Quantitative assay of protein deposits on hydrophilic contact lenses treated with renu®1 and complete®2 solutions

The purpose of this study was to investigate the protein deposit cleaning ability of new ReNu® MultiPlus™ (ReNu®¹) and new COMPLETE® brand ComfortPLUS™ Multi-Purpose Solution (COMPLETE®²) on hydrophilic contact lenses. New never-worn hydrophilic contact lenses (SUREVUE®³ etafilcon A, 58%) were used. Contact lenses were incubated in artificial tear solution for in vitro soaking; human-worn lenses were collected for in vivo assay. The measurements were performed using a UV spectrophotometer. The cleaning efficacy of COMPLETE® on protein deposits was significantly better than that of ReNu®. In the in vitro experiment, COMPLETE® removed about two times the amount of deposits than ReNu® did. In an in vivo experiment, the difference was even more remarkable. The differing cleaning efficacies of the two solutions may be due to differences in their pH, buffers, or cleaning components. The difference was not due to soaking time, as each solution reached a peak point after which no additional protein deposits were removed.