Interactions of bacteria with contact lenses: the effect of soluble protein and carbohydrate on bacterial adhesion to contact lenses.

PURPOSE

During contact lens wear, components in the tear film adsorb to the contact lens surface to form a protein-rich coating. In this study, we investigated the importance of these components in bacterial adhesion to contact lenses.

METHODS

Five strains of bacteria were tested for their ability to adhere to contact lenses (patient-worn; coated with lactoferrin, lysozyme, or an artificial tear formulation; or left uncoated) in the presence of various solutes (protein, carbohydrate). Bacterial adhesion was quantified by both a total count (light microscopy) and viable count (culturing on agar).

RESULTS

None of the solutes were found to competitively inhibit bacterial adhesion to worn contact lenses. However, lactoferrin was observed to kill bacteria attached to worn contact lenses.

CONCLUSIONS

We could find no evidence to indicate that bacterial adhesion to contact lenses is mediated by specific interactions between bacteria and contact lens-bound tear components. The interaction between attached bacteria and lactoferrin may be important in initiating inflammatory responses to contact lens wear.