The nature and consequence of vitronectin interaction in the non-compromised contact lens wearing eye

Purpose: The aim of this work was to investigate the locus and extent of vitronectin (Vn) deposition on ex vivo contact lenses and to determine the influence of wear modality together with surface and bulk characteristics of the lens material. Methods: The quantity and location of Vn deposition on the surfaces of contact lens materials was investigated using a novel on-lens cell attachment assay technique. Results: Vn mapping showed that deposition resulted from lens-corneal interaction rather than solely from the tear film. Higher cell counts on the posterior surface of the lenses were determined in comparison to the anterior surface. Overall gross Vn deposition was greater for high water content-low modulus materials (117. ±. 4 average cell count per field) than low water content-high modulus materials (88. ±. 6 average cell count per field). Conclusions: The role of Vn in plasmin regulation and upregulation is widely recognised. The findings in this paper suggest that the locus of Vn on the contact lens surface, which is affected by material properties such as modulus, is potentially an important factor in the generation of plasmin in the posterior tear film. Consequently, the potential for materials to affect Vn deposition will influence lens-induced inflammatory processes.