Efficacy of dexamethasone intravitreal implant in diabetic macular edema

Abstract

Purpose: To report the results of intravitreal dexamethasone implant (Dex-I) injection in the treatment of diabetic macular edema (DME).

Methods: Retrospective, interventional case series. Eyes that received Dex-I for decreased visual acuity as the result of persistent DME were included in a retrospective chart review. The main outcome measures were visual acuity (VA) and central macular thickness (CMT) at 2 and 4 months after injection. Secondary outcome measures included changes in intra-ocular pressure (IOP) and analysis of therapeutic response in sub-groups.

Results: 38 eyes of 33 consecutive diabetic patients were included (mean age : 62 years). The mean duration of DME was 28 months (range 6-60). Twenty eight patients (33 eyes) had received previous treatments for DME (intravitreal injection of anti-vascular endothelial growth factor, steroids or laser photocoagulation), including 11 eyes with previous vitrectomy. Five eyes were treatment-naïve. All eyes showed a significant decrease of CMT with median change of -223 µm (-57 à -468 µm) at 2 months ; between 2 and 4 months, macular thickness increased significantly in 76% of cases, overcoming baseline thickness in 24% of eyes and concomittent of a loss of vision in 36% of cases. The median VA gain was 5 ETDRS letters [-15 to 21] at 2 months and 3 letters [-11 to 27] at 4 months. A gain of more than 10 letters was observed in 27 % of cases at 2 months and 24% at 4 months. Eight eyes (21%) developed a transient IOP increase 2 months after injection, which was successfully managed with medical treatment.

Conclusions: At 2 months, I-Dex treatment allowed systematic anatomic improvement in all patients, and fonctional improvement in more than half cases, with good safety. However, recurrence of edema was observed in 76% of cases at 4 months, leading to re-treatment in more than one third of cases.

Keywords: 499 diabetic retinopathy • 585 macula/fovea • 505 edema