PURPOSE: The purpose of this research is to evaluate the relationship between of optic atrophy 1 (OPA1) polymorphism and normal tension glaucoma (NTG) by surveying patients from central Taiwan. This study finding could help us to understand the impact of OPA1 polymorphism on glaucoma. METHODS: We try to identify the effect of OPA1 polymorphism by comparing the clinical presentation in three catalogs of gene polymorphism in patients with NTG. Our research team includes patients with NTG from central Taiwan and assesses the OPA1 intervening sequence 8 (IVS8) + 4 C->T and IVS8 + 32 T->C polymorphism. We divide these patients into three OPA1 IVS8 + 4 subgroups, CC, CT, TT, and three IVS8 + 32 subgroups, TT, TC, CC. By collecting their ocular clinical data, systemic background, and other possible factors related to the presentation of glaucoma, we can compare these characters of each polymorphism subgroup. RESULTS: We find that all patients do not have OPA1 IVS8 + 4 C->T polymorphism while some of them do have IVS8 + 32 T->C polymorphism. NTG with OPA1 IVS8 + 32 T->C polymorphism inclines to have more nasal-step type visual field defect (P = 0.016) and inferior nerve fiber layer thickness loss (P = 0.098) in comparison to NTG with IVS8 + 32 wild type. CONCLUSIONS: The OPA1 IVS8 + 32 T->C polymorphism partake to the phenotype and prognosis of NTG in central Taiwan. Even though our findings are far from clear enough to serve as guides for the differentiation of NTG etiologies, they still give us a glimpse of the impact of OPA1 in chronic optic neuropathy.