Effects of intravitreal aflibercept and ranibizumab on retinal vessel diameter measured using fluorescein angiography

Purpose To investigate the effect of intravitreal (IVT) aflibercept and ranibizumab on retinal vessel diameter in patients with neovascular age‐related macular degeneration (N‐AMD). Methods Forty eyes of 40 consecutive participants with treatment‐naïve N‐AMD were included. Two groups of 20 eyes received three consecutive monthly treatments of IVT aflibercept or ranibizumab. Retinal vessel diameter was measured using fluorescein angiography (FA) before the first IVT injection and 1 month after the third injection. Central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) were calculated to represent average retinal vessel diameters. Results Retinal vessel diameter significantly decreased in aflibercept‐treated patients; CRAE and CRVE reduced from 106.7 ± 22.9 μm to 96.1 ± 24.1 μm (P = 0.028) and from 148.8 ± 19.6 μm to 140.8 ± 19.6 μm (P = 0.003), respectively. Pre‐injection and post‐injection arteriovenous ratios were 0.71 ± 0.08 and 0.71 ± 0.11, respectively (P = 0.733). However, retinal vessel diameter was not significantly reduced in ranibizumab‐treated patients; CRAE changed from 107.1 ± 23.3 μm to 104.4 ± 22.0 μm (P = 0.073) and CRVE from 139.0 ± 13.8 μm to 139.2 ± 14.2 μm (P = 0.794). Pre‐injection and post‐injection arteriovenous ratios in the ranibizumab‐treated group were 0.74 ± 0.14 and 0.72 ± 0.14, respectively (P = 0.163). Conclusions IVT aflibercept treatment had a significant vasoconstrictive effect in eyes treated for N‐AMD; on the other hand, IVT ranibizumab did not significantly affect retinal vessel diameter. The aflibercept‐mediated reduction in diameter was not vessel‐specific.