Background: To examine the association between the polymorphisms of the endothelial nitric oxide synthase (eNOS) gene and the occurrence of non-arteritic anterior ischemic optic neuropathy (NAION).
Methods: We studied 15 patients with NAION (mean age, 62 years; 60% male). We investigated two polymorphisms of the eNOS gene, Glu298Asp polymorphism of exon 7 and T(-786)C polymorphism of the promoter region. The genotype distribution in NAION was compared with the control (mean age, 63 years; 63% male) distribution.
Results: There was no significant difference in the genotype distribution of the Glu298Asp polymorphism between the NAION and control groups (P = 1.000), whereas the genotype dis-tribution of the T(-786)C polymorphism varied significantly between the patients with NAION and control subjects (P = 0.002). After adjusting on covariates, individuals with the CC genotype of the T(-786)C polymorphism were more likely to develop NAION compared with those with TT genotype (odds ratio = 0.09: 95% CI 0.01-0.86).
Conclusions: We found an increased prevalence of T(-786)C polymorphism of the eNOS gene in patients with NAION. Our data suggest that the T(-786)C polymorphism of the eNOS gene may be an important risk factor in the development of NAION in Japanese subjects.