PREDICTORS OF REFRACTORY MACULAR EDEMA AFTER BRANCH RETINAL VEIN OCCLUSION FOLLOWING INTRAVITREAL BEVACIZUMAB.

Abstract

To evaluate the predictors of refractory macular edema (ME) that develops despite multiple bevacizumab injections in patients with branch retinal vein occlusion (BRVO). A total of 107 patients who followed at least 2 years were assigned to 2 groups: a refractory group (n = 56) and a responsive group (n = 51). Baseline characteristics, treatment response at 3 months, and fluorescein angiographic findings at 6 months were compared. Then we tried to identify factors associated with refractory ME development. Compared to the responsive group, the refractory group had older age, longer pre-treatment duration, and shorter occlusion distance from disk. At 3 months, the refractory group exhibited lower visual acuity, thicker central retinal thickness (CRT), and larger proportion of external limiting membrane (ELM) and outer plexiform layer disruption. After 6 months, proportion of unresolved vein occlusion, macular ischemia, number of microaneurysms, and non-perfusion areas were higher in the refractory group. Refractory ME was associated with pre-treatment duration ≥3 months, short occlusion distance from disk, thick CRT and ELM disruption at 3 months, and unresolved vein occlusion at 6 months. If BRVO-ME patients exhibit the above-mentioned characteristics, they may have refractory ME, which should inform treatment decisions.