Comparison of Circadian Efficacy of Tafluprost Eye Drops (Taflotan Sine®) with Latanoprost Eye Drops (Xalatan®) in the Treatment of Open-Angle Glaucoma and Ocular Hypertension

<b>Background/Objectives:</b> To investigate the non-inferiority of preservative-free (PF) tafluprost eye drops (Taflotan sine^®) compared to latanoprost eye drops (Xalatan^®) in reducing mean 24 h intraocular pressure (IOP) on the second day of a diurnal IOP measurement. <b>Methods:</b> In this retrospective monocentric cohort study, patients suffering from primary open-angle glaucoma, ocular hypertension, normal tension glaucoma, pigment dispersion glaucoma, or pseudoexfoliation glaucoma who had undergone inpatient diurnal IOP measurement were included. Patients of cohort 1 used latanoprost eye drops as monotherapy; patients of cohort 2 used preservative-free tafluprost eye drops. Data from 7 January 2005 to 9 July 2019, inclusive, were analyzed. <b>Results:</b> Ninety-three eyes were included (n = 59 latanoprost group, n = 34 PF tafluprost group). Mean 24 h IOP on day 2 was 14.1 mmHg (SD 2.3) in the latanoprost group and 14.5 mmHg (SD 3.4) in the PF tafluprost group. The non-inferiority of PF tafluprost eye drops to latanoprost eye drops in efficacy on mean 24 h IOP could not be confirmed (95% CI -1.5, ∞, <i>p</i> = 0.235). The average difference in mean IOP at the individual measurement times between both cohorts was 0.24 mmHg (SD 0.17) on day 1 and 0.44 mmHg (SD 0.6) on day 2. The non-inferiority of PF tafluprost compared to latanoprost regarding fluctuation range could not be demonstrated for both days. <b>Conclusions:</b> The data suggests slight inferiority of PF tafluprost to latanoprost eye drops. There were similar mean 24 h IOP values in both cohorts. PF tafluprost eye drops remain a useful treatment option as long as the patient's individual target pressure is achieved. Furthermore, according to the literature, it is also a treatment option for patients with symptoms of ocular surface disease and other side effects affecting the ocular surface while receiving preservative-containing topical therapy.