Thrombophilic factors as the trigger of retinal vessel occlusions

Purpose. Thrombophilic abnormalities and defects in the anticoagulant syste m, such as protein C or protein S deficiency,activated protein C resistance and factor V Leiden mutation, may produce retinal vascular occlusions. Patients. Blood samples from 66 consecutive retinal vascular occlusion pati ents were obtained and analysed for protein C resistance and fibrinolysis a ctivity. Other thrombophilic and standard laboratory coagulant tests were a lso carried out. Results. An increased activity of factor VIII was found in 72% of the colle ctive. Further more, 24% of all patients and 32% of patients younger than 4 5 years old were resistant to activated protein C. Nevertheless only one pa tient showed a homozygotous factor V Leiden mutation. Conclusion. Thrombophilic activity in cases of protein C resistance or fact or V Leiden mutation may result in severe thrombotic manifestations in ocul ar vessels. Compared to the elderly, younger people sh owed a higher activa ted protein C resistance which seems be one of the most common causes for r etinal vascular occlusion in this age group.