Anterior chamber migration of dexametasone intravitreal implant (Ozurdex®)

Abstract

Dear Editor, Ozurdex® (Allergan Inc., Irvine, CA, USA) is an intravitreal implant containing the dexamethasone. It uses NOVADUR® drug delivery technology, in which a biodegradable material is combined with the active drug dexamethasone to form a small rod-shaped implant of 0.46 mm in diameter and 6 mm in length. Inside the eye, the implant is progressively dissolved in the vitreous gel, as it slowly releases dexamethasone (0.7 mg). This biodegradable device is indicated for the treatment of macular edema following branch or central retinal vein occlusions. In large clinical trials, Ozurdex® has also proved effective in the treatment of posterior non-infectious uveitis, and diabetic and macular edema to and pseudophakic macular edema [1, 2]. Herein we report the case of a 68-year-old male diagnosed with macular edema following branch retinal vein occlusion in his left eye. Visual acuity was 0.6 logMAR. The patient had undergone cataract surgery years before, with intraoperative violation of the lens posterior capsula, anterior vitrectomy assisted with triamcinolone and iris-claw intraocular lens implantation. An intravitreous injection of Ozurdex® (Allergan Inc., Irvine, CA, USA) was performed without remarkable complications. Three weeks later, the patient attended our emergency department complaining of blurred vision in his left eye. Slit-lamp examination revealed the presence of diffuse corneal edema, and anterior migration of the implant (Fig. 1). The intraocular pressure measured 18 mmHg. The implant was surgically removed from the anterior chamber 48 hours later. However, corneal edema did not resolve, and the patient finally underwent corneal transplantation. The anterior chamber transit has been previously described for triamcinolone acetonide, resulting in pseudohypopion [3, 4]. Probably due to a similar mechanism, the dexamethasone implant may also migrate into the anterior chamber, with secondary corneal descompensation due to the contact of the implant with the endothelium. This may be more frequent in pseudophakic cases with Nd-YAG capsulotomy, or posterior capsule violation during phacoemulsification. Nevertheless, pseudohypopion after intravitreal triamcinolone injection has been described in both phakic or pseudophakic patients with posterior capsule integrity, it being presupposed then that the zonula is not complete or that the crystals are capable of crossing through it [3, 4]. In this particular case, the lack of anterior hyaloid may facilitate the penetration of Ozurdex into the anterior chamber too. In our opinion, the state of anterior hyaloid can be assessed by slit-lamp examination only. However, ecography could be useful in cases of uncertain anterior hyaloid status. The authors certify that they have not been published or are being considered for publication elsewhere. The authors also transfer property rights (copyright) of this work to Graefe’s Archive for Clinical and Experimental Opthalmology. D. Pardo-Lopez : E. Frances-Munoz :R. Gallego-Pinazo : M. Diaz-Llopis Department of Ophthalmology, University and Polytechnic Hospital La Fe, Valencia, Spain