Clinical factors associated with progression of normal-tension glaucoma

Purpose: To investigate clinical factors associated with the progression of visual field loss in normal-tension glaucoma (NTG). Methods: One hundred and ten patients with NTG whose cases were followed for more than 2 years were retrospectively analyzed with the Kaplan-Meier life table method and the Cox proportional hazards model. Several clinical factors were investigated to find a possible association with progression of glaucomatous visual field defined by two different definitions: one by mean deviation change and the other by pointwise comparison. Results: The Cox proportional hazards model indicated that change in the visual field was significantly associated with treatment with calcium channel blockers, recovery rate from a cold recovery test, systolic blood pressure, disc hemorrhage, corrected pattern standard deviation, mean deviation, and fluctuation of intraocular pressure (IOP) at a 24-hour phasing. The probability of nonprogression of visual field loss was significantly higher for patients taking calcium channel blockers than-for control subjects by either definition of visual field progression. Conclusion: Factors other than IOP, including the use of calcium channel blockers, are associated with the outcome of visual field loss in NTG.