Purpose: Dry eye disease (DED) is a common condition resulting from tear film disruption and ocular surface inflammation. Matrix Metalloprotein-9 (MMP-9) is an inflammatory mediator found in tears that is associated with DED. This study investigated the relationship between a point of care MMP-9 test and the severity of DED as measured by signs and symptoms to determine if MMP-9 is a viable biomarker for DED diagnosis.

Methods: Participants in the Dry Eye Assessment and Management (DREAM) study received MMP-9 point-of-care testing at screening and 3 months. Associations between MMP-9 results and Keratography testing (noninvasive keratograph breakup time, tear meniscus height, bulbar redness), clinical examinations (Tear-Break-Up-Time, Schirmer test, Meibomian gland secretions/plugging, tear osmolarity, conjunctival staining, corneal staining), and the Ocular Surface Disease Index (OSDI) were analyzed.

Results: Among the 211 subjects (422 eyes) analyzed, the mean age was 57.7 ± 13.3 years and 79% were female. Preliminary analysis showed the following a significantly higher percentage of male subjects than female subjects were MMP-9 positive (70% vs. 51%, P = 0.01). Post-menopausal status (p = 0.02) and tear IFN-gamma levels (p = 0.047) at baseline were also significantly associated with MMP-9 positivity. No other cytokines or HLA-DR gene positivity at baseline were significantly associated with MMP-9 levels. No significant associations were found between baseline MMP-9 and DED measures at baseline or 3-month follow-up. No significant relationship between change in MMP-9 status and change in DED symptoms/signs was observed.

Conclusions: In the DREAM study, a significant relationship was found between baseline MMP-9 positivity and sex, post-menopausal status, and tear IFN-gamma levels. MMP-9 point-of-care testing status was not associated with DED severity as measured by signs and symptoms.

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