Rapid response to dexamethasone intravitreal implant in diabetic macular edema

Purpose: To evaluate the early effects of dexamethasone (DEX) intravitreal implants in patients with diabetic macular edema (DME). Methods: This was a prospective, single-arm, interventional clinical series. Eighteen patients (18 eyes) with chronic/recalcitrant or naive DME were included. Patients underwent single DEX intravitreal implant. Clinical assessments, including ophthalmologic examination, central retinal thickness (CRT) measurement by spectral-domain optical coherence tomography (SD-OCT) scan, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were carried out at baseline, 1-3 hours, and then 3, 7, and 30 days after treatment. The main outcome was change in CRT on SD-OCT, while secondary outcome measures included visual acuity (VA) and changes in IOP following implant. Results: Mean CRT significantly decreased from 565 ± 171 µm at baseline to 310 ± 89 µm at end of follow-up (p<0.001), with reduction becoming evident 1-3 hours after injection. Mean BCVA also significantly improved 7 days and 30 days after treatment up to 0.14 logMAR (p<0.05). All patients had a controlled IOP after the injection with only 1/18 eyes having a transient increase in IOP during follow-up. Conclusions: This is the first study showing very early effects of DEX implants on CRT reduction and VA improvement in DME.