Effect of dexamethasone intravitreal implant in vitrectomized and nonvitrectomized eyes of Taiwanese patients with treatment-naive diabetic macular edema

Background/Purpose: Vitrectomy may affect intravitreal drug clearance and efficacy for treating diabetic macular edema (DME). This study aimed to evaluate functional and anatomical outcomes of intravitreal dexamethasone (DEX) implant for vitrectomized and nonvitrectomized eyes with treatment-naive DME in Taiwanese patients. Methods: In this retrospective single-center study, we reviewed treatment-naive patients who received DEX implant monotherapy for center-involved DME from January 2015 to May 2017. Retreatments were provided at least 4 months apart as needed. The primary outcomes included changes from baseline in best-corrected visual acuity (BCVA) and central foveal thickness (CFT) at Month 6. Adverse events were recorded. Results: Twenty-seven eyes in 27 patients had prior vitrectomy and 43 eyes in 41 patients without vitrectomy. Baseline data were comparable. Overall, the improvements in BCVA and CFT were significant by 1 month post-treatment and sustained throughout the study ( all p < 0.05). At Month 6, BCVA improved by 16.5 and 12.1 letters, and CFT reduced by 138.0 and 121.9 mm in vitrectomized and nonvitrectomized eyes, respectively, with a mean of 1.5 DEX implant injection. No significant differences in clinical outcomes were seen between the two groups (all p > 0.05). DEX implant injection was well tolerated. About 30% of patients had post-injection intraocular pressure value > 20 mmHg, and all were manageable with topical hypotensive agents, and no serious ocular complication was observed. Conclusion: In this 6-month retrospective study, intravitreal DEX implant was effective in Taiwanese patients with treatment-naive DME regardless of vitrectomy status. Copyright (C) 2020, Formosan Medical Association. Published by Elsevier Taiwan LLC.