Carbohydrate deposits on the surfaces of worn extended-wear soft contact lenses
S. A. Klotz, R. P. Misra and S. I. Butrus
Three different commercial extended-wear soft contact lenses worn
continuously by patients for at least 28 days were stained with fluorescein
isothiocyanate-labeled lectins. These lectins detected the presence of
alpha-linked or beta-linked D-mannose, D-glucose, D-galactose, L-fucose,
N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and N-acetyl neuraminic
acid (sialic acid) on the surfaces of the contact lenses. These saccharides
are bound to other sugars that likely account for an integral part of
glycoprotein and/or glycolipid deposits on lens surfaces. These tear
deposits may contribute to the chemical spoilage of the lens and,
furthermore, may serve as specific receptors for pathogenic microorganisms
commonly implicated in extended-wear soft contact lens-associated
infectious keratitis.
