Contrast sensitivity outcomes in the ABC Trial: a randomized trial of bevacizumab for neovascular age-related macular degeneration

Abstract

Purpose: To report the impact of intravitreous bevacizumab therapy on contrast sensitivity in patients with neovascular age-related macular degeneration (nAMD).

Methods: This was a prospective, multicenter, double-masked, randomized, controlled trial of 131 patients with nAMD. The patients with nAMD had received intravitreal bevacizumab (n = 65) or standard therapy (n = 66) in the study eye with a 6-week cycle of assessment. The bevacizumab treatment was 1.25 mg/0.05 mL, given as three initial treatments with further retreatment as needed according to standard retreatment criteria and a 1-year (54-week) follow-up. Contrast sensitivity was determined during the study using a Pelli-Robson chart.

Results: At the week-54 examination, bevacizumab-treated patients were more likely to gain at least 6 letters or more of contrast sensitivity than the patients receiving standard care (23 [35.4%] versus 10 [15.2%], P = 0.009). In addition the bevacizumab-treated patients were less likely to lose 6 or more letters with a better mean letter change at week 54 than the patients receiving standard care (3 [4.6%] versus 14 [21.2%], and +4.0 versus -0.7 letters; P < 0.05 for both comparisons).

Conclusions: Consistent with the visual acuity outcomes, bevacizumab improved the chances of a clinically relevant gain in contrast sensitivity in the study population. Given the association between contrast sensitivity and visual disability, the beneficial effects of bevacizumab therapy on contrast sensitivity outcomes are expected to have a favorable impact on patients' daily activities. (www.controlled-trials.com number, ISRCTN83325075.).