Tears contain ~60 different proteins that adhere to contact lenses, causing lens deterioration and ocular pathology. We examined the adhesion of three tear proteins to two different types of FDA Group II contact lenses (hilafilcon and omafilcon). Lenses were incubated in 2.0 mg/ml solutions of human lysozyme, albumin and transferrin for 1–4 days. Protein adhesion was determined by bicinchoninic acid assay. Lysozyme adhered to hilafilcon lenses in an up‐down pattern, with a maximum on day 3. Lysozyme adhesion to omafilcon lenses was high after 1 day and remained high on day 4. Albumin adesion to both types of lenses was high after 1 day, declined, and increased on day 4. Transferrin adhesion to both lenses was initally low, increasing to a maximum on day 3 and declining on day 4. These results are due to differences in lens material and tear protein structure. Hilafilcon, more negatively charged than Omafilcon, absorbed more lysozyme (+ charged at physiological pH). Omafilcon lenses are coated with phosphorylcholine, reducing adhesion by the hydrophobic domains of albumin. Human apo‐transferrin has few positive charges and thus bound more reluctantly to both materials.Supported by the Farquhar College of Arts and Sciences and the Health Professions Division, NSU.

Human tears contain ~60 different proteins that accumulate on contact lenses. We examine the adhesion of human transferrin to FDA Group II Omafilcon A contact lenses, fabricated from a biomimetic material whose interaction with tear proteins is not well characterized and for which the consequences of protein accumulation are unclear. Omafilcon A lenses were incubated in human transferrin for five days, and protein adhesion was determined by bicinchoninic acid colorimetry on a daily basis. Transferrin adhered to the Omafilcon A lenses to a lesser extent (~10%) than it did to Alphafilcon A lenses (also FDA Group II). Our previous data indicate the same is true for lysozyme adhesion, with Omafilcon A lenses adsorbing less lysozyme (~25%) than Alphafilcon A lenses. Levels of transferrin and lysozyme adhesion to Omafilcon A lenses are lower than their levels of adhesion to any other type of contact lenses in all four FDA groups, suggesting that Omafilcon A lenses are better able to resist protein adhesion than contact lenses fabricated from other materials.Supported by a NSU President's Faculty Scholarship Award, the NSU Health Professions Division, and the Farquhar College of Arts and Sciences at NSU.

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Tear proteins accumulate on contact lenses causing lens deterioration and conjunctival irritation. We examined the adhesion of transferrin to contact lenses made of tisifilcon A, a rigid gas‐permeable silicone hydrogel (FDA Group III). Lenses were incubated 2.0 mg/ml solutions of human holo‐transferrin for 1, 2, 3, and 4 days, and protein adhesion was determined by bicinchoninic acid assay. Transferrin adhesion increased from day 0 to day 3 and then dropped after days 4 and 5. This pattern resembled transferrin adhesion to lenses made of polymacon (FDA Group I), alphafilcon (FDA Group II), omafilcon (FDA Group II) and balafilcon (FDA Group III) materials, but differed from the pattern of transferrin adhesion to etafilcon (FDA Group IV) material. Transferrin adhesion to tisifilcon A was greater than transferrin adhesion to all other materials except balafilcon, which had equivalent transferrin adhesion. These differences may be related to the positive charges on transferrin originating from arginine residues and the N‐terminus. These cause transferrin to adhere better to the low water ionic Group III materials than to the non‐ionic materials (FDA Groups I and II) and the high water ionic material (FDA Group IV).Supported by the Farquhar College of Arts and Sciences at NSU and the Menicon Company, Ltd.