Hashimoto's Thyroiditis And Dry Eye Disease

This study aimed to evaluate tear biomarkers and assess their correlations with clinical ocular parameters in patients with Hashimoto’s thyroiditis.

This study was conducted at the University Hospital Center Sisters of Mercy, in collaboration with Department of Ophthalmology, Department of Clinical Chemistry, Department of Oncology and Nuclear Medicine, School of Dental Medicine, University of Zagreb, and with Department of Medical Statistics, Epidemiology and Medical Informatics, School of Public Health "Andrija Štampar", School of Medicine, University of Zagreb, Croatia.

A total of 150 participants were categorized into three groups: Hashimoto's thyroiditis, dry eye disease group without Hashimoto's thyroiditis, and healthy group. All participants underwent a comprehensive evaluation for ocular surface, which included the Ocular Surface Disease Index, Tear Break-Up Time, Lid-Parallel Conjunctival Folds, Schirmer test without anesthetic, as well as lissamine green and fluorescein staining. Tear samples were collected and analyzed for cytokine and enzyme levels, using ELISA and multiplex immunoassay techniques. Statistical analyses were performed to compare the groups and examine correlations between biomarkers.

Dry eye disease (DED) was identified in more than half of the study participants, with severe symptoms present in 48.15% of those with Hashimoto’s thyroiditis (HT) and DED. IL-6 levels were significantly higher in the HT-DED subgroup compared to the non-HT DED group (p = 0.010), indicating a potential association with HT-related DED. MMP-9 was elevated in both the HT and non-HT DED groups (p < 0.001), though it did not show specificity for HT (p = 0.059). Additionally, the HT-DED subgroup exhibited significantly lower IL-10 levels (p = 0.008). Lissamine green staining and LIPCOF scores were significantly increased in the HT-DED subgroup (p < 0.001).

Dry eye disease is frequently observed in euthyroid HT patients who do not exhibit signs of TAO. This study emphasizes the potential involvement of IL-6. Lissamine green staining and LIPCOF serve as important diagnostic tools for evaluating the ocular surface in HT-DED patients.