Hageman factor and kallikrein in pathogenesis of senile cataracts and the pseudoexfoliation syndrome

Abstract

It is thought that dystrophic changes in the human aging anterior eye are due to lipid peroxidation in both the cortical and nuclear structures of the lens under the conditions of ischemia. These changes are often accompanied by only lens opacification (senile cataract-SC) or by formation of amorphous or fibrillar deposits in anterior eye, disturbances of eye hydrodynamics and lens opacification (pseudoexfoliation syndrome-PES). Our results suggest that the main reason of dystrophic changes in the tissues of the aging anterior eye is the disturbance of the haemato-ophthalmic barrier and that the plasma kallikrein-kinin system takes part in this disturbance. Penetration of plasma proteins, such as C-reactive protein, complement components, immunoglobulins and coagulation factors, from plasma into the aqueous humor is responsible for damaging epithelial structures of anterior eye and formation of pseudoexfoliative material. Using ELISA, the C-reactive protein, IgG and IgM antigens have been shown to localize on the surface of the opaque lenses. Presence of these complement binding proteins in the superficial lens structures as well as the high C3a concentration in the aqueous humor substantiates the pathogenic role of complement activation in the lenticular epithelium upon cataract and PES formation.