Ophthotech Corporation is a United States-based biopharmaceutical company. The Company is engaged in developing and commercializing therapies for the treatment of diseases of the eye and focuses on developing therapeutics for age-related macular degeneration (AMD). Its product pipeline includes Fovista anti-platelet derived growth factor (PDGF) therapy, which is in Phase III clinical trials for use in combination with anti-VEGF drugs to disrupt the formation of abnormal new blood vessels in wet AMD. It prevents PDGF from binding to its natural receptor on pericytes, thus causing pericytes to be stripped from newly formed abnormal blood vessels.Its second product candidate, Zimura, an inhibitor of complement factor C5, is developed for the treatment of geographic atrophy (a form of dry AMD) and, in combination with anti-VEGF therapy and Fovista, for the treatment of wet AMD. Both Fovista and Zimura are aptamers, single strands of nucleic acid that binds with affinity to targets.