Purpose:

The purpose of this study is to determine the association between common point-of-care tear tests (osmolarity and matrix metalloproteinase 9 (MMP-9)) and severity of Meibomian gland dysfunction (MGD) as measured by meibography.

Methods:

A retrospective study was performed at a single academic center analyzing data from 7/2016 to 7/2018. Patients were identified by electronic medical record diagnosis of MGD and/or dry eye disease (DED). They were included for study if they had undergone lower lid meibography of both eyes via Lipiview ™ and either tear osmolarity, MMP-9, or both. Patients were excluded if they had used topical anti-inflammatory medications within 3 months of testing. Severity of MGD (meiboscore) for each lower eyelid was independently graded by two ophthalmologists and averaged based on the meiboscale grading system (grade 0-4). Statistical results were analyzed using Chi-Squared or Fischer’s Exact tests.

Results:

A total of 79 patients met inclusion for this study. There was no statistically significant association between meiboscore and positive MMP-9 (≥grade 2: n=50, p=0.173; ≥grade 3: n=31, p=0.296; grade 4: n=21, p=0.3). The average meiboscore difference between those with abnormal tear osmolarity compared to those with normal tear osmolarity was 0.378 points higher, which was not statistically significant (p= 0.117). The difference in meiboscore in a patient with both abnormal osmolarity and positive MMP-9 was 0.25 points higher than in patients with both normal osmolarity and negative MMP-9 (p = 0.02), which was statistically significant.

Conclusions:

There was no statistically significant association between the severity of MGD and either tear osmolarity or MMP-9. However, patients that had both abnormal tear osmolarity and positive MMP-9 were more likely to also have worse meiboscores. As each test measures a different endpoint of OSD, there may be benefit in employing all available tests.