Quantitative OCT Subanalysis of Eyes with Choroidal Neovascularization Switched from Multiple Injections of Bevacizumab or Ranibizumab to Intravitreal Aflibercept

Abstract

Purpose: To assess the therapeutic response after switching from multiple injections of bevacizumab or ranibizumab to aflibercept in the eyes with neovascular age-related macular degeneration (AMD).

Methods: Thirty-one eyes of 31 patients with neovascular AMD were collected retrospectively in this IRB approved study. To be included in the analysis, subjects were required to have been deemed as suboptimal responders by the treating physician despite multiple injections of bevacizumab or ranibizumab, and as a result, were switched to aflibercept therapy. Suboptimal response was defined as the presence of at least some intraretinal, subretinal, or sub- retinal pigment epithelial (RPE) fluid 4-6 weeks after therapy despite multiple monthly (>3) injections. Volume spectral domain optical coherence tomography (SD OCT) scans that were taken on the last visit just prior to switching therapies (within 4-6 weeks of the switch), at the time of the switch, at least 4 weeks after switching , and after three aflibercept injections were exported and analyzed using validated reading center OCT grading software (known as OCTOR). Following segmentation, the volumes of the neurosensory retina, subretinal fluid (SRF), and pigment epithelial detachment (PED) were computed and compared at the various time points. In addition, mean ETDRS visual acuity of the patients at those visits were compared.

Results: After the last injection of bevacizumab or ranibizumab neurosensory retinal volume increased by 0.10 ± 0.56 mm³, SRF volume by 0.07 ± 0.29 mm³, and PED volume by 0.19 ± 0.49 mm³ ; but following switching to aflibercept, a decrease of 0.32 ± 0.4 mm³ in neurosensory retinal volume, 0.13 ± 0.32 mm³ in SRF volume, and 0.67 ± 0.89 mm³ in PED volume was observed; all these decreases were statistically significant (p=0.01, 0.04, and 0.001, respectively). While the mean ETDRS visual acuity after the last injection of bevacizumab or ranibizumab was decreased from 65.3 ± 12.3 to 64.5 ± 14, it was increased to 68.3 ± 10.8 after switching (p=0.04).These favorable outcomes were sustained after three monthly injections of aflibercept.

Conclusions: Switching to aflibercept therapy in eyes with persistent fluid after multiple intravitreal injections of bevacizumab or ranibizumab was associated with an early reduction in all fluid compartments and improvement in visual acuity.