Effectiveness of the Dexamethasone Intravitreal Implant for Treatment of Patients with Diabetic Macular Oedema

Abstract

Diabetic macular oedema (DMO) is a leading cause of vision loss in the working-age population worldwide. Corticosteroid drugs have been demonstrated to inhibit the expression of both the vascular endothelial growth factor (VEGF) gene and other anti-inflammatory mediators, such as prostaglandins. Triamcinolone, fluocinolone and dexamethasone are the main steroids that have been studied for the treatment of macular oedema. Over the last few years, several studies have suggested an important role for dexamethasone in the management of DMO. The dexamethasone intravitreal implant (DEX implant) (Ozurdex ® ; Allergan, Inc., Irvine, CA) is a novel approach approved by the US Food and Drug Administration (FDA) and by the EU for the intravitreal treatment of macular oedema after branch or central retinal vein occlusion, and for the treatment of non-infectious uveitis affecting the posterior segment of the eye. We reviewed manuscripts that had investigated the pharmacokinetics, efficacy and safety of the DEX implant regarding DMO treatment. KeywordsRefractory diabetic macular oedema, pathogenesis, inflammatory mediators, corticosteroids, dexamethasone intravitreal implant, implantable drug delivery system. 4 On the basis of the data from all 35 studies on more than 20,000 participants with diabetes, they estimated that among individuals with diabetes, the overall prevalence of any DR was 34.6 %, PDR was 7.0 %, DMO was 6.8 % and VTDR was 10.2 %. DR is a highly specific vascular complication of both type 1 and 2 diabetes, with prevalence strongly related to the duration of diabetes.5 In addition to the duration of diabetes, factors that increase the risk of, or are associated with, retinopathy include chronic hyperglycaemia, 6 nephropathy 7 and hypertension.8 Intensive diabetes management with the goal of achieving near-normoglycemia has been shown in large prospective randomised studies to prevent and/or delay the onset and progression of DR.9-11 Lowering blood pressure has been shown to decrease the progression of retinopathy. 12DMO is a frequent complication of DR and the most common cause of vision loss in patients with diabetes. Left untreated, up to 33 % of patients with DMO will experience moderate vision loss. 13 Laser photocoagulation has been considered, for a long time, as the main treatment option for DMO, based on the results of the Early Treatment Diabetic Retinopathy Study (ETDRS) clinical trial.14 Focal laser treatment reduced the risk of moderate visual loss in patients with DMO by 50 %. 15In more recent studies that involved only patients with DMO-associated vision loss, repeated applications of focal/grid laser photocoagulation treatment resulted in at least a 10-letter improvement in visual acuity in 28-32 % of patients, but 13-19 % of patients lost at least 10 letters in visual acuity. [16][17] In DMO, vascular leakage from dilated hyperpermeable capillaries and microaneurysms leads to accumulation of extracellular fluid in the macula. Inflammation has a key role in the pathogenesis and maintenan...

Guidelines for the Management of Center-Involving Diabetic Macular Edema: Treatment Options and Patient Monitorization

“…These have been found useful, especially in treating inflammation and ME in difficult-to-treat vitrectomized eyes, showing vascular leakage and best corrected visual acuity (BCVA) improvement. 29 , 30 …”

Vitreous inflammatory and angiogenic factors on patients with proliferative diabetic retinopathy or diabetic macular edema: the role of Lipocalin2

“…Yet, 30% of DME patients show suboptimal response with anti-VEGF therapy [ 11 ]. In clinical practice, the inflammatory component of DME can be addressed with steroids, such as dexamethasone implants [ 12 – 14 ]. Regarding PDR patients, recent studies have presented very favorable results with anti-VEGF agents (Protocol S, Clarity Study) [ 15 , 16 ].…”

Intraocular Pressure Changes Following the Administration of Intravitreal Dexamethasone Implant: A Mini -Review

“…Intravitreal Dexamethasone Implant (IDI) (Ozurdex®, Allergan, Inc. Irvine, CA) is approved by the US Food and Drug Administration (FDA) for the treatment of macular edema (ME) secondary to diabetes mellitus (DM), non-infectious uveitis (NIU), and branch or central retinal vein occlusion (RVO) [1] . Although off-label, clinical efficacy of the implant in various other disease entities characterized with ME such as post-surgical ME including Irvine-Gass syndrome, Coats disease and retinitis pigmentosa has also been shown by many researchers [2][3][4][5][6] .…”