Morphological, histochemical and X-ray microanalytical examination of deposits on soft contact lenses in extended wearing.

The deposits on 29 contact lenses of various water content from 20 wearers were analysed by the methods given in the title. Six lenses were used as bandage lenses, the remaining for optical correction. The age of the patients varied from 7 to 56 years, two-thirds being under 45 years. Wearing time had been from 1 week to 1 year, with an average of 13 weeks. The results obtained by the methods applied showed that calcium was present in just over two-thirds of the cases (20/29), other elements being infrequent. Mucopolysaccharides were found in just under two-thirds (18/29). Chlorine was present in one-fifth of the cases. No significant amounts of lipid were detected. Fungi were found in three cases (3/29). Bacteria were also found in these cases, but never without fungi. Evaluation of the methods applied showed that the methods of choice were macroscopical examination and scanning microscopy in combination with X-ray microanalysis, in a few cases combined with histochemistry. None of the methods applied is sufficient for protein analysis.