Korean J Ophthalmol.  2020 Jun;34(3):179-186. 10.3341/kjo.2019.0145.

Tear Osmolarity and Matrix Metallopeptidase-9 in Dry Eye Associated with Sjögren’s Syndrome

• Kook KY
• Jin R
• Li L
• Yoon HJ
• Yoon KC

• KMID: 2502645
• DOI: http://doi.org/10.3341/kjo.2019.0145

Abstract

Purpose
To evaluate the correlations between tear osmolarity and matrix metallopeptidase-9 (MMP-9) and dry eye (DE) indices in patients with DE associated with Sjögren’s syndrome (SS).
Methods
Sixty-three patients with DE associated with SS who underwent tear analysis were included. DE tests performed were ocular surface disease index, tear break-up time, Schirmer’s test, ocular staining score, and tear osmolarity and MMP-9 tests. Correlations between tear osmolarity and DE indices, differences between patients with abnormal and normal tear osmolarity, and those between positive and negative MMP-9 patients were analyzed. Patients were classified into four groups according to tear osmolarity and MMP-9 results, and between-group differences were analyzed (group 1: abnormal tear osmolarity, MMP-9 positive; group 2: abnormal tear osmolarity, MMP-9 negative; group 3: normal tear osmolarity, MMP-9 positive; group 4: normal tear osmolarity, MMP-9 negative).
Results
Mean age of patients was 54.2 ± 13.9 years, and 96.2% were female. Thirty-five patients had abnormal tear osmolarity and 40 patients were MMP-9 positive. DE indices differed between groups with abnormal and normal tear osmolarity (p < 0.01), but not between positive and negative MMP-9 groups. There were 22 patients in group 1, 13 in group 2, 18 in group 3, and 10 in group 4. Compared to group 4, tear break-up time was shorter in groups 1 (p < 0.01) and 2 (p = 0.02). Schirmer’s test values in group 1 were lower than those in group 4 (p = 0.03). Ocular staining score was higher in groups 1 (p < 0.01) and 2 (p < 0.05) than in group 4.
Conclusions
Tear osmolarity was correlated with ocular surface indices in DE associated with SS. Combination of tear osmolarity and MMP-9 test results may be helpful to determine the severity of DE associated with SS.

Keyword

Dry eye syndromes; Matrix metallopeptidase-9; Sjogren’s syndrome; Tear osmolarity