title: The role of hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) C677T mutation in patients with retinal artery occlusion.
abstract: OBJECTIVE
  Hyperhomocysteinemia has been established as an important risk factor for cardiovascular diseases. The aim of the present study was to investigate whether hyperhomocysteinemia and/or homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T mutation are associated with an increased risk for retinal artery occlusion (RAO).
  
  
  METHODS
  Retrospective case-control study.
  
  
  METHODS
  We studied 105 consecutive patients with retinal artery occlusion and 105 age and sex-matched control subjects. Fasting plasma homocysteine levels were determined by high-performance liquid chromatography, while genotypes of the MTHFR C677T mutation were determined by polymerase chain reaction.
  
  
  RESULTS
  Mean plasma homocysteine levels were significantly higher in patients with RAO compared with control subjects (12.2 +/- 4.8 micromol/l vs 10.3 +/- 3.4 micromol/l; P =.003). Hyperhomocysteinemia was defined by the 95th percentile of control plasma homocysteine levels as 15.8 micromol/l. Twenty (19.1%) patients with RAO exceeded this level and were therefore classified as hyperhomocysteinemic compared with 5 (4.8%) control subjects (P =.003). The odds ratio for these patients was calculated at 4.7 (95% confidence interval [CI], 1.5-15.1). Mean plasma folate levels were significantly lower in patients than in the control group (5.6 +/- 2.3 ng/ml vs. 6.3 +/- 2.5 ng/ml; P =.04). The prevalence of the homozygous genotype of methylenetetrahydrofolate reductase C677T mutation did not significantly differ between patients and controls.
  
  
  CONCLUSIONS
  Our results suggest that hyperhomocysteinemia, but not homozygosity, for the MTHFR C677T mutation is associated with RAO.
authors.affiliation: Department of Ophthalmology, Karl-Franzens University, Graz, Austria. martin.weger@kfunigraz.ac.at
authors.forename: Martin
authors.initials: M
authors.lastname: Weger
authors.forename: Olaf
authors.initials: O
authors.lastname: Stanger
authors.forename: Hannes
authors.initials: H
authors.lastname: Deutschmann
authors.forename: Franz Josef
authors.initials: FJ
authors.lastname: Leitner
authors.forename: Wilfried
authors.initials: W
authors.lastname: Renner
authors.forename: Otto
authors.initials: O
authors.lastname: Schmut
authors.forename: Jürgen
authors.initials: J
authors.lastname: Semmelrock
authors.forename: Anton
authors.initials: A
authors.lastname: Haas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000032:analysis; D005260:Female; D005838:Genotype; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications* / Q000235:genetics; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D015356:Retinal Artery Occlusion / Q000097:blood / Q000209:etiology* / Q000235:genetics; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D006710:Homocysteine; D004247:DNA; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)