Deposits on soft contact lenses. Electrophoresis and scanning electron microscopic examinations

Deposits on soft contact lenses were studied by several methods, microscopic examination, scanning electron microscopy, electron microprobe and electrophoresis on polyacrylamide gels of removed proteins. The first two approaches permitted classification of deposits into globular deposits, "Mulberry-like growths", opaque deposits, protein films and red spots. The electron microprobe indicated specific compositions of each. The electrophoretic technique demonstrated the presence of lysozyme in all the deposit types, with other unidentified proteins or degradation peptides. Whatever the deposit type, heat disinfection is not advisable since proteins are always present. Combination of chelating agents and oxidizing products are logically to be preferred for cleaning lenses.