The role of hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) C677T mutation in patients with retinal artery occlusion.
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.
Weger
Martin
M
Department of Ophthalmology, Karl-Franzens University, Graz, Austria. martin.weger@kfunigraz.ac.at
Stanger
Olaf
O
Deutschmann
Hannes
H
Leitner
Franz Josef
FJ
Renner
Wilfried
W
Schmut
Otto
O
Semmelrock
Jürgen
J
Haas
Anton
A
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
D006710:Homocysteine; D004247:DNA; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)