Retinal thickness fluctuations in patients receiving fluocinolone acetonide implant for diabetic macular edema

Long-Term Control of Retinal Thickness Variability and Vision Following the 0.19 mg Fluocinolone Acetonide Implant

Purpose: To assess the impact of retinal thickness variability (RTV) control on visual and treatment burden outcomes in patients with diabetic macular edema (DME) who received the 0.19 mg fluocinolone acetonide (FAc) intravitreal implant (Iluvien, Alimera Sciences). Methods: This post hoc analysis examined the outcomes of a 3-year, phase 4, nonrandomized, open-label observational study. Retinal thickness was measured as central subfield thickness (CST). RTV was quantified by CST area under the curve (CST-AUC), retinal thickness amplitude (RTA), and retinal thickness standard deviation (RTSD). Visual outcomes were measured as best-corrected visual acuity (BCVA), and treatment burden was measured as the number of yearly supplemental DME treatments. Results: The percentage of eyes with a CST ≤300 µm fluctuated throughout the study but was significantly increased relative to baseline at 36 months (baseline: 32.9% vs 36 months: 46.8%; P < .05). FAc significantly reduced RTV in all measures more than 36 months (P < .0001). When divided into quartiles, eyes with the best RTV control post FAc had the greatest BCVA gains and improved disease control (ie, reduced need for supplemental therapy). The last-observed BCVA letter score exhibited linear correlations with CST-AUC (R2 = -0.100), RTA (R2 = -0.125), and RTSD (R2 = -0.162). A multivariate linear regression with baseline BCVA as a covariate displayed improved correlations with the last-observed BCVA, CST-AUC (R2 = -0.448), RTA (R2 = -0.432), and RTSD (R2 = -0.436). Conclusions: The sustained corticosteroid release of the 0.19 mg FAc implant reduced RTV in patients with DME, which directly correlated with significantly improved vision and a reduced supplemental treatment burden.

The 0.19-mg Fluocinolone Acetonide Implant for the Treatment of Diabetic Macular Edema: An Expert Consensus

BACKGROUND AND OBJECTIVE

To better understand the level of agreement among retina specialists on the role of inflammation in diabetic retinopathy (DR) and diabetic macular edema (DME), and the use of 0.19-mg fluocinolone acetonide (FAc) implant in DME treatment, a consensus survey was drafted and disseminated to retina specialists across the United States.

MATERIALS AND METHODS

Using the modified Delphi method, a list of 12 consensus statements were generated by the coauthors based on short-answer responses to an initial survey. In total, 56 retina specialists completed the entire consensus survey. Except for two multiple-choice questions, there were 10 consensus statements that used a modified Likert scale to indicate their level of agreement to the statement: Agree = 3, Mostly Agree = 2, Mostly Disagree = 1, Disagree = 0. Percentage agreement and 95% confidence intervals (CIs) were calculated, and a consensus threshold was set at > 80% agreement for each statement.

RESULTS

Seven of 10 consensus statements using the modified Likert scale reached consensus, including those on the role of inflammation in pathophysiology of DR/DME, injection burden and patient adherence, and efficacy and safety of the FAc implant. The remaining three statements displayed high agreement with average scores > 80%, but the 95% CIs were below threshold. These included the impact of the FAc implant on DR progression, FAc as baseline therapy for DME, and the effectiveness of the steroid challenge to mitigate intraocular pressure risk after FAc use. Two multiple-choice questions focused on clinical situations in which corticosteroids would be used as baseline therapy for DME (pseudophakic eye [73%], recent stroke/myocardial infarction [66%], and pregnancy/breastfeeding [66%]) and which delivery route satisfies the steroid challenge for the FAc implant (intravitreal [100%], sub-tenon/periocular [73%], and topical [57%]).

CONCLUSIONS

Physicians highly agreed on the role of inflammation in pathophysiology of DR/DME, injection burden and patient adherence, and efficacy and safety of the FAc implant. However, full consensus was not found on the impact of the FAc implant on DR progression, FAc as baseline therapy for DME, and the effectiveness of the steroid challenge to mitigate intraocular pressure risk after FAc use. [Ophthalmic Surg Lasers Imaging Retina. 2023;54(3):166-173.].

Management of Patients with Diabetic Macular Edema Switched from Dexamethasone Intravitreal Implant to Fluocinolone Acetonide Intravitreal Implant

To assess anatomical and functional outcomes after switching from dexamethasone implant (DEXi) to fluocinolone acetonide implant (FAci) in 113 diabetic macular edema eyes, a multicentric retrospective observational study was conducted. Seventy-five eyes (73.5%) were switched 1−8 weeks after their last DEXi. The mean best-corrected visual acuity improved to 59.8 letters at month 4 and remained stable during the follow-up. The mean central macular thickness (CMT) significantly decreased during the follow-up, with a minimum of 320.9 μm at month 3. The baseline CMT was higher in eyes that received the last DEXi >8 weeks versus <8 weeks before the first FAci (p < 0.021). After FAci injection, additional treatments were needed in 37 (32.7%) eyes. A longer diabetes duration (p = 0.009), a longer time between the last DEXi and the first FAci (p = 0.035), and a high baseline CMT (p = 0.003) were risk factors for additional treatments. The mean intraocular pressure was <19 mmHg at all timepoints, with no difference between eyes receiving the last DEXi ≤8 weeks or >8 weeks before the switch. Switching from DEXi to FAci in DME is effective and safe. A short time between the last DEXi and the first FAci reduced CMT fluctuations and the need for early additional treatments.

Optical Coherence Tomography Biomarkers of Inflammation in Diabetic Macular Edema Treated by Fluocinolone Acetonide Intravitreal Drug-Delivery System Implant

Introduction

The fluocinolone acetonide (FAc) intravitreal drug-delivery system implant is a recent, second-line, intravitreal drug for the management of diabetic macular edema (DME). FAc acts against DME with a major anti-inflammatory effect. Despite the already proved efficacy, a number of patients still show persistent DME and require anti-VEGF retreatment. The main aim of the present study was to assess the relationship between quantitative biomarkers of inflammation and both DME recovery and the need for additional anti-VEGF in eyes treated by FAc implant.

Methods

The study was designed as prospective and interventional with 1 year of follow-up. We analyzed structural optical coherence tomography (OCT) quantitative biomarkers of inflammation, namely choroidal hyperreflective foci (HF) and the choroidal vascularity index (CVI), and we assessed the relationship with other clinically relevant biomarkers and the outcome achieved after 1 year. Moreover, we stratified DME eyes in good and poor responders to FAc implant to highlight clinically relevant differences.

Results

Our study included 50 eyes (50 patients) treated by FAc implant. We found significant best-corrected visual acuity (BCVA) and central macular thickness (CMT) improvements after 1 year. Good responders started with worse visual acuity and higher CMT than poor responders, but gained letters significantly at the end of the follow-up, whereas poor responders showed stable BCVA values. Good responders were characterized by significantly higher choroidal HF and lower CVI than poor responders. Poor responders required significantly higher additional anti-VEGF treatments.

Conclusions

Quantitative structural OCT biomarkers of inflammation allowed distinguishing different inflammatory profiles of DME. The inflammatory component helped to categorize DME eyes in good and poor responders to FAc implant.