Intravitreal Dexamethasone Implant as a Sustained Release Drug Delivery Device for the Treatment of Ocular Diseases: A Comprehensive Review of the Literature

Abstract

Drug delivery into the vitreous chamber remains a great challenge in the pharmaceutical industry due to the complex anatomy and physiology of the eye. Intravitreal injection is the mainstream route of drug administration to the posterior segment of the eye. The purpose of this review is to assess the current literature about the widening use of the intravitreal 0.7 mg dexamethasone (Dex) implant, and to provide a comprehensive collection of all the ocular disorders that benefit from Dex administration. Although anti-vascular endothelial growth-factors (VEGFs) have been largely indicated as a first-choice level, the Dex implant represents an important treatment option, especially in selected cases, such as vitrectomized eyes or patients in whom anti-VEGF failed or are contraindicated. In this article, the safety profile as well as the list of the possible complications related to intravitreal Dex injection are also discussed.

Intravitreal Dexamethasone Implant in Patients Who Did Not Complete Anti-VEGF Loading Dose During the COVID-19 Pandemic: a Retrospective Observational Study

“…COVID-19 has posed a global public health threat due to the severity of its contagion and associated morbidity and mortality [ 16 , 17 ]. In fact, the volume of outpatient and surgical procedures has significantly decreased during the pandemic [ 12 ]. In most ophthalmic centers, provision of care was restricted to urgent or emergency cases [ 21 ].…”

“…With the coronavirus disease 2019 (COVID-19) outbreak over the last year, the strategies adopted by different governments to reduce the risk of infection spread have dramatically disrupted the provision of health care, resulting in deferral of routine ophthalmic procedures [ 12 , 13 ]. As a result of the risk of irreversible visual loss, treatment planning and prioritization during the pandemic has become more critical than ever in order to achieve and maintain optimal clinical outcomes in patients with DME [ 14 , 15 ].…”

Evolving Treatment Paradigm in the Management of Diabetic Macular Edema in the Era of COVID-19

“…Anti-vascular endothelial growth factor (VEGF) injections represent generally a first-line therapy for several retinal disorders including DME ( Heier et al, 2012 ; Reibaldi et al, 2014 ; Schmidt-Erfurth et al, 2017 ; Plyukhova et al, 2020 ), but monthly injections are needed at least during the loading dose ( Schmidt-Erfurth et al, 2017 ). Of note, intravitreal dexamethasone (DEX) implant 0.7 mg (Ozurdex®, Allergan, Inc. Irvine, CA, United States) is considered a valid alternative for both refractory to anti-VEGF treatment eyes and treatment naïve ones ( Iglicki et al, 2019 ; Iovino et al, 2020b ). Intravitreal DEX implant releases active ingredients within the vitreous chamber over a 3–6 months period, and its efficacy and safety in various retinal diseases have been proved in clinical trials and real-life studies ( Maturi et al, 2016 ; Rajesh et al, 2020 ).…”

“…Several authors also reported significant anatomical and functional effects of DEX implant in vitrectomized eyes in different conditions ( Boyer et al, 2011 ; Reibaldi et al, 2012 ; Iovino et al, 2019 ). Corticosteroids have multiple levels of action, modifying tight junction integrity, inhibiting different molecules involved in vascular permeability and inflammation processes including interleukin-6, stroma-derived factor-1, Intercellular adhesion molecule-1, as well as VEGF ( Iovino et al, 2020b ).…”

“…Cataract progression and intraocular pressure rise are the most common side effects, but often rather easily manageable ( Iovino et al, 2020b ; Rajesh et al, 2020 ). Additionally, several optical coherence tomography (OCT) biomarkers were identified as functional outcome predictors in DME eyes treated with DEX implant including the presence of submacular fluid, absence of hyperreflective intraretinal foci and integrity of the ellipsoid zone ( Zur et al, 2018 ).…”