PAAO-YO Research: Dr. Matias Soifer, MD

26 January 2021

Dr. Matias Soifer, MD is a Cornea & Ocular Immunology Fellow at Duke Eye Center. Below are the salient points of an article he recently published with links to the article.

Matrix metalloproteinase 9 positivity predicts long term decreased tear production

Dry Eye is a multifactorial disease with an inflammatory component. One of the recognized elements of the inflammation is the presence of matrix metralloproteinases which cleave epithelial junctions and attract inflammatory mediators. A commercially available device, named Inflammadry, measures qualitatively the presence of Matrix Metalloproteinase-9 (MMP-9) in the ocular surface. However most of its studies are cross sectional, therefore it is not known which are the long term implications of testing positive or negative for MMP-9 over time. The purpose of this study was to investigate long-term correlations between Matrix Metalloproteinase-9 (MMP-9) testing and dry eye (DE) parameters. Additionally, to evaluate variability in MMP-9 results over time and with anti-inflammatory treatment.
For that, we conducted a retrospective cohort study of DE patients with equal MMP-9 testing results (positive or negative) in both eyes and a minimum of 6 months of follow up. Our main outcome measure was to examine whether initial MMP-9 status affected change in DE parameters, such as a symptoms questionnaire, osmolarity, Schirmer’s test, Tear break up time and corneal staining over time. Secondarily, we evaluated the frequency of MMP-9 status change over time and examined whether MMP-9 status change was impacted by treatment.

67 patients (76% female) met the inclusion criteria. Mean age was 63 years with a mean follow up of 10.6 months. The majority (37/67, 55%) had concomitant systemic immune disease. MMP-9 testing was positive in both eyes in 39 individuals (58%) and negative in both eyes in 27 (42%) individuals. Of all DE parameters, initial MMP status predicted change in tear production. Individuals in the MMP-9 positive group had a greater decrease in production from baseline to final visit compared to the negative group (2.6 vs 2.1 mm, P = 0.013). In those initially MMP-9 positive, the frequency of becoming MMP-9 negative was higher in eyes treated with anti-inflammatory therapy compared to artificial tears (22.9% vs 3.3%, P = 0.106). However, only Lifitegrast 5% showed statistical significance compared to artificial tears (31.3% vs 3.3%, P = 0.044). As a conclusion, our data demonstrates that positive detection of MMP-9 is associated with significantly decreased tear production over time compared to those without detectable MMP-9. Anti-inflammatory treatment more frequently normalized MMP-9 compared to PFATs.


  • Matrix Metalloproteinase-9 (MMP-9) is a biomarker of inflammation in dry eye.
  • Via Inflammadry, we studied MMP-9 long term associations with dry eye parameters.
  • Positive detection of MMP-9 was associated with long term decrease tear production.
  • Anti-inflammatory treatment normalized MMP-9 detection on the ocular surface.

Soifer M, Mousa HM, Stinnett SS, Galor A, Perez VL. Matrix metalloproteinase 9 positivity predicts long term decreased tear production. Ocul Surf. 2020 Oct 21; S1542-0124(20)30159-2. doi: 10.1016/j.jtos.2020.10.003. Online ahead of print.


Erick Hernandez Bogantes MD

Matias Soifer, MD
Cornea & Ocular Immunology Fellow
Duke University Eye Institute