title: Influence of Tear Protein Deposition on the Oxygen Permeability of Soft Contact Lenses.
abstract: Purpose. To investigate the effect of tear protein deposition on the change in oxygen permeability (Dk) of soft contact lenses (SCL).Methods. Three hydrogel lenses (polymacon, nelfilcon A, and etafilcon A) and two silicon hydrogel lenses (lotrafilcon A and balafilcon A) were investigated. Etafilcon A lenses were incubated in artificial tear solution for 1, 6, 12, and 48 h, whereas the other SCL were incubated for 1, 3, 7, and 14 days. Oxygen permeability was measured using the polarographic method, and lenses were stacked in four layers to correct the boundary effect.Results. TheDkof all investigated SCL was decreased by the protein deposition. Silicone hydrogel lenses showed a smaller deposition of artificial tear proteins than conventional hydrogel lenses. However, theirDkwas reduced twofold than those of 3 conventional hydrogel lenses when compared at the same level of protein deposition. Despite a large amount of total deposited protein in etafilcon A lenses, theirDkwas more stable than other SCL.Conclusions. From the results, it was revealed that theDkof SCL is different from the value provided by manufacturers because of the tear protein deposition on surface and/or in pore of SCL; however, the degree ofDkchange in SCL was not simply correlated with the amount of tear protein deposition. Thus, it is considered that the correlation between tear protein deposition and properties of lens materials affectsDkchange.
authors.affiliation: Department of Optometry, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea.
authors.forename: Se Eun
authors.identifier: 0000-0002-7647-7492
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Optometry, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea.
authors.forename: So Ra
authors.identifier: 0000-0001-8786-2815
authors.initials: SR
authors.lastname: Kim
authors.affiliation: Department of Optometry, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea.
authors.forename: Mijung
authors.identifier: 0000-0002-4645-7415
authors.initials: M
authors.lastname: Park