Abstract
Abstract: :
Purpose: To compare the adherence of Pseudomonas aeruginosa and other bacteria to the leading daily disposable and frequent replacement (Groups II and IV) lenses. Nelfilcon A and HEMA–like material lenses including etafilcon A, omafilcon, vifilcon A, vasurfilcon A, alphafilcon A, hilafilcon, and ocufilcon D were tested. A comparison of the relative adherence to these hydrogel lenses using invasive and cytotoxic strains of Pseudomonas was investigated. Methods: Lenses were suspended in 1x10E8/ml challenge organisms for 14 hours at 350C while shaking. A sonication and release procedure was performed on unworn lenses and lenses pre–conditioned with an artificial tear fluid. Results: Nelfilcon A lenses allowed the lowest number of adherence among all substrata tested both in the presence or absence of a film induced from artificial tear fluid. The bacterial adherence to different types of hydrogel lenses by Pseudomonas aeruginosa invasive strain was much higher than with the cytotoxic strain. Maximal adherence by Staphylococcus species to hydrogels was typically lower than of Pseudomonas. Conclusions: The PVA containing nelfilcon A hydrogel may help lower the number of bacteria adhered to the lens. This, in turn, may reduce the potential risk of microbial–related adverse events.
Keywords: Pseudomonas • contact lens • Staphylococcus