Periorbital Changes Induced by Prostaglandin Eye Drops.

Purpose Taflotan® (tafluprost) and Monoprost® (latanoprost) are preservative‐free anti‐glaucoma eye drops. In order to compare the ocular irritation potential these preservative‐free prostaglandin products were instilled repeatedly on rabbit eyes. Cell viability in vitro was studied using immortalized human corneal epithelial (HCE) cells.Methods To study the in vitro cytotoxicity of Taflotan and Monoprost, HCE cells were exposed to the test solutions for 5 to 30 minutes, after which the cytotoxicity was evaluated by MTS assay. Secondly, to compare their in vivo ocular tolerance, Taflotan or Monoprost solution was instilled 10 times at 30‐minute intervals onto eyes of male albino rabbits. Left eyes were treated while right eyes remained as untreated controls. Besides scoring macroscopic findings using MacDonald‐Shadduck system, slit lamp examination and corneal fluorescein staining were performed after the last instillations.Results In MTS test, the 30 minutes treatment with Taflotan had no effect on the cell viability, whereas the cell viability was decreased by Monoprost treatment. After repeated instillations on rabbit eyes conjunctival redness and swelling were observed in both groups. Their irritation scores and occurring frequency were lower in Taflotan treated eyes than in those treated with Monoprost. In addition, discharge was observed only in Monoprost treated eyes from 30 minutes until 3 hours after the last instillation.Conclusion Under the conditions of this study, the ocular irritation potential of Taflotan was weaker than that of Monoprost. The results indicate that Taflotan eye drops may have a better ocular tolerability profile than Monoprost. Commercial interest