Vascular plasticity--the role of the angiopoietins in modulating ocular angiogenesis

Most of the blinding diseases, such as diabetic retinopathy, age-related macular degeneration, neovascular glaucoma or trachoma, are related to an aberrant angiogenic response. Common pathological features are ischaemia and increased vascular permeability, in turn leading to neovascularization or atrophy. Recent effort has led to the identification of several factors, such as the angiopoietin-Tie system, which are operative in the control of vasculogenesis and angiogenesis. The aim of this commentary is to summarize briefly the current knowledge about molecular mechanisms involved in the regulation of vascular integrity with special emphasis on the angiopoietins.