Self-Controlled Comparison of the Anatomical and Visual Response to Intravitreal Ranibizumab and Aflibercept in Treatment-Resistant Age-Related Macular Degeneration

Abstract

Purpose: To compare the initial 12 month anatomical and visual response to intravitreal ranibizumab with the subsequent 12 month response to aflibercept therapy in the same patient with treatment-resistant neovascular age-related macular degeneration (nAMD).

Methods: Self-controlled open-label case series of 39 nAMD patients resistant to prior ranibizumab treatment. Patients received 3 loading doses of aflibercept 1 month apart followed by injections every 2 months up to 12 months. The medical records of the same patients were retrospectively reviewed for the 12 months following initial ranibizumab therapy. All patients underwent monthly ophthalmic examination including best corrected visual acuity (VA) and either time-domain or spectral-domain optical coherence tomography (OCT) to measure central macular thickness (CMT). Snellen VA was converted to Early Treatment in Diabetic Retinopathy Study (ETDRS) letters in ranibizumab treatment for comparison. Mean changes in VA and CMT were assessed between baseline and each visit. Mean differences between the responses ranibizumab compared to aflibercept were assessed after 3 loading doses and after 12 months.

Results: Mean VA at baseline ranibizumab was not significantly different from VA at baseline aflibercept (64.2 vs. 58.5 letters respectively, p=0.1). The mean improvement in VA after 3 loading doses was significantly less with ranibizumab compared to aflibercept (3.3 vs. 7.0 letters respectively, p=0.02), the difference in the improvement between the 2 treatments was not significant after 12 months (4.4 vs. 5.1 letters respectively, p=0.8). Mean CMT at baseline ranibizumab was significantly lower than at baseline aflibercept (312.0 vs. 450.9 m respectively, p<0.001). After 3 loading doses, mean reduction in CMT was significantly lower with ranibizumab compared to aflibercept therapy (30.1 vs. 181.8µm respectively, p<0.001). This difference remained at the 12 month visit (20.7 vs. 89.4µm respectively, p=0.05). The number of aflibercept injections over 12 months was capped at 8 injections, whilst the mean number of ranibizumab injections was 11.4.

Conclusions: Intravitreal aflibercept was found to be more effective than ranibizumab in improving anatomical outcomes and produced greater initial visual gain in this case series.

Keywords: 466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • 688 retina • 700 retinal neovascularization