Purpose: The purpose of this study was to evaluate the early treatment response following systemic and intravitreal bevacizumab therapy in patients with neovascular age-related macular degeneration (AMD).
Patients and methods: In a prospective cohort study 12 eyes with neovascular AMD were treated with 5 mg/kg systemic bevacizumab, and 13 eyes with 1 mg intravitreal bevacizumab. Systemic therapy was given three times at 2-week intervals, intravitreal therapy up to three times at 4-week intervals. Patients were evaluated according to best corrected visual acuity (VA) and optical coherence tomography (OCT) at baseline as well as at week 1, week 4 and week 12 after therapy. Fluorescein angiography (FA) was performed at baseline and week 12.
Results: Systemic and intravitreal bevacizumab therapy showed a treatment response within one week. Visual acuity improved at week 1 by 4.9 letters from baseline in the systemic and by 6.9 letters in the intravitreal treatment group. Central retinal thickness (CRT), as measured by OCT decreased by 51.9 microm and 176.4 microm, respectively. At month 3 a persistent treatment effect was detectable. Mean gain in visual acuity was 11 letters in the systemic and 8.3 letters in the intravitreal group, CRT had decreased by 100 microm and 153.8 microm, respectively. Leakage as evaluated by FA was significantly reduced or absent in all patients.
Conclusion: The early treatment responses following systemic and intravitreal bevacizumab appear to be similar. Both groups show improvement in VA and decrease in CRT within 1 week and up to 3 months. Long-term follow-up is required to evaluate the safety and treatment durability of both treatment modalities using bevacizumab.