Thierry Bilbault

Cleaning capability of citrate-containing vs. non-citrate contact lens cleaning solutions: An in vitro comparative study

The cleaning capability of citrate and the comparative capability of Opti-One™ Multi-Purpose Solution and ReNu® Multi-Purpose Solution were assessed by the removal of lysozyme deposits from Group IV hydrogel contact lenses. The in vitro model used DuraSoft® 3 lenses deposited with fluorescently labeled dansyl-lysozyme. Quantitative determination of the dansyl-lysozyme removed was accomplished by fluorescence spectrophotometry. The results demonstrated that solutions containing citrate, Opti-One Multi-Purpose Solution, and Test Solution A (Opti-One without Polyquad®), removed significantly (p < 0.05) more dansyl-lysozyme than did test solutions without citrate and ReNu Multi-Purpose Solution (a surfactant-based cleaner). This was accomplished by soaking in the test solutions (passive cleaning) and did not involve a digital rub of the lenses. The citrates mode of action is thought to involve complexation with and displacement of lens-associated lysozyme into the aqueous cleaning solution medium.