Effect of dexamethasone intravitreal implant for refractory and treatment-naive diabetic macular edema in Taiwanese patients

Background: Dexamethasone (DEX) implant has been shown to improve visual and anatomic function in patients with diabetic macular edema (DME). The purpose of this study was to investigate the efficacy and safety of DEX implant between refractory and naive eyes with DME. Methods: We retrospectively reviewed data from pseudophakic patients with center-involved DME who received DEX implant (1 + as needed retreatment) from May 2015 to May 2017. Baseline clinical characteristics, changes in best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were analyzed and compared between the two groups. Adverse events were recorded. Results: Thirty-four eyes of 31 patients refractory to anti-vascular endothelial growth factor agents and 41 eyes of 38 treatment-naive patients were reviewed. Baseline characteristics were comparable between the two groups (p > 0.05). In the refractory eyes, significant improvements in both BCVA and CFT were observed at 1 month post DEX implant and sustained throughout 6 months. Mean change from baseline in BCVA at 6 months was -0.17 +/- 0.35 logMAR (7.29 +/- 16.22 letters) and 155.44 +/- 112.67 mu m in CFT. Similar trends of improvement were seen in treatment-naive eyes; however, the visual improvement (-0.30 +/- 0.29 logMAR [16.42 +/- 14.38 letters]) was significantly better than the refractory group, with significantly less injections (1.54 +/- 0.49 versus 1.82 +/- 0.38, p = 0.007). Between-group changes in CFT were comparable. No serious ocular complications occurred, and about a quarter of the patients had elevated intraocular pressures that were manageable with topical medications. Conclusion: To our knowledge, this was the first study comparing DEX implant between treatment-naive and refractory Asian patients with DME. Intravitreal DEX implant can effectively treat refractory and treatment-naive patients with DME. In addition, superior visual outcomes were observed in the naive group comparing to the refractory group following DEX implant treatment in Taiwanese pseudophakic eyes with DME.

Automated summary

This study compared the efficacy and safety of Dexamethasone implant between treatment-naive and refractory Asian patients with diabetic macular edema. The results showed that DEX implant effectively treated both refractory and treatment-naive patients with DME, with superior visual outcomes observed in the treatment-naive group. The study also found that there were no serious ocular complications, and elevated intraocular pressures were manageable with topical medications in a quarter of the patients.