[Pathogenesis of retinal vein occlusions]

Retinal vein occlusion (RVO) is a multifactorial disease and its pathogenesis is still not fully understood. Mechanical, hemodynamic, rheological, coagulation, biochemical, and immunological factors are involved. Two currently prevalent theories of RVO pathogenesis are the mechanical theory and the "coagulopathic" theory. The latter implies an imbalance between thrombogenic factors and antithrombogenic protection. According to some authors, endothelial dysfunction plays a large part in thrombosis development, neoangiogenesis, vascular remodeling, intravascular activation of platelets and leucocytes. In recent studies increasing emphasis is being placed on investigation of immune-mediated mechanisms of vein occlusions. RVO can also be associated with combined hypoxic and free radical tissue damage.