The effect of Fluocinolone Acetonide Implant (Iluvien) in patients with diabetic macular edema (DME) with prior no, or sub-optimal response to Dexamethasone implants (INDEX Study)

Abstract

Purpose : Retinal Physicians typically assume the effect of steroid implants (Dexamethasone and Iluvien) is similar in patients with DME, however there is little evidence to support this due to their differing pharmacodynamic and pharmacokinetic properties.
INDEX is an exploratory prospective observational study evaluating the effect of Iluvien implants over 12-months in patients with chronic DME with documented prior no, or suboptimal response to Dexamethasone implant(s). We present the 6-month interim results.

Methods : Twenty patients with chronic DME who had previously received one or more Dexamethasone implants were recruited with a documented history of either 1) No response (less than 20% reduction in baseline central subfoveal thickness (CST) at 6 weeks) or 2) a suboptimal response (reversal of initial good response at 3 months with less than 20% reduction of baseline CST). Iluvien was administered and the patients followed for at least 12-months.
Outcome measures include structural and functional changes (changes in CST and best corrected visual acuity (BCVA) at 3 and 6 months) as well as changes in intraocular pressure (IOP).
Wilcoxon signed rank test with continuity correction was used to ascertain difference between baseline and the month 3 and 6 outcomes.

Results : Fifteen patients have completed 6 months follow-up to date. Mean age was 69.2 years, with chronic DME of 9 years mean duration). Patients had received a mean of 20.6 and 1.8 prior anti-VEGF injections and Dexamethasone implants respectively. Mean baseline BCVA improved from 62.2 to 68.1 (SD= 10.5) and 66.3 letters (SD=10.5) at 3 and 6 months respectively (p=0.01 and 0.03). Mean CST improved from 487 at baseline to 410.2 (SD=91) and 409.8 microns (SD= 104) at 3 and 6 months respectively (p=0.006 and 0.009). Mean IOP changed for 14.5 at baseline to 14.2 (SD=3.6) and 16.8 mmHg (SD= 2.5) at 3 and 6 months. (p= 0.02). No other adverse events were recorded.

Conclusions : The INDEX study 6-month interim results so far demonstrate a favorable structural and functional response to Iluvien in patients with DME with no or poor response to prior Dexamethasone implant. The results challenge the presumed link of efficacy of the two steroid implants. These patients could be offered an Iluvien implant to restore or maintain vision.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.