Effects of BAK-free travoprost treatment for 3 years in patients with normal tension glaucoma

BACKGROUND: The purpose of this study was to evaluate the effects of benzalkonium (BAK)-free travoprost monotherapy administered for 3 years on intraocular pressure and visual field performance. METHODS: The intraocular pressure of 76 patients with normal tension glaucoma was monitored every 1–3 months. A Humphrey visual field test was performed every 6 months after treatment and compared with the results before treatment. Visual field performance was also evaluated by trend and event analysis. RESULTS: Thirty cases discontinued within 3 years. Mean intraocular pressure after 3 years of travoprost treatment (14.1 ± 2.4 mmHg) was significantly lower than that before treatment (16.8 ± 2.6 mmHg, P < 0.0001). There was no change in the mean deviation and pattern standard deviation as measured by Humphrey visual field test after 3 years of treatment compared with before treatment. Visual field performance was worse in one patient (2.8%) by trend analysis and five patients (13.9%) by event analysis. Treatment was discontinued in six cases (7.9%) due to the appearance of adverse reactions. CONCLUSION: BAK-free travoprost monotherapy was effective in reducing intraocular pressure for at least 3 years; however, visual field performance worsened in 2.8%–13.9% of patients with normal tension glaucoma.