Comment on: "Use of the Fluocinolone Acetonide Intravitreal Implant for the Treatment of Noninfectious Posterior Uveitis: 3-Year Results of a Randomized Clinical Trial in a Predominantly Asian Population".

Abstract

I read “Use of the fluocinolone acetonide intravitreal implant for the treatment of noninfectious posterior uveitis (NIPU): 3-year results of a randomized clinical trial in a predominantly Asian population” (December 2014) [1]. This article is certainly of interest, especially regarding the effectiveness of 0.59 and 2.1 mg doses of fluocinolone acetonide (FAc) intravitreal implant for the treatment of NIPU in a predominantly Asian patient population. However, I would like to make sure that your readership does not confuse the FAc intravitreal implant reported by Sangwanet al. (i.e., Retisert; contains 0.59 mg of FAc) with the FAc implant (ILUVIEN®; contains 190 μg of FAc) licenced in Europe for the indication ‘… for the treatment of vision impairment associated with chronic diabetic macular edema (DMO), considered insufficiently responsive to available therapies [2]’. This letter highlights the key differences between Retisert and ILUVIEN. These products are licenced by different manufacturers. Retisert is manufactured by Bausch & Lomb (Rochester, NY, USA) and ILUVIEN is manufactured by Alimera Sciences (based in Atlanta, Georgia, USA and Aldershot, UK). These products contain and deliver different amounts of FAc. Retisert delivers 0.59 mg of FAc with an initial rate of 0.6 mg of FAc per day, which decreases over the 1st month to a steady rate of 0.3–0.4 μg FAc per day [3]. ILUVIEN contains a total of 190 μg of FAc with an average daily release of 0.2 μg of FAc per day [2, 4]. These products release FAc for different amounts of time. Retisert releases 0.3–0.4 μg FAc per day for between 30 [3, 4] and 36 months [1]. In contrast, ILUVIEN releases 0.2 μg FAc per day for up to 36 months [4]. These products are administered differently. Retisert is surgically implanted into the posterior segment of the affected eye through a pars plana incision. ILUVIEN is an intravitreal implant that is inserted using a 25-gage needle into the vitreous cavity in the posterior eye with the optimal placement being inferior to the optic disc and posterior to the equator [2]. These products have different indications. In Europe, Retisert is not licensed whereas ILUVIEN is licensed and indicated for “… the treatment of vision impairment associated with chronic diabetic macular oedema, considered insufficiently responsive to available therapies.” [2]. In the USA, Retisert is indicated for “…the treatment of chronic noninfectious uveitis affecting the posterior segment of the eye” [3] and not for DMO. The indication for ILUVIEN in the USA is for “…or the treatment of diabetic macular edema in patients who have been previously treated with a course of corticosteroids and did not have a clinically significant rise in intraocular pressure” [5]. I would like to highlight that ILUVIEN was designed to improve on the performance of Retisert to deliver the lowest dose of corticosteroid, currently under investigation, to the retina [6]. Furthermore, I would like to point the reader in the direction of Kane et al. [6] which explains the development history and characteristics of Retisert and ILUVIEN. The paper by Campochiaro et al. [4] is also very helpful as it compares the aqueous levels of FAc after the administration of Retisert or ILUVIEN. John Hall, MD Senior Vice President, Medical Director Europe