Efficacy of dexamethasone intravitreal implant for the treatment of persistent diffuse diabetic macular edema

To investigate the efficiency and safety of a single injection of intravitreal dexamethasone implant in eyes with persistent diffuse diabetic macular edema (DME). In this retrospective study, 25 eyes of 20 patients, who underwent a single injection of intravitreal dexamethasone implant for the treatment of persistent diffuse DME, were reviewed. Main outcome measures included the changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT) from baseline at scheduled visits following injection. The mean BCVA showed improvement from baseline (0.97 ± 0.26 logMAR) at every visit; the difference was significant at day 7 (0.85 ± 0.3 logMAR, p = 0.003), month 1 (0.77 ± 0.32 logMAR, p < 0.001), month 3 (0.77 ± 0.34 logMAR, p = 0.001), and month 4 (0.85 ± 0.31 logMAR, p = 0.014). The mean CMT was significantly lower than baseline (616 ± 132 μm) at day 1 (518 ± 144 μm), day 7 (414 ± 134 μm), month 1 (306 ± 95 μm), month 3 (339 ± 88 μm), month 4 (420 ± 116 μm), and month 6 (494 ± 128 μm) following the injection (p < 0.001, for all). Thirteen eyes on the 4-month follow-up and ten eyes on the 6-month follow-up experienced recurrence of macular edema requiring retreatment. No serious ocular and systemic adverse events were observed. In patients with persistent DME, switching to intravitreal dexamethasone implant injection provides functional and anatomical improvement, and might be an effective therapeutic option for long-standing diffuse DME.