Clinical characteristics of dry eye patients with thyroid disorders: a cross-sectional study

To characterize the clinical findings in dry eye disease (DED) patients with thyroid disorders and explore their associations with DED symptoms and signs.

In this retrospective cross-sectional chart review study, 99 patients who were diagnosed as DED and subjected to thyroid function screening were included. Corneal fluorescein staining (CFS), Schirmer 1 test (S1T), tear meniscus height (TMH), the first noninvasive breakup time (NIBUT-first), the average noninvasive breakup time (NIBUT-avg), and meibomian gland (MG) dropout ratio were tested and their correlations with thyroid function were analyzed.

Overall, the average age and gender distribution of DED patients with or without thyroid disorders were similar (p = 0.391 and 0.804). DED patients with thyroid disorders had shorter NIBUT-first(p < 0.001) and NIBUT-avg( p = 0.0042), and higher MG dropout ratio (p = 0.001). Among thyroid function assessments, elevated levels of anti-thyroid peroxidase antibody (Anti-TPO) and anti-thyroglobulin antibody (Anti-Tg) had significant correlation with reduced NIBUT and increased MG dropout ratio. When either NIBUT-first or MG dropout ratio was used as a predicting factor for thyroid disorders, ROC curve demonstrated a cut-off value of 5.255(NIBUT-first AUC 0.770, sensitivity 85.7%, specificity 58.8%, p < 0.001) and 0.229 (MG dropout ratio AUC 0.784, sensitivity 70.6%, specificity 79.6%, p < 0.001). When combining them together, an AUC area of 0.841(sensitivity 88.2%, specificity 66.2%, p < 0.001) was reached.

Shorter NIBUT and higher MG dropout ratio correlated with abnormally elevated levels of Anti-TPO and Anti-Tg in DED patients. A combination of NIBUT and MG dropout assessment may have diagnostic potential as a predictive biomarker of possible thyroid disorders.