Optic disc size and progression of visual field damage in patients with normal-tension glaucoma

Abstract

Fukuko Hayamizu, Yoshio Yamazaki, Takako Nakagami, Kenji MizukiDepartment of Ophthalmology, Division of Visual Science, Nihon University School of Medicine, Tokyo, JapanPurpose: Our goal was to evaluate the influence of optic disc size on the progression of visual field damage in patients with normal-tension glaucoma (NTG).Subjects and methods: Eighty-two eyes of 82 NTG patients who had been receiving topical antiglaucoma medications and followed-up for more than 4 years were enrolled in this study. The patients were allocated to two groups, according to the mean size of their optic discs. The data were analyzed using regression analysis, based on the Cox proportional hazard model.Results: The probability of visual field stability was significantly lower in eyes with large discs than in those with small discs (log rank test, P = 0.007). Progression of visual field damage was significantly associated with the optic disc area (hazard ratio [HR]: 1.812, P = 0.018), occurrence of disc hemorrhage (HR: 2.116, P = 0.028), and intraocular pressure reduction ratio (HR: 0.957, P = 0.014).Conclusion: The optic disc area correlates with progression of visual field damage in patients with NTG.Keywords: Cox proportional hazards model, disc hemorrhage, disc size, intraocular pressure, Kaplan–Meier life-table analysis