Short-term Effects of Intravitreal Dexamethasone Implant on Choroidal Structure in Eyes with Refractory Diabetic Macular Edema

Abstract

Objectives: The objective of the study was to evaluate choroidal structural changes after intravitreal dexamethasone implant (IDI) in eyes with diabetic macular edema (DME) refractory to antivascular endothelial growth factor (VEGF) therapy. Methods: Twenty-three eyes of 14 patients with DME refractory to anti-VEGF therapy were included in this retrospective study. Detailed ophthalmological examinations were recorded, and optical coherence tomography images were obtained before and 3 months after IDI. Choroidal images were binarized into the luminal area and total choroidal area. Subfoveal choroidal thickness and choroidal vascularity index (CVI) were calculated. Results: The mean best-corrected visual acuity (BCVA) and central macular thickness (CMT) were improved significantly (from 0.94 to 0.81 LogMAR, p=0.02, and from 464 to 371 µ, p=0.01, respectively) after IDI. There were no significant changes in both SCFT and CVI at the end of the follow-up period (from 446.3 to 428.8 µ, p=0.51 and from 63.1 to 63.7 p=0.35, respectively). Conclusion: IDI in eyes with DME refractory to anti-VEGF therapy improves BCVA and CMT but has no significant effect on SCFT and CVI in the short term.