Adhesion of Transferrin to FDA Group II Contact Lenses

Adhesion of Transferrin to FDA Group II Contact Lenses

Approximately 75 million people worldwide use contact lenses for vision correction. Tears contain roughly 60 different proteins that accumulate on the lens, contributing to lens deterioration, and leading to vision problems and ocular pathology. We examined the adhesion of transferrin FDA Group II contact lenses, and compared these results to previous results examining the adhesion of lysozyme, albumin, and transferrin to lenses from the other FDA material groups: Group I - Optima FW disposable lenses (Bausch and Lomb, Inc. Rochester NY, U.S.A.); Group II - Soflens one-day disposables (Bausch and Lomb, Inc.); Group III - PureVision continuous wear disposables (Baush and Lomb Inc.); and Group IV - AcueVue disposables (Vistakon, Jacksonville, FL, USA). Lenses were incubated in a solution of each protein for 1, 2, 3, and 4 days, and protein adhesion was determined using the bicinchoninic acid assay (Pierce Chemical Co., Rockford, IL, USA). Transferrin adhered to Group II lenses in an increasing asymptotic pattern, where the levels increased each day during the incubation, reaching a maximum after three days of incubation, and then declining slightly on the fourth day. The pattern of transferrin adhesion to these lenses differed from the patterns observed for lysozyme and albumin adhesion to the same lenses. Average transferrin adhesion to Group II lenses was 72 (±30) ug/lens, as compared to 11 (±5.5) for lysozyme and 46.5 (±34) for albumin.

With respect to transferrin adhesion to lenses from FDA Groups I and IV, average transferrin adhesion to Group I lenses was 96 ug/lens (± 10), as compared to 70 (± 13) for lysozyme and 60 (± 24) for albumin. Average transferrin adhesion to Group IV lenses was 116 ug/lens (± 43), as compared to 92 (± 6) for lysozyme and 49 (± 4) for albumin. Transferrin adsorbed to Group I lenses in a steadily increasing pattern, resembling the pattern of albumin but not lysozyme. Transferrin adsorbed significantly to Group IV lenses after one day, and remained elevated resembling the pattern seen with lysozyme and albumin. This variation suggests the need for further studies of the complex interactions between tear proteins and contact lenses.