Objective: To evaluate changes in central retinal sensitivity in patients with neovascular age-related macular degeneration after systemic bevacizumab (Avastin; Genentech, Inc., South San Francisco, CA) therapy.
Methods: For all eyes, the central 12 x 12 degrees visual field was recorded using the MP 1 Microperimeter (Nidek, Gamagori, Japan) at baseline and 1 week, 1 month, 3 months, and 6 months after initial treatment. Patients received systemic anti-vascular endothelial growth factor (VEGF) therapy with three initial bevacizumab infusions at 2-week intervals. Retreatment during follow-up was performed only in cases of choroidal neovascularization recurrence. Seven patients (12 eyes) received bevacizumab infusions at a dose of 5 mg/kg, and 7 patients (9 eyes), at a dose of 2.5 mg/kg.
Results: Of 41 stimulation points, a mean absolute scotoma of 15 missed stimulation points was measured at baseline, which decreased to 10 missed stimulation points at month 3 (-5; P = 0.005) and to 11 stimulation points at month 6 (-4; P = 0.106). The mean absolute scotoma size (in % of total tested area) decreased from 33% to 22% (-11%; P = 0.011) at month 3 and to 23% (-10%, P = 0.123) at month 6. Mean differential light threshold increased significantly throughout the observation period from 3.8 dB at baseline to 5.5 dB (+1.7 dB; P = 0.012) at month 6.
Conclusions: Systemic bevacizumab therapy induced a significant increase in mean retinal sensitivity at month 6 of follow-up and a significant decrease of mean absolute scotoma size at month 3. The MP 1 Microperimeter proved to be a valuable tool in the evaluation of functional benefits and retinal safety of anti-VEGF therapy with systemic bevacizumab.