Duration of Action of Intravitreal Ranibizumab and Bevacizumab in Exudative AMD Eyes Based on Macular Volume Measurements

Background/Aims: We use sequential macular volume and central foveal point thickness (CFPT) measurements on optical coherence tomography (OCT) to determine the efficacy and duration of action of ranibizumab vs. bevacizumab in wet age-related macular degeneration (AMD). Methods: Retrospective chart review of patients who received their first treatment of intravitreal ranibizumab or bevacizumab for exudative AMD. We identified 316 patients (202 ranibizumab;114 bevacizumab) who received 823 injections (313 ranibizumab;510 bevacizumab). 74 patients had pre and post-treatment OCTs performed to determine CFPT and macular volume changes. Results: Ranibizumab caused a significant reduction in CFPT (278±84 before treatment vs. 227±80 microns after treatment; p=0.001) and macular volume (7.22±0.96 vs. 6.69±0.74 mm; p=0.002). Intravitreal bevacizumab caused a similar reduction in CFPT (288±94 vs. 220±55 microns; p=.008) and macular volume (7.36±1.08 vs. 6.50±0.42 mm; p<0.001). The average duration of action was 74.0±19.1 days for ranibizumab compared to 101.8±16.6 days for bevacizumab (p=0.036; t-test). The ratio of the relative duration of action of bevacizumab versus ranibizumab was 1.40±0.19. Conclusions: Both drugs ar