Evaluations of Tear Protein Markers in Dry Eye Disease: Repeatability of Measurement and Correlation with Disease.
Purpose: To characterize tear protein markers in dry eye disease (DED).
Methods: In this prospective study, based on Ocular Surface Disease Index© (OSDI) and corneal staining (CS), 95 DED patients (OSDI≥13) with increasing CS were enrolled into 3 severity groups: DE1 (CS<4), DE2 (CS between 4 and 7) and DE3 (CS>7); 25 asymptomatic subjects with no CS were enrolled into control (OSDI<13 and CS=0). Tear fluid was collected at Day 0 and Day 7 visits and concentrations of 43 protein markers were measured by multiplexed immunoassay.
Results: 22 control and 80 DED subjects were analyzed. Among 33 markers detectable, good inter-visit repeatability was observed with 25 markers, with intraclass correlation coefficients (ICC) ranging from 0.85 to 0.60; ICCs were below 0.60 in the other 8. Correlation with clinical measures was found with two markers, with absolute partial correlation coefficients greater than 0.40: Interleukin-1 Receptor Antagonist (IL-1Ra) and IL-8. IL-1Ra and IL-8 correlated with conjunctival staining (0.43, P < .001 and 0.35, P < .01, respectively), and with Schirmer test (-0.58 and -0.42, P < .001). IL-1Ra and IL-8 in DE3 were 4.4 and 2.1 fold higher than in DE1 (P=.0001 and .0007), 1.9 and 1.6 fold higher than in DE2 (P =.022 and .017). IL-1Ra in DE2 was 2.3 fold higher than in DE1 (P=.038).
Conclusion: Tear levels of many immune mediators were highly repeatable between visits in DED. Among them, IL-1Ra and IL-8 associated with clinical signs and disease severity defined by corneal staining.
Invest Ophthalmol Vis Sci. 2012 Jun 13. [Epub ahead of print]
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