Abstract
Purpose :
This study aimed to measure and compare the LTA levels in tears from dry eye disease (DED) patients with systemic immune disease (ID) and DED without, and to examine the role and clinical value of LTA in early diagnosis of DED associated with ID. LTA (also known as LTa3), the secreted soluble homotrimeric form of Lymphotoxin-alpha, is a cytokine that performs a variety of important roles in immune regulation.
Methods :
An observational study consecutively enrolled moderate to severe DED patients with or without Sjogren’s syndrome (SS) or other ID at the Xi’an People’s Hospital (Xi'an, China) from March to July 2022. The Ocular Surface Disease Index (OSDI) and Ocular discomfort score (ODS), conjunctival hyperemia, eyelid margin morphology assessment (EMMA), Schirmer’s test (STT), non-invasive tear breakup time (NITBUT), tear meniscus height (NITMH), corneal fluorescein staining (CFS), and conjunctival lissamine green staining (LGS) were also conducted. The LTA levels were measured with a Point-of-Care (POC) LTA test kit on-site and compared across different DED groups. Correlations with DED clinical parameters were also examined.
Results :
This study enrolled a total of 80 patients, 44 of which had SS or other ID and 36 of which did not. The DED patients with SS or ID exhibited significantly lower STT (3.61 (95% CI: 2.53-4.70), 7.58 (5.45-9.72), P<0.001), shorter NITBUT (4.57 (3.59-5.54), 9.06 (7.56-10.57) p<0.001), more conjunctival hyperemia (p<0.001), higher EMMA score (P<0.001), higher CFS (p<0.001) and LGSC (P<0.001), worse ODS (p<0.05), and worse visual acuity (p<0.01). Importantly, in the DED group with SS or ID, LTA levels in tears were significantly lower (169.82 vs. 331.13 pg/ml, p<0.01) than the DED group without. Moreover, the LTA level was significantly negatively correlated with CFS (correlation coefficient (r): -0.447, P<0.001) and EMMA score (r: -0.317, P=0.01).
Conclusions :
Previously tear LTA was found reduced in DED compared with normal. Here LTA levels in DED with SS or ID were remarkably lower than in DED patients without. The level of LTA was significantly inversely correlated with the severity of ocular surface damage. Thus, a POC LTA test may have clinical value as an indicator to reflect DED severity and serve as an early diagnostic marker for SS or ID-associated dry eye.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.