Hyperhomocyst(e)inaemia, but not MTHFR C677T mutation, as a risk factor for non-arteritic ischaemic optic neuropathy.
OBJECTIVE
Hyperhomocyst(e)inaemia has been identified as a strong risk factor for stroke, myocardial infarction, and deep vein thrombosis. A point mutation of methylene tetrahydrofolate reductase (MTHFR C677T) has been associated with increased plasma homocyst(e)ine levels. To investigate whether hyperhomocyst(e)inaemia and/or MTHFR C677T mutation are associated with non-arteritic ischaemic optic neuropathy (NAION), a case-control study including 59 consecutive patients with NAION and 59 controls matched for age and sex was performed.


METHODS
Fasting plasma homocyst(e)ine levels, MTHFR C677T genotypes, and plasma levels of folate and vitamin B-12 were determined.


RESULTS
Mean plasma homocyst(e)ine levels were significantly higher in patients than in controls (11.8 (SD 5.7) micromol/l v 9.8 (2.5) micromol/l, p = 0.02). The odds ratio for patients with homocyst(e)ine levels exceeding the 95th percentile of control homocyst(e)ine levels was 5.8 (95% CI 1.5-21.4). Mean plasma folate levels were significantly lower in patients than in controls (4.3 (1.7) ng/ml v 5.5 (1.9) ng/ml, p = 0.001), whereas plasma vitamin B-12 levels did not differ significantly. Prevalence of the MTHFR C677T mutation was not significantly increased in patients with NAION compared with controls.


CONCLUSIONS
These results suggest that hyperhomocyst(e)inaemia, but not MTHFR C677T mutation is associated with NAION. Determination of plasma homocyst(e)ine levels might be of diagnostic value in patients with NAION.
Weger
M
M
Department of Ophthalmology, Karl-Franzens University, Graz, Austria. martin.weger@kfunigraz.ac.at
Stanger
O
O
Deutschmann
H
H
Simon
M
M
Renner
W
W
Schmut
O
O
Semmelrock
J
J
Haas
A
A
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D005492:Folic Acid / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications* / Q000235:genetics; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D018917:Optic Neuropathy, Ischemic / Q000097:blood / Q000209:etiology* / Q000235:genetics; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D017354:Point Mutation; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood
D015415:Biomarkers; D005492:Folic Acid; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12