Selective binding of a 30-kilodalton protein to disposable hydrophilic contact lenses.

To investigate the accumulation of tear proteins on disposable extended-wear contact lenses (42% Etafilcon A and 58% hydration), a technique involving sodium dodecyl sulfate-polyacrylamide minigel electrophoresis combined with a sensitive silver-staining method was used. Besides the binding of large amounts of tear lysozyme the authors found an accumulation of an as yet unidentified 30-kilodalton (kD) protein. Longitudinal experiments showed lysozyme binding after 1 day of lens wear. The 30-kD protein was detected after a 2-day wearing period. The fact that protein deposition occurs during the relatively short wearing period of these lenses (1 week) may explain the unexpectedly high incidence of contact lens-associated conjunctivitis observed with these lenses.