Bevordex: a multicentre randomized clinical trial of intravitreal dexamethasone versus intravitreal bevacizumab for persistent diabetic macular oedema

Purpose: Intravitreal injections of slow-release steroids, such as dexamethasone (Ozurdex), and inhibitors of Vascular Endothelial Growth Factor, such as bevacizumab (Avastin), have both been shown to be efficacious for center-involving diabetic macular edema (DME). We are conducting the first head to head randomized clinical trial of Ozurdex versus Avastin for DME. Here we present the 12 months results of the 2 year study.

Methods: This Phase II, prospective, multicentre, randomized, single-masked clinical trial was performed in 4 Australian sites, Clinicaltrial.gov#NCT01298076. We enrolled 88 eyes of 61 patients, of which 42 eyes were randomized to receive Avastin 4 weekly and 46 to Ozurdex 4 monthly, both pro re nata. The primary outcome was the proportion of eyes that improved by 10 LogMAR letters. Secondary outcomes included mean change in visual acuity (VA), injection frequency, central macular thickness (CMT) and adverse events. Results were analyzed using linear regression with generalized estimation equations methods to account for between eye correlation.

Results: VA improvements of 10 or more letters were found in 17 of 42 (40%) eyes treated with Avastin compared with 18 of 46 (39%) Ozurdex treated eyes (p=0.83). None of the 42 Avastin eyes lost 10 or more letters, whereas 5 of 46 (11%) Ozurdex did, mostly due to unoperated cataract. The mean improvement in VA was 8.9 letters, (95% confidence interval [CI], 6.27-11.6) for Avastin treated eyes and 5.6 (95% CI, 0.90-10.4) for Ozurdex eyes (p=0.24). The mean CMT at 12m was significantly greater for Avastin than Ozurdex eyes (380.6 vs.285.0 micon, p=0.007). Avastin eyes received a mean of 8.8 injections vs 2.8 for Ozurdex eyes. Of 24 patients with both eyes in the study that received both drugs, 11 (46%) preferred Ozurdex, 8 (33%) preferred Avastin and 5 (21%) had no preference.

Conclusions: Both Ozurdex and Avastin can improve vision in eyes with diabetic macular edema. We found no significant difference between the 2 groups with respect to vision gain. While more Ozurdex eyes lost vision, the mean VA gain was not statistically different between the 2 groups. Ozurdex generally achieved better anatomical outcomes with substantially fewer injections. The 2-year analysis of this study will include the effect of steroid-induced cataract and its removal.