Meibomian glands dropout in patients with inactive thyroid related orbitopathy

PURPOSE: To evaluate the structure and function of meibomian glands in patients with thyroid related orbitopathy (TRO) compared with age- and sex-matched controls without TRO. METHODS: This cross-sectional study included 106 eyes of 53 patients with TRO and 106 eyes of 53 age- and sex-matched controls without TRO. Patients with TRO were assessed for thyroid hormone status, activity and severity of TRO. All participants completed OSDI questionnaires. Their meibomian glands’ structure and function were assessed, including the area of meibomian gland dropout, lipid layer thickness (LLT), meibum expressibility and quality scores, tear break-up time (TBUT), corneal and conjunctival staining scores. A generalized estimating equation (GEE) was used to compare between the two groups. The correlations between the area of meibomian gland dropout with symptoms and signs of TRO were evaluated using GEE and Spearman correlation. RESULTS: All patients with TRO had inactive status. The mean area of meibomian gland dropout was higher in the TRO group (34.5±11.2%) compared with that of controls (30.1±10.7%, P = 0.03). Both mean meibum quality (TRO, 1.6±0.7; Controls, 2.0 ±0.5) and expressibility (TRO, 1.5 ±0.7; Controls, 1.7 ±0.6) scores were slightly better in the TRO group compared with those of controls (P = 0.01). There was no significant difference in OSDI, corneal and conjunctival staining, TBUT and LLT. The area of meibomian gland dropout in patients with TRO was correlated with euthyroid status (P<0.05) and lagophthalmos (P = 0.03). CONCLUSIONS: Patients with inactive TRO showed significantly higher meibomian gland dropout compared with that of age- and sex-matched controls without TRO.