Prognostic factors for visual outcome after intravitreal bevacizumab for macular edema due to branch retinal vein occlusion

Purpose To evaluate the prognostic factors for visual outcome after intravitreal bevacizumab injection to treat macular edema due to branch retinal vein occlusion (BRVO). Methods Fifty eyes of 50 consecutive patients treated with intravitreal bevacizumab for macular edema due to BRVO with minimum follow-up of 3 months were retrospectively reviewed. Patients were categorized into two groups according to the final visual acuity. Group 1 consisted of eyes with 5 or more ETDRS letters gain, and group 2 consisted of eyes with less than 5 letters improvement or which had worsened at last follow-up visit. Comparative clinical and fluorescein angiographic characteristics were analyzed between the two groups. Results Of 50 eyes, 28 (56%) had improved vision after intravitreal bevacizumab injections and were categorized as group 1; 22 eyes (44%) were categorized as group 2. The number of early VA gainers, who showed visual improvement at 1 month after bevacizumab injection, was significantly higher in group 1 (P < 0.001, chi-square test). The early gainers tend to maintain significantly better visual outcome until last follow-up. The number of eyes with angiographically documented macular ischemia was significantly higher in group 2 (P<0.001). In group 2, the decrease in central macular thickness was not accompanied by visual acuity improvement. Conclusion Preoperative presence of macular ischemia can be useful in predicting the outcome of visual acuity after intravitreal bevacizumab for macular edema due to BRVO. The early gainers who favorably responded to the initial intravitreal bevacizumab injection are most likely to benefit from the bevacizumab treatment.