Risk Factors for Structural Changes in Meibomian Gland in Thyroid Eye Disease

Abstract

Purpose: To investigate the effect of clinical activity score (CAS) and thyroid stimulating hormone receptor autoantibody (TSHR autoantibody) on structural changes in Meibomian gland in patients with thyroid eye disease (TED). Methods: From March 2015 to February 2016, retrospective and cross-sectional studies were performed on patients diagnosed with TED. We investigated thyroid function, TSHR autoantibody (thyrotopin-binding inhibitor immunoglobulin [ TBII] assay) status, duration of TED, CAS, and analyzed the Meibomian gland structure using a Lipiview inferometer((R)) (TearScience Inc., Morrisville, NC, USA). We evaluated the degree of meibum expression (ME) and the tear film breakdown time by slit lamp microscopy. Results: A total of 37 patients (13 males and 24 females) with TED were included in the study, and the mean age was 43.8 +/- 13.3 years. At the time of the study, 24 patients (64.9%) had hyperthyroidism, five patients (13.5%) had hypothyroidism, and eight patients (21.6%) had normal functioning. The mean CAS was 1.86 +/- 1.74 (0-7), nine patients (24.3%) were in the active group with >= 3 points of CAS, and 28 patients (75.7%) were in the inactive group with < 3 points of CAS. The meiboscore was 1.05 +/- 0.82 in the upper eyelid, and 0.76 +/- 0.76 in the lower eyelid, with a significantly higher upper eyelid (p = 0.001). The mean value of the TBII was 6.11 +/- 11.35 IU/L. Sixteen patients (43.2%) had TBII above the normal 1.5 value, and 21 patients (56.8%) had a normal TBII. The meiboscore of the upper eyelid was significantly higher when the TBII was higher than normal (p = 0.045). CAS (r = 0.356, p = 0.030), ME (r = 0.379, p = 0.021), and TBII (r = 0.334, p = 0.044) were significantly associated with the meiboscore in the upper eyelid. Using multiple regression analyses, CAS (p = 0.010) and TBII (p = 0.011) were factors affecting the upper eyelid meiboscore, and CAS (p = 0.015) and TBII (p = 0.038) were factors affecting the lower eyelid meiboscore. Conclusions: The structural loss of Meibomian glands in patients with TED was greater in the upper eyelid than lower eyelid, and CAS and TSHR autoantibody had an effect on the structural loss of the Meibomian gland.