Preservative-free tafluprost/timolol fixed combination: comparative 24-h efficacy administered morning or evening in open-angle glaucoma patients.

: Ideal dosing for the preservative-free (PF) tafluprost/timolol fixed combination (TTFC) remains to be elucidated. : 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.