Adhesion of human lysozyme to balafilcon A (FDA Group III) Contact Lenses.

Abstract

The adhesion of tear proteins to contact lenses contributes to lens deterioration and ocular pathology. Tears contain a number of proteins, predominantly lysozyme. Here we examine the adhesion of human lysozyme to FDA group III (low water, ionic) contact lenses comprised of a copolymer of silicon vinyl carbamate, N‐vinyl‐pyrrolidone, with a siloxane crosslinker and a vinyl alanine wetting monomer. These lenses are 36% water by weight. Lenses were incubated in a solution of lysozyme for 1, 2, 3, and 4 days, and protein adhesion was determined using the bicinchoninic acid assay. In contrast to our previous study, where non‐human lysozyme adhered to contact lenses from all four FDA Groups in an up‐down‐up‐down pattern, human lysozyme adhered to these lenses in an early peak and subsequently decreasing fashion. The concentration of lysozyme in the incubation solution decreased rapidly, becoming almost undetectable by the fifth day of the experiment, and this may have limited lysozyme adhesion during the later days of the experiment. These lenses appear to have a high affinity for lysozyme, in keeping with the ionic nature of the polymers from which they were made. Supported by a NSU President's Faculty Scholarship Award and the Farquhar College of Arts and Sciences.