Effect of preservative-free tafluprost on keratocytes, sub-basal nerves, and endothelium: a single-blind one-year confocal study on naïve or treated glaucoma and hypertensive patients versus a control group.

To record the impact of preservative-free Tafluprost on corneal status examined by in vivo confocal microscopy. A prospective cohort study on consecutive naïve or previously treated patients with a new prescription of preservative-free Tafluprost. All subjects underwent a complete ophthalmic examination [comprehensive of intraocular pressure (IOP) and central corneal thickness (CCT) measurements], and an in vivo corneal confocal microscopy evaluation, at baseline and 12 months later. A healthy control group was selected and examined at the same time. Seventy-five subjects (16 controls, 20 naïve, and 39 treated) were enrolled. At baseline, IOP was 16 (13.8-18.6), 21.5 (18-23.7), and 18 (16-22) mmHg, (P=0.01); and CCT did not differ among the groups (P=0.25). Epithelial cells, keratocyte activation, a number of sub-basal nerves, and the grade of nerve tortuosity were similar (P=0.233, 0.11, 0.417, and 0.05, respectively), in naïve and controls, while previously treated patients had significantly less epithelial cells and sub-basal corneal nerves (P<0.0001), keratocyte activation, increased number of bead-like formations, and nerve tortuosity (P<0.0001). At month 12, IOP decreased in both patient groups (P<0.001); CCT did not change. Previously treated patients showed an improvement in confocal parameters: increased epithelial cells (P=0.0006), reduced keratocyte activation (P=0.003), increased number of corneal nerves (P=0.0004), decreased number of bead-like formations (P=0.0013), and nerve tortuosity (P=0.0008). Naïve patients did not show significant changes. The study confirmed the efficacy of preservative-free Tafluprost in reducing IOP, and underlined the drug's safety in naïve glaucoma patients with regard to corneal status. In the balance between efficacy and tolerability, formulations with low cytotoxicity may ensure fewer side effects, with higher tolerability and better compliance.