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

The Treatment of Diabetic Retinal Edema with Intravitreal Steroids: How and When

Diabetic macular edema (DME) is a common complication of diabetes mellitus and a leading cause of visual impairment worldwide. It is defined as the diabetes-related accumulation of fluid, proteins, and lipids, with retinal thickening, within the macular area. DME affects a significant proportion of individuals with diabetes, with the prevalence increasing with disease duration and severity. It is estimated that approximately 25-30% of diabetic patients will develop DME during their lifetime. Poor glycemic control, hypertension, hyperlipidemia, diabetes duration, and genetic predisposition are recognized as risk factors for the development and progression of DME. Although the exact pathophysiology is still not completely understood, it has been demonstrated that chronic hyperglycemia triggers a cascade of biochemical processes, including increased oxidative stress, inflammation, activation of vascular endothelial growth factor (VEGF), cellular dysfunction, and apoptosis, with breakdown of the blood-retinal barriers and fluid accumulation within the macular area. Early diagnosis and appropriate management of DME are crucial for improving visual outcomes. Although the control of systemic risk factors still remains the most important strategy in DME treatment, intravitreal pharmacotherapy with anti-VEGF molecules or steroids is currently considered the first-line approach in DME patients, whereas macular laser photocoagulation and pars plana vitrectomy may be useful in selected cases. Available intravitreal steroids, including triamcinolone acetonide injections and dexamethasone and fluocinolone acetonide implants, exert their therapeutic effect by reducing inflammation, inhibiting VEGF expression, stabilizing the blood-retinal barrier and thus reducing vascular permeability. They have been demonstrated to be effective in reducing macular edema and improving visual outcomes in DME patients but are associated with a high risk of intraocular pressure elevation and cataract development, so their use requires an accurate patient selection. This manuscript aims to provide a comprehensive overview of the pathology, epidemiology, risk factors, physiopathology, clinical features, treatment mechanisms of actions, treatment options, prognosis, and ongoing clinical studies related to the treatment of DME, with particular consideration of intravitreal steroids therapy.

Safety and Efficacy of Dexamethasone Intravitreal Implant Given Either First-Line or Second-Line in Diabetic Macular Edema

Diabetic macular edema (DME) is a common sight-threatening complication of diabetic retinopathy (DR) and the leading cause of severe visual impairment among the working-age population. Several therapeutic options are available for the management of DME, including intravitreal corticosteroids. They have been traditionally used as second-line treatment, due to the risk of intraocular pressure increase and cataract-related adverse events. However, attention has recently been focused on the primary or early use of intravitreal corticosteroids, due to growing evidence of the crucial role of inflammation in the pathogenesis of DME. Furthermore, intravitreal steroid implants offer the additional advantage of a longer duration of action compared to anti-vascular endothelial growth factor agents (anti-VEGF). This review aims to summarize the available evidence on the efficacy and safety profile of dexamethasone (DEX) intravitreal implant, with a specific focus on clinical scenarios in which it might be considered or even preferred as first-line treatment option by adequate selection of patients, considering both advantages and possible adverse events. Patients with contraindications to anti-VEGF, DME with high inflammatory OCT biomarkers, pseudophakic patients and phakic patients' candidates to cataract surgery as well as vitrectomized eyes may all benefit from first-line DEX implant. Additionally, DME not responders to anti-VEGF should be considered for a switch to DEX implant and a combination therapy of DEX implant and anti-VEGF could be a valid option in severe and persistent DME.

Fluocinolone Acetonide Implant Injected 1 Month after Dexamethasone Implant for Diabetic Macular Oedema: the ILUVI1MOIS Study

INTRODUCTION

The aim of this study was to assess the efficacy and safety of fluocinolone acetonide implant (FAci) injected 1 month after the last dexamethasone intravitreal implant (DEXi) in chronic diabetic macular oedema (DME) patients.

METHODS

Retrospective multicentric study conducted in pseudophakic patients with chronic DME frequently treated with dexamethasone intravitreal implant (DEXi; time to DME recurrence ≤ 6 months), receiving FAci 1 month after the last DEXi, with at least a 6-month follow-up. Best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography, intraocular pressure (IOP) and additional treatments were assessed on the day of FAci injection (M0), 1 (M1) and 3 months (M3) later and then every 3 months.

