Genetic polymorphisms associated with endothelial function in nonarteritic anterior ischemic optic neuropathy

PURPOSE To examine the relationship between nonarteritic anterior ischemic optic neuropathy (NAION) and genetic polymorphisms of enzymes influencing endothelial function. METHODS The subjects were 34 patients with NAION (mean age, 62.4 years old; 59% male) and 102 controls (mean age, 63.8 years old; 66% male). Genetic polymorphisms were investigated in three candidate genes associated with endothelial function: endothelin-1 (ET-1), angiotensin-converting enzyme (ACE), and methylenetetrahydrofolate reductase (MTHFR). The genotype distributions in the patients with NAION were compared with those in the controls. RESULTS There were no significant differences in the genotype distributions of the ACE I/D and MTHFR C677T polymorphisms between the NAION and control groups (p=0.261 and p=0.354, respectively), whereas the genotype distribution of the G/T (Lys198Asn) polymorphism of the ET-1 gene varied significantly between the groups (p=0.009). After adjusting for covariates, individuals with the TT genotype of the Lys198Asn polymorphism were more likely to develop NAION compared with those with the GG genotype (odds ratio=4.43, 95% confidence interval 1.33-14.73, p=0.015). CONCLUSIONS We found an increased prevalence of a G/T polymorphism of the ET-1 gene in patients with NAION. Our data suggest that this polymorphism may be an important risk factor in developing NAION in the Japanese population.