Clinical trials on corticosteroids for diabetic macular edema

Abstract

Diabetic macular edema (DME) is a common cause of visual impairment in diabetic patients. It is caused by an increase in the permeability of the perifoveal capillaries and a disruption of the blood retinal-barrier. The pathogenesis of DME is multifactorial. Several therapeutic modalities have been proposed for the treatment of DME. Corticosteroid treatments have emerged as an alternative therapy for persistent DME or refractory to conventional laser photocoagulation and other modalities, due to anti-inflammatory, anti-vascular endothelial growth factor and anti-proliferative effects. Many studies have demonstrated the beneficial therapeutic effect of corticosteroids with improvement to both retinal thickness and visual acuity in short-term on the treatment of DME. Peribulbar and intravitreal injections have been used to deliver steroids for DME with frequent injections due to the chronic and recurrent nature of the disease. Steroid-related side effects include elevated intraocular pressure, cataract, and injection related complications such as endophthalmitis, vitreous hemorrhage, and retinal detachment particularly with intravitreal steroid injections. In order to reduce the risks, complications and frequent dosing of intravitreal steroids, intravitreal implants have been developed recently to provide sustained release of corticosteroids and reduce repeated intravitreal injections for the management of DME.

Keywords: Corticosteroids; Diabetic macular edema; Intravitreal steroid sustained-release implants; Intravitreal triamcinolone acetonide injection; Peribulbar steroid injections; Subtenon’s steroid Injections.

Figure 1

Intravitreal triamcinolone acetonide injection. A: External aspect demonstrating intravitreal triamcinolone acetonide (IVTA) injection through the inferior pars plana in sterile conditions; B: Vitreous cavity aspect demonstrating IVTA injection with inferior deposition of triamcinolone acetonide crystals over the retinal surface on a patient with diabetic macular edema refractory to laser photocoagulation.

Figure 2

Diabetic macular edema before and after intravitreal triamcinolone acetonide injection.

Figure 3

Ozurdex biodegradable dexamethasone injectable intravitreal implant in a patient with non-proliferative diabetic retinopathy, diabetic macular edema, and supero-temporal branch retinal vein occlusion.