Hashimoto's Thyroiditis and Dry Eye Disease

Area of Science:

• Ophthalmology
• Immunology
• Endocrinology

Background:

• Hashimoto's thyroiditis (HT) is an autoimmune thyroid disease.
• Autoimmune processes in HT can affect other organs, including the lacrimal gland.
• Dry eye disease (DED) is a potential ocular manifestation of HT.

Purpose of the Study:

• To analyze tear biomarkers in patients with Hashimoto's thyroiditis.
• To explore correlations between tear biomarkers and clinical ocular parameters in HT patients.
• To investigate the specific role of certain cytokines and enzymes in HT-associated DED.

Main Methods:

• Comparative study involving 150 participants: HT group (N=50), non-HT DED group (N=50), and healthy controls (N=50).
• Ocular surface assessments included OSDI, TBUT, LFC, Schirmer test, and staining (lissamine green, fluorescein).
• Tear samples analyzed for cytokines (IL-1β, TNF-α, IL-6, IL-8, IL-10, IL-17A) and MMP-9 using ELISA and multiplex immunoassay.

Main Results:

• DED prevalence exceeded 50% in the HT group, with severe symptoms in 48.15% of DED HT subgroup.
• Significantly elevated IL-6 levels were found in the DED HT subgroup compared to non-HT DED (p=0.010), suggesting HT specificity.
• Significantly lower IL-10 levels (p=0.008) and higher lissamine green staining and LIPCOF (p<0.001) were observed in the DED HT subgroup.

Conclusions:

• DED is prevalent in euthyroid HT patients, even without thyroid-associated orbitopathy (TAO).
• Elevated tear IL-6 may serve as a specific biomarker for HT-associated DED.
• Lissamine green staining and LIPCOF are valuable for assessing ocular surface status in DED HT patients.