A New Approach for Diabetic Macular Edema Treatment: review of clinical practice results with 0.19 mg fluocinolone acetonide intravitreal implant including vitrectomized eyes

Injectable biodegradable microchamber array films for long-term delivery of glucocorticoids

Glucocorticoids (GCs) are widely recognized for their potent anti-inflammatory and analgesic effects. Although they can cause an array of side effects when delivered systemically these are generally avoided when delivered locally at disease sites such as the eyes, lungs and joints. Glucocorticoid formulations for local use range from crystals and particles through to non-biodegradable implants. In many formulations burst release means that their effectiveness does not persist for more than a few weeks. Novel delivery methods that achieve prolonged delivery of GCs along with sequential degradation of the polymer vehicle has the potential to enhance the effectiveness of these drugs and achieve better control of disease. In this study we use a soft lithography method to produce polymer microchamber array films (MCAs) containing crystals of GCs. We demonstrate that the rate of glucocorticoid release can be adjusted through the choice of polymer used in the manufacture of films with rapid release observed with PLGA 50/50 over the course of 9 weeks and the longest duration of release observed with PLA films which continued beyond a year. Importantly, these release studies do not show evidence of burst release and all films displayed a significant duration of zero order release kinetics. Observations of film degradation were made through changes in their size, microscopic appearance and liberation of lactic acid from the films during the course of experiments demonstrated the association with GC release kinetics. These flexible films can be rolled into fibers with little change in release kinetics and the rolled MCAs can also be injected in vivo through a syringe needle to a delivery site. We envisage that this study could lead to an innovative approach to achieve prolonged release of GCs from biodegradable formulations at disease sites.

Real-World Evidence of the Long-Term Effectiveness of 0.2 μg/Day Fluocinolone Acetonide Implant in Persistent and Recurrent Diabetic Macular Edema - A Single Center Study

Purpose

To report the long-term functional, anatomical and safety outcomes of 0.2 μg/day fluocinolone acetonide 0.19mg in patients with persistent or recurrent diabetic macular edema (DME).

Methods

Retrospective, observational, single-center study of patients with recurrent or persistent DME. All patients received 0.2 μg/day of fluocinolone acetonide 0.19mg, and data were collected at baseline and months 1, 3, 6, 12, 24 and 36 after implantation. Outcomes measured included best-corrected visual acuity (BCVA), central macular thickness (CMT), intraocular pressure (IOP), and safety outcomes.

Results

A total of 28 eyes from 28 patients were included. The mean age was 66.5 years (95% CI 62.8-70.2) with a mean duration of DME of 8.8 years (95% CI 7.7-10.0). Only two eyes were phakic. Mean follow-up was 25.4 months (95% CI 21.2-29.6). Mean BCVA at baseline was 48.6 ETDRS letters (95% CI 41.3-55.8) and improved as early as month 1 of follow-up with a mean gain in BCVA of 7.8 (95% CI 4.3-11.3) ETDRS letters (p<0.001). Statistically significant improvements in BCVA were also observed at months 6, 12 and 24. At baseline, patients had a mean CMT of 530.5µm (95% CI 463.0-598.0), and a decrease in CMT was observed, starting at the first month of follow-up (mean CMT reduction of -170.5µm, 95% CI -223.8- -117.1; p<0.001). Statistically significant decreases in CMT were also observed at months 6, 12, 24, and 36, with the maximum decrease observed at month 12 (p<0.001). Mean IOP at baseline was 16.4mmHg (95% CI 15.3-17.5) and nine eyes (32.1%) had an IOP ≥21mmHg during follow-up.

Conclusion

Our results support the effectiveness and safety profile of fluocinolone acetonide. Although additional long-term real-world evidence is required, fluocinolone acetonide may represent a safe strategy for daily, low-dose, sustained and localized release to the posterior segment of the eye, providing both functional and anatomical benefits in DME.

Retinal changes after fluocinolone acetonide implant (ILUVIEN®) for DME: SD-OCT imaging assessment using ESASO classification

INTRODUCTION

A detailed understanding of the anatomical and structural changes occurring in the retina following intravitreal fluocinolone acetonide implantation may help improve the management and prognosis of persistent or recurrent diabetic macular edema (DME).

METHODS

Overall, 45 eyes (from 35 patients) with refractory center-involved DME received an intravitreal fluocinolone acetonide implant. They were monitored at baseline and at 6, 12, 24, and 36 months for best-corrected visual acuity (BCVA), central foveal thickness (CFT), and the seven retinal parameters used in the classification of diabetic maculopathy recently developed at the European School for Advanced Studies in Ophthalmology (ESASO).

RESULTS

Within 6 months of implantation, significant improvements were evident in BCVA, CFT, maculopathy stage, and the percentage of eyes with: intraretinal cysts; CFT > 30% above the upper normal value; and disrupted or absent ellipsoid zone (EZ) and/or external limiting membrane (ELM). Significant improvements were still maintained at 36 months post-implantation. At month 36, early treatment with the implant (i.e., after < 6 previous intravitreal injections for DME) trended toward being more effective than later treatment in improving BCVA, CFT, maculopathy stage, and the percentage of eyes with CFT > 30% above the upper normal value. However, statistical significance was not achieved.

