Bevacizumab versus bevacizumab and macular grid photocoagulation for macular edema in eyes with non-ischemic branch retinal vein occlusion: results from a prospective randomized study

Abstract

Background: The objective of the study was the investigation of the effects of intravitreal bevacizumab (BEV) with or without additional macular grid laser photocoagulation (GRID) for macular edema (ME) secondary to branch retinal vein occlusion (BRVO).

Methods: Prospective, randomized, monocentric study. Thirty-two patients were included. Initially, all eyes in both groups received three monthly injections of BEV, followed by additional injections if re-treatment criteria were met. In the BEV + GRID group, photocoagulation was performed 2 weeks after the first BEV injection and laser re-treatment was allowed. The follow-up was 38 weeks. Main outcome measures were best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Changes of foveal avascular zone (FAZ) and of retinal ischemia, as well as the number of injections were also evaluated.

Results: Sixteen eyes were randomized into each group. At baseline, BCVA was similar in both groups (BEV + GRID: 20/71; BEV: 20/60; P = 0.51). At 38 weeks, BCVA significantly improved in the two groups (BEV + GRID gain of 9 ± 11.2 letters and 16.25 ± 10.08 letters in the BEV) with no difference between them (P < 0.06). With regard to anatomical findings, initial CRT in BEV + GRID was 496.2 μm ± 138.4 μm and 538.9 μm ± 156.9 μm in BEV (P < 0.1697). At 38 weeks, CRT decreased in both groups significantly, 98.2 μm in the BEV + GRID (P = 0.02) and 141.7 μm in the BEV group (P = 0.01), with no significant difference between groups (P < 0.17). The area of FAZ a significantly increased in both groups (41% (P = 0.04) in BEV + GRID; 35% (P = 0.03) in BEV) during the study and the grade of peripheral ischemia remained unchanged. The mean number of injections was 3.8 (range 3-6) with no significant difference between groups.

Conclusions: Our data demonstrate a beneficial effect of bevacizumab in ME in eyes with BRVO. A loading phase of three injections led to a significant improvement in vision in both groups, which persisted at week 38. Additional grid laser photocoagulation exhibited no beneficial functional or anatomical effect during the study, nor did it reduce the number of injections. The FAZ area increased significantly in both groups, but overall retinal ischemia did not. Further studies investigating more numerous eyes and longer follow-up are needed to confirm these data.

Keywords: Anti-VEGF; Bevacizumab; Branch retinal vein occlusion; Grid laser photocoagulation; Macular edema.