Incidence of anterior segment neovascularization during intravitreal treatment for macular edema secondary to central retinal vein occlusion

Purpose: To analyze the effects of injections of intravitreal triamcinolone acetonide (IVTA) and intravitreal bevacizumab (IVB) on the incidence rates of anterior segment neovascularization (ASN) and neovascular glaucoma (NVG) in patients with macular edema secondary to central retinal vein occlusion (CRVO). Methods: In this prospective, randomized, double-masked, sham-controlled study, 35 patients with macular edema following CRVO were randomized to intravitreal bevacizumab, intravitreal triamcinolone acetonide, or sham injections during the first 6 months of the study. The primary outcome was the incidence rate of ASN at month 6. The secondary outcomes were the mean changes from baseline in best-corrected visual acuity (BCVA) and central foveal thickness (CFT) on optical coherence tomography over time to month 12. Results: ASN developed in 8 (22.86%) eyes, including 5 (62.50%) eyes in the sham group and 3 (37.50%) eyes in the IVTA group, during 12 months of follow-up (p=0.009). BCVA differed significantly (p<0.05) among the groups only at month 1. CFT did not differ significantly (p<0.05) among the groups over 12 months. NVG required surgery and developed in one eye despite laser treatment. Conclusion: Early treatment with intravitreal antivascular endothelial growth factor therapy decreases the rates of ASN and NVG after CRVO.