Purpose: To assess whether genetic polymorphisms of optic atrophy 1 (OPA1) are associated with primary open-angle glaucoma (POAG).
Design: Prospective case control association study.
Methods: Japanese patients with normal tension glaucoma (NTG, n = 194), and high tension glaucoma (HTG, n = 191), and 185 control subjects were analyzed for the OPA1 intervening sequence (IVS) 8+4 cystosine thymine (C/T) and IVS 8+32 thymine cystosine (T/C) polymorphisms using pyrosequencing technique.
Results: There was a significant difference in the OPA1 IVS 8 +32 T/C genotype frequencies between the NTG patients and control subjects (P = .0074), and the frequency of the cystosine (C) allele was significantly higher in the NTG patients compared with the control subjects (19.3% vs 11.6%, P = .0036). Adjusted for age, gender, refractive error, and intraocular pressure, an almost two-fold increased risk of NTG (P = .004, odds ratio 2.27, 95% confidence interval 1.30 to 3.97) was found with the OPA1 IVS 8 +32 C allele. Although there was no significant difference in the OPA1 IVS 8 +32 T/C genotype frequencies between the HTG patients and control subjects (P = .24), the age at the time of diagnosis (53 +/- 11.0 years, median value +/- median absolute deviation) in the HTG patients with the OPA1 IVS 8 +32 C allele was significantly younger than that (57 +/- 12.0 years) in the HTG patients without C allele (P = .048).
Conclusions: The OPA1 IVS 8 +32 T/C polymorphism is associated with NTG, and may be used as a marker for this disease association. This polymorphism also influences the phenotypic feature in patients with HTG and should be considered to be a genetic risk factor not only for NTG, but also for HTG.