To study the efficacy of intravitreal injection (IVI) of dexamethasone implant as second-line treatment in patients with resistant chronic diabetic macular edema nonresponsive to 6 monthly consecutive IVI of ranibizumab.
A retrospective study was conducted over 9 months. Best-corrected visual acuity and central macular thickness were noted. Patients with best-corrected visual acuity ≤20/40 using Snellen chart, central macular thickness ≥300 μm, and poor response to 6 monthly consecutive IVI of ranibizumab were included. Patients received IVI of dexamethasone implant and were examined at 1, 3, 6, and 9 months.
Thirteen eyes of 12 patients were included (6 men and 6 women; mean age, 64 ± 7.8 years). Best-corrected visual acuity increased by a mean of 5.58 letters at Month 1 (P = 0.017), 4.61 at Month 3 (P = 0.05), 4.61 at Month 6 (P = 0.042), and 5.77 at Month 9 (P = 0.017). Central macular thickness decreased from 594 μm to 402 μm at Month 1 (P = 0.0002), 428 μm at Month 3 (P = 0.002), 459 μm at Month 6 (P = 0.02), and 489 μm at Month 9 (P = 0.03). Mean number of dexamethasone IVI was 1.07. Two patients (15.3%) developed elevated intraocular pressure, and 1 patient was operated for cataract at 6 months (9% of phakic patients).
Intravitreal injection of dexamethasone implant seems as an effective second-line treatment in diabetic macular edema persistent after 6 monthly consecutive intravitreal ranibizumab injections in real life.