Influence of intraocular pressure reduction on progression of normal-tension glaucoma with myopic tilted disc and associated risk factors

Purpose To evaluate the influence of intraocular pressure (IOP) reduction on progression of normal-tension glaucoma (NTG) with myopic tilted disc and to demonstrate the associated risk factors. Methods The medical records on 109 eyes of 109 NTG patients with myopic tilted discs who were followed up for more than 5 years and treated with topical medications were reviewed. Glaucoma progression was defined according to either structural or functional deterioration. Patients were divided into tertile groups according to the percent IOP reduction from the baseline, and the cumulative probability of NTG nonprogression of the upper- and lower-tertile groups was compared using Kaplan-Meier survival analysis. The multivariate Cox proportional hazards model was used to identify the risk factors for glaucoma progression. Results Forty-nine of 109 eyes (45.0%) showed glaucoma progression after the average follow-up period of 7.55 +/- 1.79 years. The Kaplan-Meier analysis revealed a greater cumulative probability of nonprogression for the upper-tertile group (percent IOP reduction > 20.9%) than for the lower-tertile group (percent IOP reduction < 12.9%; P = 0.016). The Cox proportional hazards model indicated that presence of disc hemorrhage was a factor associated with glaucoma progression (HR = 3.664; P = 0.001). Conclusions Lower-percent reduction in IOP was associated with NTG progression in eyes with myopic tilted discs, and the presence of disc hemorrhage was a risk factor for NTG progression.