title: Prothrombotic states associated with retinal venous occlusion in young adults.
abstract: BACKGROUND
  The etiology of retinal venous occlusion in young patients is not well understood although thrombosis does occur histologically. A search for the risk factors that may lead to thrombosis is highly desirable may contribute to our understanding of the pathogenesis of this complication and may improve our therapeutic strategies.
  
  
  METHODS
  We studied 17 patients with retinal venous occlusion. All patients were under 45 years of age (mean 37.8 +/- 7.1). Antiphospholipid antibodies (APAs) and certain hemostatic factors were determined. The results obtained in these patients were compared to those of normal controls.
  
  
  RESULTS
  We found APAs in 8 out of 17 patients compared to 5 out of 60 controls (p = 0.0002). In patients with major trunk occlusion, there was a trend for the presence of APAs in those with poor visual acuity at presentation. Deficiencies of the coagulation inhibitor proteins C and S and antithrombin III activities were detected in 6 patients, and reduced levels of Factor XII were found in 4 patients. Levels of hematocrit, erythrocyte sedimentation rate. Fibrinogen, alpha 1-globulin, and alpha 2-globulin were significantly higher in patients compared to the controls (p = 0.019; 0.014; 0.0001; 0.011; 0.047), indicating increased blood viscosity in patients with retinal venous occlusion.
  
  
  CONCLUSIONS
  Prothrombotic changes in the form of APAs and/or deficiencies of coagulation inhibitors and Factor XII may contribute to the etiology of retinal venous occlusion in young adults. Young patients with retinal venous occlusion should be evaluated for these prothrombotic states.
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 K
authors.initials: AK
authors.lastname: al-Momen
authors.forename: S
authors.initials: S
authors.lastname: al-Amro
authors.forename: A G
authors.initials: AG
authors.lastname: Abdel Gader
authors.forename: K F
authors.initials: KF
authors.lastname: Tabbara
mesh_terms: D000328:Adult; D017153:Antibodies, Anticardiolipin / Q000378:metabolism; D000974:Antibodies, Antinuclear / Q000378:metabolism; D017152:Antibodies, Antiphospholipid / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D007122:Immunoelectrophoresis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012170:Retinal Vein Occlusion / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood / Q000150:complications* / Q000276:immunology
chemical_list: D017153:Antibodies, Anticardiolipin; D000974:Antibodies, Antinuclear; D017152:Antibodies, Antiphospholipid; D001798:Blood Proteins