Introduction: We examined the sustainability of the intraocular pressure (IOP)-lowering efficacy of travoprost (0.004%) ophthalmic solution in subjects with normal tension glaucoma (NTG).
Methods: Travoprost ophthalmic solution was given once daily at 9 PM to subjects with newly diagnosed NTG or with NTG who had not received any ocular hypotensives within the previous 30 days. IOP was measured at three time points (9 AM, 1 PM, and 5 PM) at baseline and week 12 visits, and at one time point (9 AM) at week 4 and week 8 visits. Conjunctival hyperemia, superficial punctate keratopathy, and other adverse events were evaluated during the observation period.
Results: Thirty subjects (12 males and 18 females; mean age 65.6 years) from 32 subjects enrolled were included in the efficacy analysis. The mean IOPs (±standard deviation) of 16.6 ± 1.4, 15.7 ± 1.8, and 15.7 ± 2.2 mmHg at 9 AM, 1 PM, and 5 PM, respectively, at baseline reduced significantly to the mean IOPs of 13.0 ± 1.8, 12.7 ± 1.8, and 12.8 ± 1.6 mmHg, respectively, at week 12 (P < 0.0001 for every time point). Together with the mean IOPs of 13.4 ± 1.9 mmHg at week 4 and 13.2 ± 1.9 mmHg at week 8, the pooled IOP during the observation period for up to 12 weeks showed a statistically and clinically significant reduction of IOP at 9 AM. (3.4 mmHg or 20.3% reduction from baseline, P < 0.0001). There were no adverse events leading to treatment discontinuation.
Conclusion: This multi-center collaborative study suggests that IOP-lowering efficacy of travoprost ophthalmic solution persists during the day at the clinically relevant level in subjects with NTG.
Funding: Alcon Japan Ltd.
Trial registration: University Hospital Medical Information Network, UMIN ID: 000011621.
Keywords: IOP-lowering; Intraocular pressure (IOP); Normal tension glaucoma; Sustainability; Travoprost.