Long-term Stability of Vascular Endothelial Growth Factor Suppression Time Under Ranibizumab Treatment in Age-Related Macular Degeneration

Abstract

To determine intra-individual long-term stability of vascular endothelial growth factor (VEGF) suppression time in eyes with neovascular age-related macular degeneration (AMD) treated with ranibizumab. Nonrandomized, prospective clinical study. Eighty-three eyes of 83 patients with neovascular AMD undergoing intravitreal ranibizumab injections were included in the study. A total of 859 aqueous humor specimens were taken before each intravitreal ranibizumab injection. Vascular endothelial growth factor A was measured by multiplex bead analysis. Ranibizumab resulted in complete VEGF suppression within a mean period of 36.4 days (standard deviation ±6.7 days; range, 26-69 days). Intra-individual suppression time was stable within a period of up to 3 years. Among 859 VEGF measurements, only 5 (0.58%) deviated from this pattern. Nonsuppressed VEGF levels did not differ significantly between baseline and recurrence (68.0 pg/mL vs 69.3 pg/mL) and did not correlate with choroidal neovascularization size and lesion type. Both the long-term stability and the broad range of individual suppression times after ranibizumab injections would allow and justify adjustment of continuous injections individually in order to achieve permanent VEGF suppression in patients.