The Association Between Corneal Biomechanical Properties and Progression of Visual Field Loss in Normal Tension Glaucoma

ABSTRACT

PURPOSE: To evaluate the association between corneal biomechanical properties and progression of visual field loss in normal tension glaucoma. METHODS: This study enrolled 73 eyes of 73 patients with normal tension glaucoma who were undergoing medical treatment, and classified them into progressing and nonprogressing groups by visual field trend analysis. The corneal biomechanical properties measured by the Ocular Response Analyzer (ORA; Reichert Instruments, Depew, NY, USA), central corneal thickness, and Goldmann applanation tonometry were comparatively analyzed between the 2 groups. RESULTS: Twenty-six eyes reached a progression endpoint. The prevalence of hypertension was higher in the progressing group (42.3%, progressing, 17.0%, nonprogressing; p = 0.03). Progressing eyes had lower corneal hysteresis (9.1 +/- 1.3 vs. 9.8 +/- 1.5 mm Hg, p = 0.03) and lower corneal resistance factor (9.5 +/- 1.5 vs. 10.4 +/- 1.4 mm Hg, p = 0.01) compared with nonprogressing eyes. Upon multivariate analysis, the presence of hypertension (odds ratio [OR] = 3.46, p = 0.03) and corneal hysteresis (CH) (OR = 0.66 per mm Hg lower, p = 0.02) remained statistically significant. CONCLUSIONS: The CH measurement with ORA was significantly associated with risk of visual field progression in normal tension glaucoma. Eyes with lower CH had a greater risk of progression of visual field loss than those with higher CH.