Ozurdex Shows Superiority Treating Diabetic Macular Edema
Anti-vascular endothelial growth factor agents are the criterion standard for diabetic macular edema.
Although treatment with anti-vascular endothelial growth factor (VEGF) agents is the criterion standard for diabetic macular edema (DME), a substantial proportion of eyes have persistent DME despite anti-VEGF therapy.
Indirect evidence indicates that persistent DME can cause permanent vision loss, possibly because the edema causes prolonged disruption of the retinal architecture, which results in irreversible retinal damage. Therefore, the subset of eyes with persistent DME unresponsive to anti-VEGF agents require an alternative to anti-VEGF therapy.
To compare monthly intravitreal injections of the anti-VEGF agent bevacizumab (Avastin) with quarterly injections of an intravitreal implant that delivers the corticosteroid dexamethasone for 3 months (Ozurdex), investigators at the Indiana University School of Medicine and the Midwest Eye Institute in Indianapolis, Indiana, did a single-center, randomized, subject-masked study in 50 eyes with persistent diabetic macular edema.
Persistence was defined as central subfield thickness (CST) >340 μm despite at least 3 injections of anti-VEGF agents within 5 months. At baseline, best-corrected visual acuity and CST were similar in both groups. After 7 months, monthly intravitreal injections of bevacizumab, 1.25 mg/0.05 mL, and intravitreal implantation of Ozurdex (containing dexamethasone, 0.7 mg) at baseline and every 3 months thereafter produced similar final best-corrected visual acuities.
However, corticosteroid dexamethasone resulted in a final CST that was significantly lower than that for bevacizumab (336 ± 89 μm vs. 471 ± 157 μm, respectively; P = 0.001), and corticosteroid dexamethasone reduced CST significantly more than bevacizumab (−122 ± 120 μm vs. −13 ± 105 μm). Moreover, corticosteroid dexamethasone therapy required approximately 60% fewer injections than bevacizumab therapy (2.7 ± 0.5 vs. 7.0 ± 0.2, P < 0.001). The investigators noted that fewer injections may require fewer patient visits.
They also noted that the corticosteroid dexamethasone group had no recurrent edema at any visit. Nevertheless, a greater proportion of patients in the corticosteroid dexamethasone group had an elevation in intraocular pressure and needed anti-glaucoma agents. However, none of the eyes in either treatment group needed laser therapy or surgery for glaucoma.