The effects of short-term contact lens wear on adherence of Pseudomonas aeruginosa to human corneal cells.

BACKGROUND: Ulcerative keratitis is the most serious complication of contact lens wear, with the majority of infections being attributed to Pseudomonas aeruginosa. The degree to which bacteria adhere to the cornea may indicate its susceptibility to infection. It has been found that long-term contact lens wear leads to increased adherence of Pseudomonas aeruginosa to corneal epithelial cells. This study examines the effect of short-term contact lens wear. MEANS: Cells were collected using a non-contact corneal irrigation system from a total of 16 subjects fitted with tight and loosely-fitted soft contact lenses. The control group consisted of 10 subjects with no recent contact-lens-wearing experience, eight of whom were later fitted with lenses to form a neophyte group. Six contact lens wearers formed the experienced group. After wearing lenses for a 30-hour period, including overnight, the collected corneal cells were incubated with Pseudomonas aeruginosa, differentially stained with Acridine orange and examined under fluorescence microscopy.

RESULTS: The number of bacteria adhering to the cells was determined for the control group, neophyte and experienced groups. The frequency distribution profiles were similar for all groups and did not vary significantly between lens-wearing and non-wearing conditions, between neophyte and experienced wearers, or with lens fit.

CONCLUSIONS: Using the technique reported, short-term extended contact lens wear produced minimal detectable changes in the potential of corneal epithelium cells to bind bacteria.