Macugen [TM] (OSI-Eyetech, Inc. and Pfizer, Inc.), also known as pegaptanib, is a drug which has the ability to block one of the isoforms of VEGF called VEGF(165), leaving the other types of VEGF unaffected [8]. It inhibits the amount of leakage of fluid through blood vessel walls. It has been demonstrated that VEGF(165) alone mediates abnormal new blood vessel development in the eye, and its inactivation by Macugen [TM] inhibits the new vessel development observed in patients with neovascular AMD [8] without affecting normal blood vessel development, which is supported by the VEGF(121) isoform. In addition, animal model studies have shown that injection of Macugen [TM] into the fluid at the back of the eye ("intravitreal injection") can inhibit or even show signs of reversing the typical damage to the blood vessels that occurs in diabetes. [9] These findings suggest that that intravitreal Macugen [TM] could provide a safe and effective treatment against both the development of abnormal new blood vessels in the eye and diabetes-induced damage to the blood vessels of the retina. [6] They formed the basis for randomized controlled trials examining the efficacy of Macugen [TM] as a therapy for AMD and DME. [8]