Dexamethasone Intravitreal Implant for Treatment of Macular Edema After Plaque Radiotherapy of Uveal Melanoma

Plaque radiotherapy is a commonly used method for treatment of small and medium-sized uveal melanomas. Macular edema is one of the most common causes of visual loss after plaque radiotherapy and has been reported in up to 70% of patients with posterior uveal melanoma. Different methods have been proposed for treatment of post-radiation macular edema and include periocular steroid, intravitreal steroid, intravitreal vascular endothelial growth factor (VEGF) inhibitors, photodynamic therapy, and macular laser photocoagulation. Injection of intravitreal triamcinolone (a form of steroid) has been found to be useful for treatment of different forms of macular edema but is associated with considerable rates of increased intraocular pressure (glaucoma). Dexamethasone is more potent than triamcinolone and can be safely injected directly into the vitreous cavity (intravitreal injection) but unfortunately its use in the form of intravitreal injection is not practical due to the short half-life of intraocular dexamethasone (about 3 hours). Within the past several years, tiny drug delivery systems have been developed that allow sustained release of minute amounts of steroid into the back part (vitreous cavity) of the eye, when they are implanted into the vitreous cavity. Ozurdex is a biodegradable dexamethasone intravitreal implant that has been shown to be well-tolerated and effective for up to 6 months in reducing vision loss and improving visual outcome in eyes with different types of macular edema including those secondary to diabetic retinopathy and retinal vein occlusion. In this study the investigators would like to evaluate the safety and effectiveness of Ozurdex (dexamethasone intravitreal implant) for treatment of macular edema developing after plaque radiotherapy of uveal melanoma.