Purpose: To determine whether a dexamethasone intravitreal implant 0.7 mg (dexamethasone delivery system [DDS], Ozurdex) combined with bevacizumab 1.25 mg (Avastin) provides greater benefit than bevacizumab monotherapy in eyes with diabetic macular edema with incomplete response to multiple antivascular endothelial growth factor injections.
Methods: Eyes with diabetic macular edema were randomly assigned to receive combination therapy (bevacizumab plus DDS) or bevacizumab monotherapy. Combination therapy eyes received intravitreal bevacizumab at baseline, DDS at Month 1, and subsequent DDS (at Months 5 and 9), whereas monotherapy eyes received bevacizumab (monthly) if indicated. Eyes were eligible for retreatment if the central subfield thickness measured >250 μm, and Early Treatment of Diabetic Retinopathy Study visual acuity was <80 letters (20/25).
Results: Forty eyes of 30 patients were enrolled. The mean visual acuity changes from baseline to 12 months were similar in the 2 groups (combined: +5.4 letters; bevacizumab: +4.9 letters; difference = 0.2 letters, 95% confidence interval = -5.9 to 6.3; P = 0.75). The mean reduction in central subfield thickness was greater in the combination group (-45 μm vs. -30 μm, difference = 69 μm, 95% confidence interval = 9-129; P = 0.03) and more patients in the combination group had central subfield thickness <250 μm. The combined treatment group received three fewer supplemental injections of bevacizumab, but this was counterbalanced by the need for an average of 2.1 DDS injections.
Conclusions: The dexamethasone implant combined with bevacizumab significantly improves visual acuity and significantly improves macular morphology in eyes with refractory diabetic macular edema, although visual acuity changes are not superior to continued bevacizumab monotherapy.