The role of abnormalities in the anticoagulant and fibrinolytic systems in retinal vascular occlusions

Iron Deficiency Anemia with Marked Thrombocytosis Complicated by Central Retinal Vein Occlusion

“…It has been reported that blood abnormalities, including iron deficiency anemia, are involved in the disturbance of retinochoroidal circulation in many young patients who usually do not have arteriosclerosis (6-9). The mechanisms of iron deficiency anemiainduced disturbance of retinochoroidal circulation remain unclear; however, formation of a thrombus due to hypoxiainduced injury of angioendothelial cells and deregulation of the coagulation-fibrinolysis system as well as thrombocytosis may be involved in the development of such ophthalmic disorders (5,7). In fact, patients with iron deficiency anemia who have no thrombocytosis can also be complicated by disturbance of retinochoroidal circulation.…”

“…A disturbance of retinochoroidal circulation can accompany some blood abnormalities, including iron deficiency anemia (5). The disturbance causes various ophthalmic disorders, including retinal vein occlusion and retinal artery occlusion (6)(7)(8)(9).…”

“…The disturbance causes various ophthalmic disorders, including retinal vein occlusion and retinal artery occlusion (6)(7)(8)(9). It has been speculated that the disturbance of retinochoroidal circulation is caused by formation of thrombosis due to hypoxia-induced injury of angioendothelial cells, deregulation of the coagulation/fibrinolytic system and thrombocytosis in iron deficiency anemia (5,7).…”

Abnormalities in haemorheological factors and lipoprotein (a) in retinal vascular occlusion: Implications for increased vascular risk

“…However, there are three basic pathological processes: degenerative ch anges of the vessel wall; abnormal haematological factors; and an abnormal perivascular status, such as an adjacent sclerotic vessels sharing a common adventitia. 1 The exact aetiology of retinal vein occlusion is unclear. Histological studies suggests two different principal factors in the mechanism of occlusion: firstly, primary endothelial degeneration and swelling with secondary intramural formation of thrombus and, secondly, extreme phlebosclerosis' with secondary endothelial degeneration.14,15 By contrast, in patients with retinal artery occlusion, thromboembolism is considered to be commonest underlying cause, although the source is often undetected (in two-thirds), suggesting that an intrinsic prothrombotic or hypercoagulable state may exist; amongst those with thromboembolism, carotid artery disease can be present in 27%, whilst a cardiac origin is unusual (2%).…”

Protein C activation in NIDDM patients

“…It is believed that enhanced pro-coagulant activity is linked to the excessive cardiovascular morbidity and mortality among diabetic patients which have not been fully explained by major risk factors such as arterial hypertension, cigarette smoking and hypercholesterolaemia. Perturbance of haemostasis has also been implicated in the development of complications such as nephropathy and retinopathy and in the acceleration of atherogenesis observed in diabetic patients [1,2]. Diabetologia (1996Diabetologia ( ) 39: 1455Diabetologia ( -1461 Protein C activation in NIDDM patients Summary Enhanced activation of the clotting system has been recently implicated in the pathogenesis of vascular complications in patients with diabetes mellitus.…”