Attachment of Pseudomonas to Human-Worn, Disposable Etafilcon A Contact Lenses

Jacksonville, FL, U.S.A.; etafilcon A) lenses were soaked in a Pseudomonas aeruginosa suspension (1.4 x 108 cfu/ ml). New Acuvue lenses served as controls. A single strain of P aeruginosa harvested from a human corneal ulcer was used throughout the experiment. Lenses were examined by culture and scanning electron microscopy (SEM). We found significantly greater (p c0.05) bacterial attachment to new Acuvue lenses [culture, 3.1 x 104 (±0.82 x 104 cfu/mm2; SEM, 2.6 x 104 (±.0.47 x 104) bacteria/mm2] compared with those previously worn [culture, 1.0 x 104 (±.0.17 x 104) cfu/mm2; SEM, 0.73 x 104 (±.0.21 x 104) bacteria/mm2]. No statistical difference was found among the individuals. Our findings demonstrate that the biological coating resulting from 1 week of continuous contact lens wear restricts P. aeruginosa attachment to the Acuvue lens when comparing new and used lenses.