Kallikrein-kinin activation by altered vitreous pH: New perspectives for treatment and pathogenesis of diabetic macular edema? : Comment on: Gao BB et al. Extracellular carbonic anhydrase mediates hemorrhagic retinal and cerebral vascular permeability through prekallikrein activation. Nat Med. 2007 Feb;13(2):181-8.

Recently, Gao et al. published an experimental study based on the pathophysiology of diabetic macular edema in Nature Medicine (Nat Med. 2007 Feb;13(2):181-8). They found an increased amount of carbonic anhydrase in the vitreous, which causes a pH shift. This activates the kallikrein-kinin system and leads to increased retinal vascular permeability. In this comment the clinical implications of this article are discussed.