RESULTS

A total of 41 eyes from 34 patients were included. At M0, patients' mean age was 68.7 ± 9.8 years, the mean DME duration was 63.9 ± 22.9 months, the mean interval between two DEXi was 14.2 ± 3.3 weeks. M12 data were available for 71% of patients. At baseline, the mean BCVA, CMT and IOP were 63.2 ± 16.6 letters, 299.4 ± 103.3 µm, and 16.2 ± 4.5 mmHg, respectively, and remained stable during the follow-up. At M12, 14% of patients required additional intravitreal treatments.

CONCLUSION

In pseudophakic patients with chronic DME showing good response to DEXi but requiring repeated injections every < 6 months, switching to FAci 1 month after the last DEXi was effective and safe. Further prospective randomized controlled studies are needed to confirm these findings, and to determine the best interval between the last DEXi and the first FAci.

Ocular hypertension and intravitreal steroids injections, update in 2023. French guidelines of the French glaucoma society and the French ophthalmology society

These guidelines are a consensus of French glaucoma and retina experts on the management of ocular hypertension (OHT) observed in a third of the cases after corticosteroid implant intravitreal injections. They update the first guidelines published in 2017. Two implants are marketed in France: the dexamethasone implant (DEXi) and the fluocinolone acetonide implant (FAci). It is essential to assess the pressure status before injecting a patient with a corticosteroid implant. A molecule-specific monitoring of the intraocular pressure is needed throughout the follow-up and at the time of reinjections. Real-life studies have allowed optimizing the management algorithm by significantly increasing the safety of these implants. Corticosteroid testing with DEXi should be performed before switching to FAci to optimize pressure tolerance of FAci. Beyond topical hypotensive treatments, selective laser trabeculoplasty may be considered in the therapeutic arsenal for the management of steroid-induced OHT and subsequent injections.

[Intraocular pressure elevation and intravitreal steroid implant injection: State of the art in 2023. Recommendations of the French Glaucoma Society and French Ophthalmology Society [French version]]

These are the recommendations of French glaucoma and retina experts on the management of ocular hypertension (OHT) observed in 1/3 of cases after intravitreal steroid implant injections. They are an update to the recommendations first published in 2017. There are two implants on the French market: the dexamethasone (DEXi) and fluocinolone acetonide (FAci) implants. It is important to know the pressure status before injecting a patient with a steroid implant. Monitoring of the IOP adapted to the specific drug is necessary throughout follow-up and reinjections. Real-life studies have made it possible to optimize the management algorithm by significantly increasing the safety of use of these implants. A corticosteroid test with DEXi is necessary before switching to FAci to optimize the pressure tolerance of the latter. In addition to topical glaucoma medications, SLT laser can be considered in the therapeutic arsenal for the management of steroid-induced OHT and future injections.

Intravitreal Injection Planning during COVID-19 Pandemic: A Retrospective Study of Two Tertiary University Centers in Italy

The COVID-19 pandemic has hampered the optimum management of retinal diseases. This study examined the impact of the pandemic on the intravitreal-injection practice in two academic centers in Italy along with the related medico-legal implications. A retrospective analysis of electronic medical records from 16 March 2020 to 14 March 2021 at the ophthalmological departments of University of Cagliari (SGD) and University Magna Græcia of Catanzaro (UMG) was conducted. The data collected between 16 March 2020 and 14 June 2020 (lockdown), 15 June 2020 and 13 September 2020 (unlock), and 14 September 2020 and 14 March 2021 (second wave) were compared with those of the same period of the previous year. Weekly data on the administered drug and the number and type of treated disease were collected and analyzed. During the lockdown, a drop of 59% at SGD (p < 0.00001) and 77% at UMG (p < 0.00001) in intravitreal injections was found. In the first year of the pandemic, the reduction in injections was approximately of 27% (p < 0.0008) and 38% (p < 0.0001) at SGD and UMG, respectively. The COVID-19-related containment measures and the health resources redistribution have led to a delay in the treatment of chronic diseases of the retina, prioritizing the undeferrable ones. The lack of management guidelines has conceived relevant ethical and medico-legal issues that need to be considered in future measures planning.