A Comparison between Intravitreal Bevacizumab Injection and Placement of a Dexamethasone Implant to Treat Retinal Vein Occlusion Macular Edema

Abstract

Purpose: We evaluated the macular, functional and structural features of patients with retinal vein occlusion and macular edema. We measured the best-corrected visual acuity (BCVA), central foveal thickness, and the area of the foveal avascular zone area after intravitreal bevacizumab (IVB) treatment and placement of a dexamethasone implant (IVD).Methods: We retrospectively reviewed 36 eyes of 36 patients with retinal vein occlusion and macular edema who underwent IVB treatment (20 eyes) and IVD placement (16 eyes). The parameters mentioned above were compared between the two treatment groups and the normal contralateral eyes after initial stabilization and 1 year later.Results: The BCVA was significantly higher in the IVB than the IVD group after initial stabilization and 1 year later. The intraocular pressure was lower at initial stabilization in the IVB than the IVD group, but no difference was apparent after 1 year. There was no significant between-group difference in the central foveal thickness at any time, but the IVD group required fewer injections during initial stabilization than the IVB group. In terms of the foveal avascular zone area, both the superficial and deep layers of the IVB group increased significantly during the initial stabilization period and then decreased to 1 year; no changes were seen in the IVD group.Conclusions: IVD treatment is associated with fewer injections than IVB treatment and a more stable retinal vasculature, but visual acuity may possibly decrease (because of cataract formation). Although IVB treatment improves visual acuity and reduces macular edema, this may be associated with an increased risk of macular ischemia given the need for repeated injections.