Long-term Treatment Effect of Intravitreal Ant-VEGF in Branch Retinal Vein Occlusion

Retinal vein occlusion (RVO) is the second leading cause of retinal vascular disease in patients older than 50 years.The prevalence varies from 0.7% to 1.6% in the literature.

Visual recovery depends on ischemic damage of the retina, the occurence of macular edema (ME) and the development of neovascular glaucoma. The occurence of ME is the main reason for visual loss and frustrates visual recovery among patients with both central or branch RVO.

Therapeutic options that have been used and discussed over the years are the treatment with anticoagulants, fibrinolytics, corticosteroids, acetazolamide and isovolemic haemodilution. Furthermore, surgical options like vitrectomy and radial optic neurotomy were used. Panretinal photocoagulation and grid pattern photocoagulation had established as additional tool to induce chorioretinal anastomosis. Nevertheless, the effectiveness and the evidence of these different treatment options could not be verified and remains mostly unknown.

Nowadays, intravitreal anti-VEGF application had become the treatment of choice for ME secondary to RVO. Multi-center studies have already shown the effectiveness of anti-VEGF treatment to reduce intraretinal fluid and retinal hemorrhages (BRAVO, CRUISE). Unfortunately, often high numbers of re-treatments become necessary over the years. In our knowledge, there are no reports showing more than 3 years treatment effects of antiangiogenic drugs in patients with BRVO. However, the results of treatment effect longer than 3 years are important, as the mean age \< 70 years with an onset of BRVO has been estimated in about 60% of all cases. In addition, most patients with regard to the application of anti-VEGF treatment in real clinical setting, there is only rare experience concerning need of optimum time duration for follow-up at the departments. Hence, the present study aimed to evaluate the long-term clinical outcomes, safety and therapeutic benefit of a flexible dosing regimen of intravitreal anti-VEGF therapy in patients with ME secondary to BRVO.