Limited Treatment Response during Follow-up after Switching to Aflibercept in Neovascular Age-related Macular Degeneration

Purpose: To investigate the limited response to aflibercept after switching to aflibercept in neovascular age-related macular degeneration (AMD). Methods: This retrospective study included 70 eyes with neovascular AMD that were initially treated with ranibizumab and then switched to aflibercept. The incidence and timing of the limited response to aflibercept were identified and visual outcome was compared between eyes with and without limited response. In addition, factors predictive of limited response were analyzed. Results: A limited response to aflibercept was noted in approximately 1/5 of the patients who underwent switching to aflibercept in neovascular AMD. Switching to aflibercept was performed at a mean of 16.2 +/- 12.7 months after diagnosis. During the mean 34.7 months of follow-up after switching, limited response was noted in 15 eyes (21.4%) at a mean of 22.0 +/- 13.9 months after switching. The degree of reduction in visual acuity was mean logMAR 0.34 +/- 0.41 in eyes with limited response and mean 0.06 +/- 0.20 in eyes without (p = 0.002). In addition, the duration between the diagnosis and the switching was shorter (p = 0.012), and the number of ranibizumab injections before switching was lower (p = 0.016) in eyes with limited response than in eyes without. Conclusions: Patients who showed limited response to aflibercept after switching to aflibercept showed a worse visual outcome. The probability of having a limited response is higher when the switching is performed earlier.