Outcomes of Intravitreal Dexamethasone Implant in the Treatment of Recalcitrant Diabetic Macular Edema

OBJECTIVES: To investigate the efficacy and safety of intravitreal dexamethasone (OZURDEX®) implantation in patients with recalcitrant diabetic macular edema. MATERIALS AND METHODS: This is a retrospective non-randomized study of patients who underwent intravitreal dexamethasone implantation for recalcitrant diabetic macular edema. Main outcome measures included changes in best corrected visual acuity (BCVA), central macular thickness (CMT), and incidence of ocular side effects. RESULTS: Fifty-seven eyes of thirty-eight patients (20 females, 18 males; mean age 65±7 years) were included in the study. The mean hemoglobin A1c level was 7.9±1.7%. Before entering the study, patients had undergone 5.71±3.40 anti-vascular endothelial growth factor (anti-VEGF) and 3.44±2.46 intravitreal triamcinolone acetonide injections. The mean duration of diabetes and diabetic macular edema was 17.2±6.4 years and 60.2±17.6 months, respectively. At baseline, mean CMT was 506.76±166.74 µm, and the mean BCVA was 0.68±0.38 LogMAR. Mean CMT significantly decreased to 341.36±146.26 µm (p<0.001), 324.41±114.58 µm (p<0.001), and 384.82±151 µm (p<0.001) at 1, 3, and 4 months of follow-up and increased again to 462.29±152.87 µm at 5 months. Sixteen eyes (28%) received second injections after mean of 7.4±2.3 months and mean CMT was again significantly decreased at 7, 8, and 9 months. Significant improvement in mean BCVA (0.54±0.41 LogMAR; p<0.001) occurred only at 1 month after implantation. However, subgroup analysis revealed significant BCVA improvement in the pseudophakic group at 1, 3, and 4 months. Among phakic patients, 50% showed cataract progression and 28% had elevated intraocular pressure increase which was managed medically. CONCLUSION: Intravitreal dexamethasone implantation was effective for the first 4 months in eyes with recalcitrant diabetic macular edema. However, it is hard to displace anti-VEGF agents as first-line therapy due to steroid-related complications.