Drug targeting to choroidal neovascularization

Subfoveal choroidal neovascularization (CNV) causes significant visual loss , especially in patients with age-related macular degeneration (AMD). Sever al pharmaceutical treatments that use anti-angiogenic agents have been trie d to inhibit the activity of CNV experimentally and clinically. In general, however, systemically administered drugs may reach not only targeted tissu es but also other tissues, resulting in unwanted side effects. Also, to mai ntain therapeutic levels of the drugs in targeted tissues, frequent adminis tration for an extended period of time is required. To solve these problems , drug delivery systems targeted to the CNV are being developed. Anatomic c haracteristics of CNV tissues resemble those of tumor vasculature, exhibiti ng enhanced permeability and retention effect. Drug targeting to CNV may be feasible in the same manner as it is to tumors. In this review, we describ e two approaches of drug targeting to CNV: passive targeting and active tar geting. (C) 2001 Elsevier Science B V All rights reserved.