title: Prevalence of factor V Leiden and activated protein C resistance in central retinal vein occlusion.
abstract: OBJECTIVE
  Factor V Leiden is a common inherited mutation that is a significant risk factor for deep vein thrombosis. It results in resistance to activated protein C (APC). The association between factor V Leiden and central retinal vein occlusion (CRVO) remains controversial. This study was designed to determine the prevalence of APC resistance and the factor V Leiden mutation in patients with CRVO in a controlled study.
  
  
  METHODS
  The study was designed as a case control study conducted in a tertiary care retina practice. The prevalence of APC resistance and factor V Leiden was determined by genetic testing of blood samples obtained from patients with CRVO and clinic control patients.
  
  
  RESULTS
  Factor V Leiden was identified in 2.3% of patients with CRVO and 3.5% of clinic control patients. There was no significant association between the presence of factor V Leiden and CRVO (odds ratio, 1.13; 95% confidence interval, 0.65-1.98; P = 0.66).
  
  
  CONCLUSIONS
  Factor V Leiden does not appear to be associated with CRVO. Routine screening of patients with CRVO does not appear to be warranted.
authors.affiliation: University of Ottawa Eye Institute, Ontario, Canada.
authors.forename: T M
authors.initials: TM
authors.lastname: Johnson
authors.forename: S
authors.initials: S
authors.lastname: El-Defrawy
authors.forename: W G
authors.initials: WG
authors.lastname: Hodge
authors.forename: B C
authors.initials: BC
authors.lastname: Leonard
authors.forename: P J
authors.initials: PJ
authors.lastname: Kertes
authors.lastname: Taylor SAM
authors.forename: D P
authors.initials: DP
authors.lastname: Lillicrap
mesh_terms: D020016:Activated Protein C Resistance / Q000097:blood / Q000150:complications*; D000368:Aged; D016022:Case-Control Studies; D005165:Factor V / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012170:Retinal Vein Occlusion / Q000097:blood / Q000150:complications*; D012307:Risk Factors
chemical_list: C095381:factor V Leiden; D005165:Factor V