Sustained delivery fluocinolone acetonide vitreous implants: long-term benefit in patients with chronic diabetic macular edema

Purpose: To present the safety and efficacy of intravitreal implants releasing 0.2 μg/day fluocinolone acetonide (FAc) in patients with chronic versus nonchronic diabetic macular edema (DME). To assess ocular characteristics, anatomic changes, and re-treatment and ancillary therapies that may explain the differential treatment effect seen with intravitreal implants releasing FAc 0.2 μg/day in patients with chronic and nonchronic DME. An overall benefit-to-risk assessment for the FAc 0.2-μg/day and FAc 0.5-μg/day doses has been reported previously.

Design: Preplanned subgroup analysis of chronic (duration of diagnosis, ≥3 years) and nonchronic (duration of diagnosis, <3 years) DME in patients from 2 randomized, sham injection-controlled, double-masked, multicenter clinical trials.

Participants: Patients with persistent DME despite 1 or more macular laser treatment were randomized 1:2:2 to sham injection (n = 185), FAc 0.2 μg/day (n = 375), or FAc 0.5 μg/day (n = 393).

Methods: Patients received study drug or sham injection and after 6 weeks were eligible for rescue laser. Based on re-treatment criteria, additional masked study drug could be given after 1 year.

Main outcome measures: Percentage of patients with improvement of 15 letters or more from baseline. Secondary outcomes included other parameters of visual function and foveal thickness.

Results: At month 36, the difference between FAc 0.2 μg/day and sham control in the percentage of patients who gained 15 letters or more was significantly greater in chronic DME patients (FAc 0.2 μg/day, 34.0% vs. sham, 13.4%; P<0.001), compared with patients with nonchronic DME (FAc 0.2 μg/day, 22.3% vs. sham, 27.8%; P = 0.275). The greater response in patients with chronic DME was not associated with baseline ocular characteristics, changes in anatomic features, or differences in re-treatment or ancillary therapies. The ocular adverse event profile for FAc 0.2 μg/day was similar regardless of DME duration.

Conclusions: This is the first published analysis correlating duration of diagnosis of DME with treatment effect. In patients with chronic DME, FAc 0.2 μg/day provides substantial visual benefit for up to 3 years and would provide an option for patients who do not respond to other therapy.