BCVA was 0.71±0.75 logMAR improved to 0.53±0.62 logMAR at month 2 (p<.001), 0.67±0.72 logMAR at month 4 (p=0.325), and 1.03±0.83 logMAR at month 6 (p=.001). In group 2, the mean baseline BCVA was 0.73±0.83 logMAR and improved to 0.68±0.83 logMAR at month 2 (p=0.12), 0.698±0.81 logMAR at month 4 (p=0.270), and 0.76±0.80 at month 6 (p=0.546).
The baseline CMT in groups 1 and 2 were 588±176 and 545±165, respectively (p=0.248). The mean CMT of group 1 changed from baseline (588±176 μm) to 308±132 μm at month 2 (p<.001), 450±195 μm at month 4 (p<.001), and 510±190 μm at month 6 (p<.001). The mean CMT of group 2 changed from baseline (545±165 μm) to 486±162 μm at month 2(p<.001), 516±168 μm at month 4 (p<.001), and 528±171 μm at month 6 (p=0.037).

DISCUSSION AND CONCLUSION: Dexamethasone implants were more effective treatment for patients with BRVO-related resistant macular oedema than ranibizumab at month 2. However, this positive effect seems to decline rapidly in the long-term.