Background The purpose of this study is to evaluate the efficacy of intravitreal bevacizumab as the primary treatment of macular oedema due to retinal vein occlusions.

Methods Patients diagnosed as having central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO) with visual acuity of less than 20/40 and macular oedema with more than 300 μm central retinal thickness were recruited. Patients that had received any prior treatment were excluded. After an initial intravitreal injection of bevacizumab, re-treatment was performed if intraretinal or subretinal fluid with distortion of the foveal depression was found in optical coherence tomography.

Results 18 eyes with CRVO and 28 eyes with BRVO were included. During a 6-month period, the mean number of injections per patient was 3.7 (BRVO group) and 4.6 (CRVO group). In the BRVO group, mean baseline logMAR visual acuity was 0.80 (SD 0.38) and macular thickness was 486.9 μm (SD 138.5 μm). After 6 months, mean logMAR visual acuity improved significantly to 0.44 (SD 0.34), p<0.001. Mean macular thickness decreased significantly to 268.2 μm (SD 62.5 μm), p<0.001. In the CRVO group, mean baseline logMAR visual acuity was 1.13 (SD 0.21) and macular thickness was 536.4 μm (SD 107.1 μm). Mean final logMAR visual acuity improved significantly to 0.83 (SD 0.45), p<0.001. Mean macular thickness decreased significantly to 326.17 μm (SD 96.70 μm), p<0.001.

Conclusions Intravitreal bevacizumab seems to be an effective primary treatment option for macular oedema due to retinal occlusions. Its main drawback is that multiple injections are necessary to maintain visual and anatomic improvements.