The influence of anti-VEGF therapy on present day management of macular edema due to BRVO and CRVO: a longitudinal analysis on visual function, injection time interval and complications

The purpose of this study was to evaluate the impact of intravitreal bevacizumab injections on the management and outcome of patients affected by retinal vein occlusions, their effectiveness on morphological and functional parameters, the modalities of long-term management and the need for additional laser treatment due to ischemic retinal evolution. Patients diagnosed with branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO) had a comprehensive work-up including complete ophthalmic examination, fluorangiography (FA), optical coherence tomography (OCT), visual field testing (VFT), microperimetry (MP), and laser flare photometry (LFP). In case of BRVO, intraocular bevacizumab injection was performed if significant macular edema/visual deficit was still present 3 months after onset of occlusion and injections were started at presentation in case of CRVO. Post-injection follow-up examination including best corrected visual acuity (BCVA), intraocular pressure (IOP), LFP, OCT, MP, and VFT were performed monthly and recorded at the end of follow-up. Follow-up FA was performed between 12 and 18 months after diagnosis. Injections were repeated in case of recurrence of a significant central macular edema. Patients were subdivided into 2 groups according to number of injections: 1–4 injections or more than 4 injections. The proportion of resolved cases (no recurrence after a minimum follow-up of 12 months) was calculated and correlated with number of injections. In patients needing sustained injections, management modalities were recorded. The proportion of patients having needed laser photocoagulation treatment because of significant ischemic signs was recorded. Fifty-one patients were diagnosed with retinal vein occlusion between 2006 and 2012 at the Centre for Specialized Ophthalmic Care (COS) in Lausanne, Switzerland. Forty-four had enough data and were included in the study. Nine eyes were affected by CRVO and 35 were affected by BRVO. Mean BCVA at presentation was 0.24 ± 0.2 and improved to 0.81 ± 0.38 (p < 0.01) at 48 months. MP improved from 184.9 ± 92 to 362.5 ± 56.2 (p < 0.01) at 42 months follow-up. The number of injections varied from 1 to 25 (mean 5.5 ± 5.43). 31/44 eyes received 1–4 injections (group 1) of which all were recurrence free, with a follow-up of at least 1 years in all. 13/44 eyes received more than 5 injections (group 2) with functional and morphological parameters maintained in 9/13 but only 1/13 patients showed resolution. Rhythm of injection varied from one patient to another but 8/13 patients needing continuous injections had a constant time interval between injections. In 8/44 patients, laser photocoagulation had to be performed due to ischemic complications. The visual outcome using bevacizumab intravitreal injection was exceptionally good and functional parameters such as BCVA, MP, and VFT improved significantly. In about two-thirds of patients, resolution was obtained after 1–4 injections. In one-third of patients, continuous injections were necessary but a constant rhythm for re-injection for each patient could be established allowing to reduce to a minimum follow-up visits. The absence of significant side effects allowed to re-treat apparently without limitation achieving maintained visual function. FA monitoring for the detection of ischemic complications should not be neglected especially in cases where bevacizumab could be discontinued.