Abstract
Purpose: :
To report the findings at one year of a study comparing repeated intravitreal bevacizumab (ivB) and modified ETDRS macular laser therapy (MLT) in patients with persistent clinically significant diabetic macular edema (CSME).
Methods: :
Prospective, randomised, masked, single centre, two year, 2-arm clinical trial of 80 eyes of 80 patients with centre-involving CSME and at least one prior MLT, were randomised to either ivB (1.25mg in 0.05ml every 6 weeks; with a minimum of 3 injections and a maximum of 9 in the first 12 months), or to MLT (4 monthly modified ETDRS macular laser photocoagulation; with a minimum of 1 treatment and a maximum of 4 in the first 12 months). Primary endpoint was the difference in ETDRS best-corrected visual acuity (BCVA) at 12 months between the bevacizumab and laser arms. Secondary endpoints included the proportion of patients with a gain of ≥ 15 ETDRS letters, loss of < 15 ETDRS letters, and loss of ≥ 30 ETDRS letters; and reduction in central macular thickness (CMT) measured with optical coherence tomography (OCT).
Results: :
Forty-two patients were randomised to ivB and 38 to MLT. The baseline mean ETDRS BCVA in the bevacizumab group was 55.7 + 9.7 (range 34 to 69) and 54.6 + 8.6 (range 36 to 68) in the laser arm. The mean ETDRS BCVA at 12 months was 61.3 + 10.4 (range 34 to 79) in the bevacizumab group and 50.0 + 16.6 (range 8 to 76) in the laser arm (p=0.0006). The bevacizumab group gained a median of 8 ETDRS letters whilst the laser group lost a median of 0.5 ETDRS letters (p=0.0002). 11.9% (5/42) of patients in the bevacizumab group and 5.3% (2/38) in the laser arm (p=0.43) gained ≥ 15 ETDRS letters; with 31.0% (13/42) gaining ≥ 10 ETDRS letters in the bevacizumab group compared to 7.9% (3/38) in the laser arm (p=0.01). 97.6% (41/42) in the bevacizumab arm compared to 73.7% (28/38) in the laser group (p=0.002) lost < 15 ETDRS letters. At 12 months, in ivB subjects CMT decreased from 507 + 145um (range 281 to 900) at baseline to 378 + 134um (range 167 to 699) (p<0.001); whereas in laser subjects it decreased to a lesser extent, from 481 + 121um (range 279 to 844) to 413 + 135um (range 170 to 708) (p=0.02). The median number of injections in the ivB patients was 9 (interquartile range [IQR] 8, 9), and 3 (IQR 2, 4) laser treatments in the MLT patients. There was no evidence of an adverse effect of ivB on macular perfusion at 12 months and no thromboembolic events or deaths in the ivB group.
Conclusions: :
The study provides evidence to support the use of bevacizumab in patients with centre-involving CSME without advanced macular ischemia.1
Clinical Trial: :
www.ISRCTN.org ISRCTN41984498
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • diabetic retinopathy • vascular endothelial growth factor