March 2012
Volume 53, Issue 3
Free
Letters to the Editor  |   March 2012
Correlation between Tear Matrix Metalloproteinases and the Schirmer's Test
Author Affiliations & Notes
  • Louis Tong
    The Ocular Surface Research Group, Singapore Eye Research Institute, Singapore;
    the Singapore National Eye Center, Singapore;
    the Duke-NUS Graduate Medical School, Singapore; and
    the Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
  • Andrea Petznick
    The Ocular Surface Research Group, Singapore Eye Research Institute, Singapore;
Investigative Ophthalmology & Visual Science March 2012, Vol.53, 1592. doi:https://doi.org/10.1167/iovs.12-9693
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Louis Tong, Andrea Petznick; Correlation between Tear Matrix Metalloproteinases and the Schirmer's Test. Invest. Ophthalmol. Vis. Sci. 2012;53(3):1592. https://doi.org/10.1167/iovs.12-9693.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
We read with interest the article by VanDerMeid et al. 1 The authors found that tear proteins such as MMP-9 correlate with Schirmer test values. However, they did not mention whether the correlation remains after adjustment for the effect of age, a determination that is critical for the interpretation of these data. An analysis of the authors' data in their Table 1 shows that the age of the participants correlated inversely with the Schirmer values in the left eye (r = −0.415; P = 0.025), but not in the right. 
It has been reported that age correlates with MMP-9 concentration (Markoulli M, et al. IOVS 2010;51:ARVO E-Abstract 4186) in tears collected before sleep (r = 0.46; P = 0.022). This finding suggests that the association reported between MMPs such as MMP-9 and the Schirmer test results is confounded by age. 
Footnotes
 Supported by National Medical Research Council Singapore Grants NMRC/1206/2009, NMRC/CSA/013/2009, NMRC/TCR/002-SERI/2008, and NMRC/CG/SERI/2010.
References
VanDerMeid KR Su SP Ward KW Zhang J-Z . Correlation of tear inflammatory cytokines and matrix metalloproteinases with four dry eye diagnostic tests. Invest Ophthalmol Vis Sci. 2012;53:1512–1518. [CrossRef] [PubMed]
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×