The Association between Corneal Biomechanical Properties and Initial Visual Field Defect Pattern in Normal Tension Glaucoma

Purpose: To investigate the association between corneal biomechanical properties and initial visual field defect pattern in normal tension glaucoma using an Ocular Response Analyzer (ORA; Reichert Instruments, Depew, NY, USA). Methods: Forty-one patients with normal tension glaucoma were divided into 2 subgroups, 21 patients with initial paracentral scotomas and 20 patients with initial peripheral scotomas. The corneal biomechanical properties of corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), corneal-compensated IOP (IOPcc) measured by the ORA, central corneal thickness, and Goldmann applanation tonometry were comparatively analyzed between the 2 groups. Results: The patients with initial peripheral scotomas were significantly younger than those with initial paracentral scotomas (49.45 ± 13.33 years vs. 58.14 ± 12.49 years, p = 0.035) and showed more myopia (-2.42 ± 2.22 diopter vs. -0.89 ± 2.22 diopter, p = 0.034). The mean CRF was significantly lower in the initial paracentral scotoma group than in the initial peripheral scotoma group. (9.45 ± 1.95 mmHg vs. 10.58 ± 2.05 mmHg; p = 0.041). No significant difference in CH, IOPg, or IOPcc was seen between the groups. Conclusions: CRF was significantly different between the initial paracentral scotoma group and initial peripheral scotoma group in normal tension glaucoma. Thus, CRF may be useful to predict initial central field loss in normal tension glaucoma. J Korean Ophthalmol Soc 2017;58(2):178-184