Objective: To report the 2-year outcomes of the BOLT study, a prospective randomized controlled trial evaluating intravitreous bevacizumab and modified Early Treatment Diabetic Retinopathy Study (ETDRS) macular laser therapy (MLT) in patients with persistent clinically significant macular edema (CSME).
Methods: In a 2-year, single-center, randomized controlled trial, 80 patients with center-involving CSME and visual acuity of 20/40 to 20/320 were randomized to receive either bevacizumab or MLT.
Primary outcome: difference in ETDRS best-corrected visual acuity (BCVA) between arms.
Secondary outcomes: mean change in BCVA, proportion gaining at least 15 and at least 10 ETDRS letters, losing fewer than 15 and at least 30 letters, change in central macular thickness, ETDRS retinopathy severity, and safety outcomes.
Results: At 2 years, mean (SD) ETDRS BCVA was 64.4 (13.3) (ETDRS equivalent Snellen fraction: 20/50) in the bevacizumab arm and 54.8 (12.6) (20/80) in the MLT arm (P=.005). The bevacizumab arm gained a median of 9 ETDRS letters vs 2.5 letters for MLT (P=.005), with a mean gain of 8.6 letters for bevacizumab vs amean loss of 0.5 letters for MLT. Forty-nine percent of patients gained 10 or more letters (P=.001) and 32% gained at least 15 letters (P=.004) for bevacizumab vs 7% and 4% for MLT. Percentage who lost fewer than 15 letters in the MLT arm was 86% vs 100% for bevacizumab (P=.03). Mean reduction in central macular thickness was 146 μm in the bevacizumab arm vs 118 μm in the MLT arm. The median number of treatments over 24 months was 13 for bevacizumab and 4 for MLT.
Conclusions: This study provides evidence supporting longer-term use of intravitreous bevacizumab for persistent center-involving CSME.
Application to clinical practice: Improvements in BCVA and central macular thickness seen with bevacizumab at 1 year were maintained over the second year with a mean of 4 injections.
Trial registration: eudract.ema.europa.eu Identifier: 2007-000847-89