title: Hyperhomocysteinemia: a new risk factor for central retinal vein occlusion.
abstract: OBJECTIVE
  Previous studies have documented that an elevated plasma homocysteine level is a risk factor for vascular disease. The purpose of this study is to determine whether hyperhomocysteinemia is a risk factor for central retinal vein occlusion.
  
  
  METHODS
  This case-controlled study involved reassessment of 74 patients with documented central retinal vein occlusion. Control subjects consisted of individuals referred to the same clinic for assessment of a nonretinal vascular disease. Hyperhomocysteinemia was defined as a total plasma homocysteine level above the 95th percentile in the control group.
  
  
  RESULTS
  The mean total plasma homocysteine level was 11.58 mumol/L for cases and 9.49 mumol/L for controls. Of the 74 patients with a central retinal vein occlusion, 21.6% had total plasma homocysteine levels above the 95th percentile in the control group (odds ratio, 6.53; 95% confidence interval, 1.81 to 23.50, P = .003). Hyperhomocysteinemia was present in 55% of cases with bilateral disease, 30% of ischemic cases, and 31% of cases with severe visual loss.
  
  
  CONCLUSIONS
  Hyperhomocysteinemia is a risk factor for central retinal vein occlusion.
authors.affiliation: University of Michigan Medical School, Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, Ann Arbor, Michigan, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Vine
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications*; D007511:Ischemia / Q000097:blood / Q000150:complications; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012170:Retinal Vein Occlusion / Q000097:blood / Q000150:complications / Q000209:etiology* / Q000503:physiopathology; D012171:Retinal Vessels; D012307:Risk Factors; D014786:Vision Disorders / Q000097:blood / Q000209:etiology; D014792:Visual Acuity
chemical_list: D006710:Homocysteine