Background: Ideal dosing for the preservative-free (PF) tafluprost/timolol fixed combination (TTFC) remains to be elucidated. Research design and methods: This study was a prospective, observer-masked, placebo-controlled, crossover, comparison in 42 consecutive open-angle glaucoma patients whose intraocular pressure (IOP) was insufficiently controlled with preserved latanoprost monotherapy (mean 24-h IOP >20 mmHg). Patients were randomized to either morning (08:00) or evening (20:00) PF TTFC for 3 months and then crossed over. After each treatment period, patients underwent habitual 24-h IOP monitoring with Goldmann tonometry in the sitting position (at 10:00, 14:00, 18:00, and 22:00) and Perkins tonometry in the supine position (at 02:00 and 06:00). Results: Mean 24-h IOP on latanoprost was 22.2±3.9 mmHg. Both PF TTFC dosing regimens obtained greater reduction in mean 24-h, daytime, nighttime, and peak 24-h IOP (P < 0.001). Evening dosing provided tighter 24-h IOP fluctuation versus latanoprost (P < 0.001). Evening dosing was superior to morning dosing at four time points (P < 0.01), for the mean daytime IOP (P < 0.001) and mean 24-h IOP fluctuation (P < 0.001). Hyperemia was more common with preserved latanoprost (21.4 vs. 7.1%; P = 0.031). Patients (n = 19; 45%) preferred evening dosing. Conclusions: PF TTFC provided greater 24-h IOP control and less hyperemia compared with preserved latanoprost. Evening administration of this novel medication offered superior 24-h efficacy. Trial registration: Clinicaltrials.gov (NCT03612817).
Keywords: 24-h efficacy; BAK; Taptiqom; hyperemia; latanoprost; preservative-free tafluprost/timolol fixed combination; tafluprost.