PURPOSE: To assess the efficacy and safety of 0.19-mg fluocinolone acetonide (FAc) intravitreal implant (Iluvien®) in treating chronic postoperative cystoid macular edema (PCME) after pars plana vitrectomy. DESIGN: Retrospective multicentric case series in clinical settings. SUBJECTS: Patients with chronic PCME who underwent vitrectomy in tertiary care centers in France. All eyes had a documented good response to the DEX implant prior to FAc implantation. METHODS: Review of charts and OCT scans of patients treated with a FAc intravitreal implant. MAIN OUTCOME MEASURES: The primary endpoints were the best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Secondary endpoints were the intraocular pressure (IOP); proportion of patients maintaining a BCVA ≥20/40; need for additional non-study treatment; differences between eyes that underwent a single and multiple surgeries and OCT biomarkers of better BCVA. RESULTS: Forty-nine eyes of 49 patients with a mean follow-up of 24.5 ± 3.9 months were included. The mean BCVA increased from 0.40 ± 0.26 logMAR at baseline to 0.32 ± 0.24 logMAR at month 24 (M24) (p=0.0035). The mean CRT decreased from 409.37 ± 139.43 μm at baseline to 340 ± 91 μm at M24 (p=0.0001). The mean IOP was 14.0 ± 4 mmHg at baseline and remained stable at 14.03 ± 4.1 mmHg at M24 (p=0.99). During the follow-up, the IOP exceeded 21 mmHg in 9 eyes. The IOP rise was controlled with topical therapy in all eyes except one, which required cyclophotocoagulation. The BCVA was ≥20/40 in 47% of eyes (95% CI: 34%-61%) at baseline and in 58% of eyes at M24 (95% CI: 41%-73%). At M18, the likelihood of achieving a BCVA ≥20/40 was higher in eyes with intact external limiting membrane and ellipsoid zone. Additional dexamethasone implant (DEXi) was injected in 14 eyes (28.57%). The treatment burden of 2.45 ± 1.35 DEXi/year was decreased to 0.57 ± 0.60 DEXi/year after FAc implantation (p=0.001). CONCLUSION: FAc implant improved the BCVA and reduced the CRT in eyes with chronic PCME after vitrectomy. The IOP rise could be anticipated by the previous response to corticosteroids. FAc implant in eyes with chronic PCME also allowed reducing the treatment burden.< Réduire