Contributor. Gordon K. Klintworth
Hemorrhage can occur either by diapedesis or by flow through ruptured blood vessel walls. Following its onset bleeding may continue because of a hemorrhagic diathesis resulting from an impaired hemostasis, especially if blood coagulation is defective. The most common cause of hemorrhage is trauma, but it can also result from disorders that affect the integrity of the vascular wall, from deficient or defective platelets (as in thrombocytopenia, Bernard-Soulier syndrome, and Glanzmann thrombasthenia), and defects in blood coagulation proteins. The latter include congenital deficiencies (von Willebrand syndrome, afibrinogenemia, hemophilia A, hemophilia B). The synthesis of coagulation proteins by the liver may be defective in Vitamin K deficiency, cirrhosis and other hepatocellular disease [liver disease]. Disorders that affect the integrity of the vascular wall include disorders of connective tissue (Ehlers-Danlos syndrome, Marfan syndrome, Pseudoxanthoma elasticum, Osler-Rendu-Weber syndrome) and some acquired conditions (Cushing syndrome, diabetes mellitus, systemic lupus erythematosus). Ocular hemorrhage is common and can involve specific parts of the eye, such as the conjunctiva [hemorrhage - conjunctiva], cornea [hemorrhage - cornea], anterior chamber [hemorrhage - anterior chamber], retina [hemorrhage - retina], choroid [hemorrhage - choroid], optic nerve [hemorrhage - optic nerve], eyelid [hemorrhage - eyelid] and orbit [hemorrhage - orbit]. A devastating type of ocular hemorrhage is the expulsive hemorrhage [hemorrhage - expulsive].