PURPOSE. The interaction of lipoidal species with surface and matrix of soft contact lens materials is important in the development of spoilation resistant contact lenses and successful ocular prostheses. Lipids are highly reactive molecules, which interact with the surface of a contact lens and are also readily absorbed into the lens matrix. Once in the lens matrix these species are no longer in close contact with the antioxidants in the superficial tear layer and may alter their chemical structure. These altered lipoidal species are less readily desorbed from the lens matrix and may provide a site for further deposition to occur. The aim of this study was to profile the type of extractable lipids from daily disposable and thirty night continuous wear contact lenses. METHOD. A number of contact lenses, which had been worn on a daily wear basis or for thirty nights continuously, were collected. The gross levels of lipids were assessed using fluorescence spectrophotofluorimetry on collection and after extraction of the lipids for further analysis. The lipid profiles were determined using high performance liquid chromatography.
RESULTS. The lipid patterns for both the surface deposition and extractable lipid profiles were variable between patients. Patient-based effects outweighed those related to wear time. The type of lens material also played a role in the type of lipid laid down on the lens.
CONCLUSIONS. Variations in patient lipid deposition profiles are known to be greater than protein deposition patterns. Although wear period is a progressive driver of deposition it is outweighed by materials dependence and patient to patient variation. Wear time becomes an important issue for the small but significant number of heavy lipid spoilers. There is a need to match the patient to the lens type and wear schedule in order to minimise these problems.