To investigate the risk factors related to the location of visual field defects in normal tension glaucoma.

Eighty-one eyes diagnosed as normal tension glaucoma in patients with early glaucomatous visual field defects were divided into central visual field defects and peripheral visual field defects. The difference between the 2 groups based on the intra-individual comparison were assessed with several ocular risk factors such as sex, age, hypertension, diabetes mellitus, smoking, laterality, intraocular pressure, central corneal thickness, cup-disc ratio, peripapillary atrophy, mean deviation, pattern standard deviation, best corrected visual acuity, and refractive errors.

The incidence of hypertension in the central visual field defects group (60.6%) was higher than in the peripheral visual field defects group (22.9%, p = 0.001). The central corneal thickness in the central group (533.1 ± 18.2 µm) was thinner than in the peripheral group (545.0 ± 30.0 µm, p = 0.003). Hypertension was the only risk factors for central visual field defects ( p = 0.001). In both the central group and peripheral group, upper visual field defects were more common than lower defects.

Hypertension in patients with normal tension glaucoma was a factor involved in central visual field defects. Additionally, numerous visual field defects were mainly found the superior portion.