Ocular tear fluid biomarkers collected by contact lenses

To collect tear fluid biomarkers from contact lenses (CLs) and determine the impact of CL wear duration.

Rabbits were fitted with commercial etafilcon A CLs, which were collected after 1 min, 4 and 8 h (n = 4/time point). Tear fluid proteins and cytokines were extracted from the CLs and quantified. An exploratory comparison was performed between CLs and Schirmer Strips (SS) for a 1 min duration.

The concentration of MUC5AC was significantly higher after 4 h of CL wear. The expression of all investigated cytokines (IL-1α, IL-1β, IL-8, IL-17A, IL-21, Leptin, MIP-1β, MMP-9, NCAM-1, and TNF-α) was detectable after 1 min of CL wear, and over time, all showed significant variations throughout the 8-h CL wear period. Notably, IL-1α significantly increased by 8 h of CL wear, while MMP-9 decreased. Albumin and lysozyme did not show significant variations with CL wear. Differences between CLs and SS after 1 min were statistically significant for albumin, Leptin, TNF-α, IL-1α, IL-1β, and IL-8.

The duration of CL wear significantly affects the collection of some tear fluid biomarkers. Albumin, MUC5AC, and cytokines may have individual and synergistic diagnostic or prognostic potential. CLs and SS were similar for lysozyme and MUC5AC but differed in the collection of albumin and some cytokines. CLs are a viable tear fluid collection method for biomarker analyses and can be immediately added as a routine clinical test by being FDA-approved medical devices.