A three-year prospective, randomized and open comparison between latanoprost and timolol in Japanese normal-tension glaucoma patients

Purpose To compare the longitudinal effects of treatment on intraocular pressure (IOP) and visual field performance in Japanese normal-tension glaucoma (NTG) between latanoprost and timolol. Patients and methods This is an open-label, randomized, study. A total of 62 NTG patients were prospectively, consecutively enrolled. All study subjects were randomly assigned to 0.005% latanoprost instillation once daily in the morning or 0.5% timolol instillation twice daily for a prospective 3-year follow-up, and underwent a routine ocular examination every month. Automated perimetry was performed every 6 months using Humphrey field analysers. Stereophotographs of optic discs were also obtained every 6 months. Results Percentage of IOP reduction or the magnitude of IOP reduction showed no intergroup differences either at any time point ( 13 - 15%). In the visual field, the estimated rate of change in the MD value (dB/year) was - 0.34 +/- 0.17 ( SE) for the latanoprost group, and - 0.10 +/- 0.18 ( SE) for the timolol group. The estimated rate of change in MD showed no significant difference from zero in both groups, and there were no statistical intergroup differences. No changes in the optic nerve head topography in the vertical cup-to-disc ratio and rim area measured by image-analysis techniques were observed in either group. There were no patients who dropped out due to the side effects of treatment regimens. Conclusion Both latanoprost and timolol single treatments reduced IOP by 13 - 15% at their trough effects for 3 years in Japanese NTG patients; both showed similar effects on visual field performance.