title: Hypercoagulable states in patients with retinal venous occlusion.
abstract: OBJECTIVE
  The pathogenesis of thrombus formation in the retinal vein resulting in retinal vein occlusion is not well understood. This study was carried out to ascertain the role of hypercoagulable states in patients with retinal vein occlusion.
  
  
  METHODS
  Fifty seven consecutive patients with acute retinal vein occlusion (mean age 48 +/- 11.5 years) were investigated for possible hypercoagulable states. Levels of antithrombin III (AT III), protein C (PC), Protein S (PS), factor XII, and fibrinogen as well as the presence of antiphospholipid antibodies (APAs) were investigated. The APAs and fibrinogen results obtained in these patients were compared to those of healthy controls.
  
  
  RESULTS
  We detected APAs in 15 out of 57 patients compared to 3 out of 74 controls (p = 0.0002). Fibrinogen levels were significantly higher in patients compared with the controls (p < 0.001). Deficiencies in the naturally occurring anticoagulant proteins including AT III (4 out of 54 patients tested), PC (8 out of 42 patients tested), and PS (12 out of 56 patients tested) were detected. Seven patients out of 32 patients tested had reduced levels of factor XII. Subgroup analysis of the thrombophilic differences between patients who aged 45 years or less and older patients and patients with major trunk vein occlusion and patients with branch vein occlusion revealed no significant differences.
  
  
  CONCLUSIONS
  Hypercoagulable states are common in patients with retinal vein occlusion and may contribute to the etiology of the disease.
authors.affiliation: Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: A M
authors.initials: AM
authors.lastname: Abu El-Asrar
authors.forename: A G
authors.initials: AG
authors.lastname: Abdel Gader
authors.forename: S
authors.initials: S
authors.lastname: Al-Amro
authors.forename: A K
authors.initials: AK
authors.lastname: Al-Momen
mesh_terms: D000328:Adult; D000368:Aged; D017152:Antibodies, Antiphospholipid / Q000378:metabolism*; D000990:Antithrombin III / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D005174:Factor XII / Q000378:metabolism*; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011486:Protein C / Q000378:metabolism*; D017293:Protein S / Q000378:metabolism*; D012170:Retinal Vein Occlusion / Q000097:blood* / Q000209:etiology; D012307:Risk Factors
chemical_list: D017152:Antibodies, Antiphospholipid; D015415:Biomarkers; D011486:Protein C; D017293:Protein S; D000990:Antithrombin III; D005174:Factor XII; D005340:Fibrinogen