A Review of Techniques to Measure Protein Sorption to Soft Contact Lenses

TitleA Review of Techniques to Measure Protein Sorption to Soft Contact Lenses
Publication TypeJournal Article
Year of Publication2017
AuthorsHall, B., J. Forrest, and L. Jones
JournalEye and Contact Lens
Keywordsadsorption, atomic force microscopy, attenuated total internal reflection, attenuated total internal reflection infrared spectroscopy, biological activity, circular dichroism, colorimetry, confocal laser scanning microscopy, contact lens, Contact lenses, Diagnostic Techniques, electron microscopy, ellipsometry, enzyme activity, eye protein, Eye Proteins, human, Humans, Hydrophilic, hydrophilic contact lens, lysozyme, mass spectrometry, metabolism, Ophthalmological, priority journal, Protein activity, protein analysis, protein binding, Protein conformation, Protein deposition, protein function, Protein quantity, protein secondary structure, protein sorption, protein tertiary structure, quartz crystal microbalance, radiochemistry, Review, soft contact lens, visual system examination, X ray photoelectron spectroscopy

Purpose: To compare and critically evaluate a variety of techniques to measure the quantity and biological activity of protein sorption to contact lenses over short time periods. Methods: A literature review was undertaken investigating the major techniques to measure protein sorption to soft contact lens materials, with specific reference to measuring protein directly on lenses using in situ, ex situ, protein structural, and biological activity techniques. Results: The use of in situ techniques to measure protein quantity provides excellent sensitivity, but many are not directly applicable to contact lenses. Many ex situ techniques struggle to measure all sorbed proteins, and these measurements can have significant signal interference from the lens materials themselves. Techniques measuring the secondary and tertiary structures of sorbed proteins have exhibited only limited success. Conclusions: There are a wide variety of techniques to measure both the amount of protein and the biological activity of protein sorbed to soft contact lens materials. To measure the mass of protein sorbed to soft contact lenses (not just thin films) over short time periods, the method of choice should be I 125 radiolabeling. This technique is sensitive enough to measure small amounts of deposited protein, provided steps are taken to limit and measure any interaction of the iodine tracer with the materials. To measure the protein activity over short time periods, the method of choice should be to measure the biological function of sorbed proteins. This may require new methods or adaptations of existing ones. © 2017 Contact Lens Association of Ophthalmologists.