Abstract
Purpose :
To explore the clinical utilities of tear test of lymphotoxin alpha (LTA) in assessment of patients with dry eye disease(DED) and its association with DED severity, in particular in the conjunctiva and ocular surface microenvironment.
Methods :
In this study, 75 patients with DED were evaluated at baseline and after using diquafosole eye drops. The list of clinical exames conducted included: OSDI questionnaire, measurement of alpha-lymphotoxin (LTA) concentration in 2.2 uL of tear fluid, tear break-up time (BUT), corneal fluorescein staining (CFS), conjunctival lissamine green staining (CLGS), conjunctival impression cytology (IC), Schirmer's test (SS).
Results :
Strong correlation was observed between tear LTA concentration with CLGS scores (R=-0.716, p<0.001), and with IC Nelson’s grades (R=-0.571, p<0.001); good positive correlation between tear LTA concentration with conjunctival goblet cell counts (R=0.520, p<0.001), and to a less extent positive correlation with TBUT (R=0.387, p<0.001). DED patients were devided into two groups: mild and severe based on Nelson score from conjunctival impression cytology level. Differences in LTA concentrations were observed between the groups. With ROC curve analysis, the threshold tear LTA concentration for distinguishing two groups of DED: 0.11 ng/mL (LTA ≥0.11 for mild group and LTA<0.11 for severe group). The group with LTA levels ≥0.11 ng/mL had significantly lower degrees of conjunctival staining (1.69±0.93) compared to the other group (3.40±1.21, P<0.001). LTA ≥0.11 ng/mL group had significantly higher level of conjunctival goblet cell counts (147.80±123.26) and TBUT (5.00±1.81) than those in the LTA <0.11 group (53.63±50.63, P<0.001; 3.80±2.09, P=0.01). After using diquafosole sodium eye drops, LTA<0.11 group exhibited a superior therapeutic response compared to the other group.
Conclusions :
The concentration of tear-fluid LTA was highly correlated with severity in conjunctival pathology: conjunctival staining scores, impression cytology Nelson grading, conjunctival goblet cell density. Patients with lower LTA concentrations exhibited more severity in conjunctiva. Our study proposes that tear-fluid LTA concentration indicates the conjunctival microenvironment in dry eye patients. Tear fluid LTA concentration detection presents a non-invasive and swift technique to evaluate the conjunctival microenvironment in patients with DED.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.