Conjunctival staining scores offer useful indicator of ocular surface inflammation

This study investigated the expression levels of inflammatory cytokines in the conjunctival epithelium and correlations with clinical parameters in dry eye disease (DED).

Study design

This cross-sectional case-control study evaluated 28 patients with primary Sjogren’s syndrome (SS) DED, 28 with non-SS DED and 10 controls. All patients were female. Messenger ribonucleic acid (mRNA) expression of inflammatory cytokines involved in dry eye were correlated with dry eye parameters such as ocular surface disease index score (OSDI), Schirmer I, tear film break-up time (TBUT) and corneal and conjunctival staining.

Outcomes

Dry eye patients had significantly higher cytokine gene expression in the conjunctival epithelium than controls. In addition, certain cytokines (TNF-alpha, IL-1beta, IL-6 and IL-7) were higher in patients with SS DED compared with the non-SS DED group. Scores of conjunctival staining with lissamine green correlated with expression of 3 cytokines in both groups; this correlation was higher in the SS DED group than in the non-SS DED group.

Limitations

Patient selection was specific (e.g., excluding patients taking systemic medications that affect dry eye, contact lenses wearers. those using any DED treatment aside from artificial tears within 3 months of the study or those with lid abnormalities or a history of ocular surgery within the past 6 months). This strengthened the study findings but may not support extrapolation to the general patient population. Additionally, tear osmolarity was not taken into consideration for this study.

Clinical significance

These findings suggest that conjunctival staining scores may be useful to measure ocular surface inflammation in patients with DED, including those with SS.