Clinical Application of Drug Delivery Systems for Treating AMD

Due to transparent ocular media, it is relatively easy to observe intraocular tissues such as the vitreous and retina without invasion, and various administration approaches including intravitreal and subretinal injection, or implantation can be applicable. Since the eye-ball is a closed organ, novel therapeutic molecules such as an antisense oligonucleotide for cytomegalovirus retinitis (Fomivirsen; Vitraven®, Isis Pharmaceuticals, Inc., Carlsbad, CA U.S. and Novartis, Basel, Switzerland), an aptamer (e.g. Pegaptanib sodium; Macugen®, Pfizer, Inc., New York, NY, U.S.) or a small interfering RNA for neovascular (wet) agerelated macular degeneration (AMD), have been investigated in human eyes before their applications for systemic diseases. In addition, many injectable or implantable drug delivery systems for chronic vitreoretinal diseases including AMD, diabetic macular edema, retinal vein occlusion, uveitis, and retinitis pigmentosa (RP), using polymer technology and/or mechanical engineering, have been developing (Figure 1).