CONCLUSION

In persistent or recurrent DME, fluocinolone acetonide implantation can be effective in improving maculopathy stage and reducing the percentage of eyes with: intraretinal cysts; CFT > 30% above the upper normal value; and disrupted or absent EZ and/or ELM. It can also increase BCVA and reduce CFT.

Safety and effectiveness of the fluocinolone acetonide intravitreal implant (ILUVIEN): 3-year results from the European IRISS registry study

BACKGROUND

The ILUVIEN Registry Safety Study was a multicentre, open-label, non-randomised, observational, phase 4 study designed to assess the safety and effectiveness of the fluocinolone acetonide (FAc) implant in all indications in real-world practices in Europe.

METHODS

The study included data collected prospectively and retrospectively. Patients receiving FAc implants between 2013 and 2017 were included and monitored until the last patient reached ≥3 years of follow-up. Mean intraocular pressure (IOP) data over the course of the study, along with IOP events, use of IOP-lowering therapy, mean change in visual acuity (VA) and information on supplemental therapy use were analysed post-FAc implantation.

RESULTS

Six hundred and ninety-five eyes from 556 patients, with a mean±SD follow-up of 1150.5±357.36 days, were treated with a FAc implant. 96.7% of eyes had chronic diabetic macular oedema (cDMO). IOP lowering was achieved in 34.5% of eyes using topical agents and 4.3% by surgery. Seventy-three eyes (64.6% of 113 phakic) required cataract surgery during follow-up. Mean VA increased from a baseline of 52.2 letters to 57.1 letters at month 36, with improvement observed up to month 48. Supplementary therapies were given in 43.7% of eyes. When classified by length of cDMO less than or greater than the median duration those with a shorter history experienced greater VA gains than those with a longer history.

CONCLUSION

This study confirms the favourable, long-term benefit-to-risk profile of the FAc implant in eyes with cDMO, with an additional benefit in patients when this therapy is administered earlier.

Extended real-world experience with the ILUVIEN® (fluocinolone acetonide) implant in the United Kingdom: 3-year results from the Medisoft® audit study

BACKGROUND

This study aimed to assess the long-term effectiveness of the 0.2 μg/day fluocinolone acetonide (FAc) implant over ≥3 years for patients with diabetic macular oedema.

METHODS

A retrospective audit of pseudo-anonymised data from patients with chronic diabetic macular oedema (cDMO) and treated with the FAc implant across 14 UK clinical sites. Safety and clinical effectiveness were measured.

RESULTS

Two-hundred and fifty-six eyes had ≥3 years of follow-up (mean 4.28 years), during which a mean of 1.14 FAc implants were used per eye. Mean best-recorded visual acuity (BRVA) increased from 52.6 to 56.7 letters at month 3 and remained stable thereafter; this trend was also seen in pseudophakic eyes. The proportion of patients attaining a BRVA ≥6/12 increased from 17% at baseline to 27% 1 month after FAc implant and remained stable above 30% from month 12 onwards. Eyes with no prior history of intraocular pressure (IOP)-related events required significantly less treatment-emergent IOP-lowering medication than those with a prior history of IOP events (17.9% vs. 50.0% of eyes; p < 0.001). The incidence of an IOP increase of ≥10 mmHg, use of IOP-lowering medication, laser trabeculoplasty and IOP-lowering surgery was 28.9%, 29.7%, 0.8% and 2.7%, respectively, for the whole cohort. There were significant reductions in mean central foveal thickness and macular volume (p < 0.001).

CONCLUSIONS

The FAc implant was well tolerated, with predictable and manageable IOP-related events while delivering a continuous microdose of corticosteroid to eyes with cDMO, providing prolonged vision preservation and a reduced number of treatments.

Diabetic macular edema treatment guidelines in India: All India Ophthalmological Society Diabetic Retinopathy Task Force and Vitreoretinal Society of India consensus statement

Diabetic macular edema (DME) is a common cause of moderate visual impairment among people with diabetes. Due to the rising number of people with diabetes in India, the absolute numbers of people with DME are significant. There are several treatment options for DME, and the choice of treatment is based on the availability of retinal specialists and infrastructure for the delivery of treatment. A major challenge is the out-of-pocket expenditure incurred by patients as most treatment options are costly. Treatment also varies based on the associated ocular and systemic conditions. The All India Ophthalmology Society (AIOS) and the Vitreo-Retinal Society of India (VRSI) have developed this consensus statement of the AIOS DR task force and VRSI on practice points of DME management in India. The objective is to describe the preferred practice patterns for the management of DME considering the different presentations of DME in different clinical scenarios.

