Short-term effect of intravitreal dexamethasone implant in refractory diabetic macular edema

Purpose: To evaluate the short-term effects (hours-days) of intravitreal dexamethasone implant (IDI) in eyes with diabetic macular edema (DME) refractory to anti-vascular endothelial growth factor (VEGF) injections. Methods: This was a prospective, single-arm, interventional clinical series. Eyes with DME and 3-9 injections of ranibizumab without a good response were included. Patients underwent a single IDI. Best-corrected visual acuity (BCVA) measurement, complete ophthalmic evaluation, and spectral-domain optical coherence tomography (SD-OCT) were performed at baseline, 2 hours, 3 hours, 24 hours, 7 days, and 1 month. The main outcomes were change in central retinal thickness (CRT) on SD-OCT and BCVA. Results: Fifteen eyes of 15 patients were included. Mean CRT decreased rapidly after treatment from 515.87 µm ± 220.00 µm at baseline to 489.60 µm ± 176.53 µm after 2 hours (p=0.126), and 450.13 µm ± 163.43 at 24 hours (p=0.006). Change in BCVA was from 0.85 ± 0.44 logMAR baseline to 0.58 ± 0.37 log MAR at 1 month (p=0.003) Conclusions: Eyes treated with IDI showed significant decrease in CRT detectable 1 day after injection. In some patients, the effect could be observed 3 hours post-implantation. Trial registration: Clinicaltrials.gov NCT05736081. Registeres 20 February 2023, Retrospectively registeres. https://clinicaltrials.gov/ct2/show/NCT05736081