Abstract: Protein biomarkers in contact lens dry eye

Very interesting.

I would like to better understand what they mean by "contact lens-related dry eye". It doesn't seem as though they're simply distinguishing between CTL wearers with and without dry eye, but at a practical level how could they distinguish those with ctl-related dry eye from dry eye independent of ctls?

Mass Spectrometry-Based Proteomic Analyses in Contact Lens-Related Dry Eye.
Cornea. 2009 Sep 16. [Epub ahead of print]
Nichols JJ, Green-Church KB.
From the Campus Chemical Instrumentation Center Mass Spectrometry and Proteomics Facility, College of Optometry, Ohio State University, Columbus, OH.

PURPOSE:: To identify potential protein biomarkers associated with dry eye in contact lens wearers.

METHODS:: Upon enrollment, current galyfilcon A contact lens wearers completed a previously described questionnaire used to classify dry eye status. Approximately 5 muL of aqueous tears were carefully sampled from the inferior-lateral tear prism of each eye using glass microcapillaries. A variety of proteomic approaches were used to compare samples including quantification by Bradford analyses, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) (alone in varying percentages and with MultiPlex analyses for posttranslational modifications), nano-liquid chromatography tandem mass spectometry (nano-LC-MS/MS), and differential gel electrophoresis.

RESULTS:: Twenty-one subjects were enrolled in the study (age 31.3 +/- 11.6 years). Eleven of the subjects were classified with contact lens-related dry eye, while the remaining 10 were normal contact lens wearers. Across all proteomic approaches, several proteins (including several glycoproteins) were identified as potential biomarkers associated with dry eye disease state. In summary across the approaches used, extracellular proteins identified to be altered included beta-2 microglobulin, proline rich 4, lacritin, and secretoglobin 1D1, which were found to be decreased in the dry eye state. Secretoglobin 2A2, serum albumin, glycoprotein 340, and prolactin-inducible protein were all found to be increased in the dry eye state.

CONCLUSIONS:: Dry eye in contact lens wearers is related to several changes in the tear film protein. While functional studies for these candidate proteins are ongoing, initial insights into the functions of these proteins suggest roles in altered tear secretion, in addition to possible increased susceptibility to infection.