Observation of deposits on disposable contact lenses by bio-, light and scanning electron microscopy.

There has been little published on the presence of deposits on disposable hydrogel contact lenses. The purpose of the present study was to determine the possible existence of such deposits. Seventy-two disposable lenses (polymacon; FDA group 1; non-ionic, low water contact lenses) were fitted to six patients and replaced weekly in the course of a total follow-up period of six weeks. By means of biomicroscopy, light microscopy and scanning electron microscopy, different types of deposits were observed on all the lenses studied. Our results also indicate that the accumulation rate of these deposits expressed as a percentage of the total area of the lens which they covered increased after the third replacement of the lenses over the 4th, 5th and 6th weeks. Finally, we observed that the amount of deposits varies in the different patients studied in the course of a 6 week follow-up period.