The use of anti-vascular endothelial growth factor in the treatment of retinal vein occlusion: a paradigm shift in management

Aims: This study aimed, firstly, to investigate the efficacy of intravitreal anti-vascular endothelial growth factor injection on macular edema and other ocular complications of retinal vein occlusion in Hong Kong. Secondly, to compare the efficacy of bevacizumab and ranibizumab in the treatment of retinal vein occlusion. Lastly, to compare the results of this study with those in the literature and make recommendations on the treatment of retinal vein occlusion in the anti-vascular endothelial growth factor era. Methods: This was a consecutive case series of all patients with retinal vein occlusion who were treated with intravitreal anti-vascular endothelial growth factor injection at Hong Kong Sanatorium Hospital from August 2009 to February 2012. Re-injection was given as needed according to the best-corrected visual acuity and optical coherence tomography. Results: There were 24 eyes of 23 patients with central retinal vein occlusion and 26 eyes of 26 patients with branch retinal vein occlusion receiving anti-vascular endothelial growth factor therapy. For those with central retinal vein occlusion, the mean best-corrected visual acuity was 0.10 at baseline, 0.20 at 1 month post-injection (p = 0.001) and 0.52 at final follow-up (p = 0.02), at a mean follow-up of 12.1 months. Their mean central foveal thickness was reduced by more than 200 μm at both 1 month (p = 0.001) and final follow-up (p = 0.015). For those with branch retinal vein occlusion, the mean best-corrected visual acuity was 0.33 at baseline, 0.48 at 1-month post-injection (p = 0.046) and 0.55 at final follow-up (p = 0.014), at a mean follow-up of 11.5 months. Their mean central foveal thickness was reduced by more than 100 µm at both 1 month (p = 0.003) and final follow-up (p = 0.007). Neither neovascular nor injection-related complication was noted in all compliant patients. No significant difference in efficacy was found between ranibizumab and bevacizumab. The mean number of injections was 5.6 and 3.4 for those with central retinal vein occlusion and branch retinal vein occlusion, respectively. Conclusion: Intravitreal anti-vascular endothelial growth factor injection given as needed is safe and effective in terms of visual outcome, reduction of macular edema, and prevention of complications. The injection regimen should be individualized based on clinical status, patient expectation, and financial affordability, with consideration of adjuvant treatment.