Evaluation of the relationship between thyroid functions and dry eye symptoms in patients with Hashimoto thyroiditis

Abstract

Purpose: Dry eye is the most common symptom of thyroid-associated ophthalmopathy in Hashimoto thyroiditis. Ocular surface inflammation, tear hyperosmolarity and overproduction of inflammatory cytokines are responsible for the development of this process. In this study, we aimed to investigate the relationship between thyroid functions and dry eye symptoms in patients with Hashimoto thyroiditis. Materials and Methods: The patients, diagnosed with Hashimoto thyroiditis (n:125), were included in this monocenter cross-sectional study. The study population was divided into three groups: euthyroidism (Group–1, n:48), subclinical hypothyroidism (Group–2, n:38) and overt hypothyroidism (Group–3, n:39). The groups were compared based on the presence of dry eye syndrome, Schirmer tests, OSDI scores of patients with dry eye diagnosis and tear break-up time. The results were analyzed with ANOVA and Spearman’s correlation test. Results: No significant difference was found in the frequency of dry eye syndrome between the groups (p = 0.1). There was no difference in the Schirmer scores and tear break-up time measurements (p = 0.6 and 0.2). The severity of OSDI scores was significantly milder in the patients with dry eye diagnosis, in the euthyroid group (p = 0.03). Serum fT3 levels positively correlated with tear break up time measurements (p = 0.004, r = 0.302) and negatively correlated with presence of dry eye syndrome (p = 0.03, r = –0.981). Discussion: Although dry eye symptoms tend to be milder in euthyroid patients, the frequency of dry eye syndrome is similar in patients with Hashimoto thyroiditis, independent of thyroid function status.