Differential Bacterial Colonization and Biofilm Formation on Punctal Occluders

Dry eye is a common condition that is treated primarily by topical lubricants, immunomodulation, and a variety of punctal and canalicular plugs (occluders). Biofilm formation has been reported as an ongoing problem with the clinical use of occluders. In order to explore the role of biofilm formation on occluders, we tested the bacteria strain, Staphylococcus aureus, with three different types of occluders, Delta^R, Odyssey^R, and Alphamed^R. Scanning electron microscopy (SEM) of these occluders revealed a variation in surface appearance, with Odyssey^R being the smoothest (but with grooves), followed by Delta^R, and Alphamed^R. Exposing each type of occluder to dynamically grown bacterial cultures of S. aureus, a ~3 fold statistically significant difference in bacteria colonization between the Odyssey^R and Alphamed^R occluder and a ~2 fold higher trend between Odyssey^R and Delta^R were detected. These quantitative results were also verified with SEM, showing extensive S. aureus colonization and biofilm formation on the surface of the Odyssey^R occluder. The results also indicate that bacterial colonization readily occurs on all three types of occluders. The occluder with the smoothest but grooved surface (Odyssey^R), displayed increased biofilm formation when compared to those with rougher surfaces.