IL-17A Damages the Blood-Retinal Barrier through Activating the Janus Kinase 1 Pathway

Blood-retinal barrier (BRB) dysfunction underlies macular oedema in many sight-threatening conditions, including diabetic macular oedema, neovascular age-related macular degeneration and uveoretinitis. Inflammation plays an important role in BRB dysfunction. This study aimed to understand the role of the inflammatory cytokine IL-17A in BRB dysfunction and the mechanism involved. Human retinal pigment epithelial (RPE) cell line ARPE19 and murine brain endothelial line bEnd.3 were cultured on transwell membranes to model the outer BRB and inner BRB, respectively. IL-17A treatment (3 days in bEnd.3 cells and 6 days in ARPE19 cells) disrupted the distribution of claudin-5 in bEnd.3 cells and ZO-1 in ARPE19 cells, reduced the transepithelial/transendothelial electrical resistance (TEER) and increased permeability to FITC-tracers in vitro. Intravitreal (20 ng/1 μL/eye) or intravenous (20 ng/g) injection of recombinant IL-17A induced retinal albumin leakage within 48 h in C57BL/6J mice. Mechanistically, IL-17A induced Janus kinase 1 (JAK1) phosphorylation in bEnd.3 but not ARPE19 cells. Blocking JAK1 with Tofacitinib prevented IL-17A-mediated claudin-5 dysmorphia in bEnd.3 cells and reduced albumin leakage in IL-17A-treated mice. Our results suggest that IL-17A can damage the BRB through the activating the JAK1 signaling pathway, and targeting this pathway may be a novel approach to treat inflammation-induced macular oedema.

Rho-Kinase Inhibitors for the Treatment of Refractory Diabetic Macular Oedema

Diabetic macular oedema (DMO) is one of the leading causes of vision loss associated with diabetic retinopathy (DR). New insights in managing this condition have changed the paradigm in its treatment, with intravitreal injections of antivascular endothelial growth factor (anti-VEGF) having become the standard therapy for DMO worldwide. However, there is no single standard therapy for all patients DMO refractory to anti-VEGF treatment; thus, further investigation is still needed. The key obstacles in developing suitable therapeutics for refractory DMO lie in its complex pathophysiology; therefore, there is an opportunity for further improvements in the progress and applications of new drugs. Previous studies have indicated that Rho-associated kinase (Rho-kinase/ROCK) is an essential molecule in the pathogenesis of DMO. This is why the Rho/ROCK signalling pathway has been proposed as a possible target for new treatments. The present review focuses on the recent progress on the possible role of ROCK and its therapeutic potential in DMO. A systematic literature search was performed, covering the years 1991 to 2021, using the following keywords: "rho-Associated Kinas-es", "Diabetic Retinopathy", "Macular Edema", "Ripasudil", "Fasudil" and "Netarsudil". Better insight into the pathological role of Rho-kinase/ROCK may lead to the development of new strategies for refractory DMO treatment and prevention.

Recent trends in drug-delivery systems for the treatment of diabetic retinopathy and associated fibrosis

Diabetic retinopathy is a frequent microvascular complication of diabetes and a major cause of visual impairment. In advanced stages, the abnormal neovascularization can lead to fibrosis and subsequent tractional retinal detachment and blindness. The low bioavailability of the drugs at the target site imposed by the anatomic and physiologic barriers within the eye, requires long term treatments with frequent injections that often compromise patient's compliance and increase the risk of developing more complications. In recent years, much effort has been put towards the development of new drug delivery platforms aiming to enhance their permeation, to prolong their retention time at the target site and to provide a sustained release with reduced toxicity and improved efficacy. This review provides an overview of the etiology and pathophysiology of diabetic retinopathy and current treatments. It addresses the specific challenges associated to the different ocular delivery routes and provides a critical review of the most recent developments made in the drug delivery field.

Optical Coherence Tomography Biomarkers: Vitreous Status Influence in Outcomes for Diabetic Macular Edema Therapy with 0.19-mg Fluocinolone Acetonide Implant

BACKGROUND

The 0.19-mg fluocinolone acetonide (FAc) implant (ILUVIEN®; Alimera Sciences Ltd., Hampshire, UK) was approved for the treatment of vision impairment associated with chronic and refractory diabetic macular edema (DME).

OBJECTIVES

To quantitatively assess functional and structural features in nonvitrectomized and vitrectomized DME patients after being treated with an FAc implant.

METHODS

Retrospective review of patients with DME receiving a single intravitreal injection of the FAc implant. The study was designed to analyze the presence of quantitative structural OCT biomarkers at baseline and 12 months after FAc therapy according to vitreous status.

RESULTS

A total of 41 eyes from 30 patients were included in this study. At 12 months after injection, vitrectomized patients had a lower central foveal thickness (p = 0.017) and fewer hyperreflective dots (p = 0.028) compared with nonvitrectomized. Thirty (73%) patients presented a significant functional improvement with 17 (42%) increasing at least 15 ETDRS letters. Overall, 22 (54%) eyes had a complete resolution of DME at the 12-month visit. Patients who needed additional therapy had a higher prevalence of subretinal fluid (42 vs. 3%, p = 0.005) at baseline.

CONCLUSIONS

This study supports the effectiveness of the FAc implant and reports significant changes at 12 months after FAc injection.