The Effect of Enzymatic Contact Lens Cleaning on Adherence of Pseudomonas aeruginosa to Soft Contact Lenses

Previous studies have demonstrated that Pseudomonas aeruginosa adheres more readily to soft contact lenses with a mucin coating than to unworn contact lenses. The mucin coatings that develop on soft contact lenses may, therefore, play a significant role in the pathogenesis of contact lens-associated Pseudomonas corneal ulceration. We tested the ability of a variety of enzymatic contact lens cleaners and other enzyme solutions to decrease the adherence of Pseudomonas to mucin-coated soft contact lenses. Of the commercially available solutions that were tested, cleaning with Optizyme® and Extenzyme® significantly reduced the adherence of Pseudomonas to the lenses, whereas cleaning with the Softmate Weekly Cleaning System® had no effect. Optizyme® and Extenzyme® were as effective as a 10% solution of acetylcysteine and more effective than a 0.25% trypsin solution. Neuraminidase at pH 5 was the most effective solution at reducing the adherence of Pseudomonas to the lenses, supporting the finding that sialic acid is a specific receptor for Pseudomonas aeruginosa. Soft contact lenses should be cleaned frequently with an effective enzymatic cleaner to reduce the likelihood of Pseudomonas adhering to the lens and thereby reduce the incidence of Pseudomonas corneal ulceration in soft contact lens wearers.