目的: 探讨合并甲状腺功能减退(hypothyroidism, HT)对原发性干燥综合征相关性干眼(primary Sjögren’ s syndrome related dry eye, pSS-DED)患者眼表状态的影响。方法: 采用横断面研究，选择2020年12月—2021年6月在北京大学第三医院眼科干眼门诊就诊的pSS-DED患者36例，其中合并HT的pSS-DED患者12例，并纳入同时期就诊的单纯干眼症(dry eye disease, DED)患者24例作为对照组。所有患者填写眼表疾病指数(ocular surface disease index, OSDI)问卷，并进行泪膜破裂时间(tear film break-up time, BUT)、泪液分泌Schirmer试验、泪河高度、角/结膜荧光素染色、睑板腺分泌能力、睑酯性状评估，以及共聚焦显微镜检查。结果: (1) 较pSS-DED及单纯DED患者，合并HT后pSS-DED患者的平均BUT[(2.7±0.8) s]、Schirmer试验结果[(4.9±4.8) mm]以及泪河高度[(0.13±0.03) mm]更低，差异具有统计学意义(F=12.43，P < 0.01；F=6.96，P < 0.01；F=3.31, P < 0.05)。(2)合并HT后pSS-DED患者的睑板腺分泌能力与睑酯性状评分较DED与pSS-DED患者多集中于高分区，3组患者的睑板腺分泌能力(χ²=10.72，P < 0.05)及睑酯性状评估分数分布(χ²=8.34，P < 0.05)差异具有统计学意义。(3)pSS-DED+HT患者血清总甲状腺素、血清游离甲状腺素水平与其BUT(r=0.60；0.60)、Schirmer试验(r=0.64；0.66)，以及泪河高度(r=0.61；0.62)正相关(P < 0.05；P < 0.05)，与睑板腺分泌能力无关；未发现促甲状腺激素、抗甲状腺球蛋白抗体、甲状腺过氧化物酶抗体与眼表状态存在明显相关性。(4)相较pSS-DED，合并HT后患者基底下神经丛纤维密度降低(t=2.06，P < 0.05)，曲率评分增加(t=2.13，P < 0.05)。结论: 合并HT的pSS-DED患者较pSS-DED以及DED患者的眼表状况更差，主要表现为泪液分泌减少、泪膜稳定性下降、睑板腺分泌功能降低、睑酯性状变差、基底下神经丛纤维密度降低与曲率增加，其机制可能与甲状腺激素分泌减少有关。

Objective: To explore the effect of hypothyroidism (HT) on the ocular surface status of patients with primary Sjögren's syndrome-related dry eye (pSS-DED). Methods: The cross-sectional study included 36 patients with pSS-DED who were treated at the dry eye clinic of Peking University Third Hospital from December 2020 to June 2021, of whom 12 were pSS-DED patients combined with HT. In the same period, 24 patients with simple dry eye disease (DED) were served as a control group. All the patients filled out the Ocular Surface Disease Index (OSDI) questionnaire, and performed tear film break-up time (BUT), Schirmer test, tear meniscus height, corneal/conjunctival fluorescein staining, meibomian gland secretion capacity, meibum evaluation and confocal microscope examination. Results: (1) Compared with pSS-DED and simple DED patients, pSS-DED +HT patients had lower average BUT [(2.7±0.8) s], Schirmer test [(4.9±4.8) mm] and tear meniscus height [(0.13±0.03) mm], and the difference was statistically significant (F=12.43, P < 0.01; F=6.96, P < 0.01; F=3.31, P < 0.05). (2) Compared with DED and pSS-DED patients, the meibomian gland secretion capacity and meibomian trait scores of pSS-DED+HT patients were mainly distributed in the high division. There were statistically significant differences in the distribution of secretion capacity of meibomian glands (χ²=10.72, P < 0.05) and meibomian trait assessment scores (χ²=8.34, P < 0.05) among the three groups. (3) Serum total thyroxine and serum free thyroxine levels in the pSS-DED+HT patients showed positive correlation (P < 0.05, P < 0.05) with their BUT (r=0.60, 0.60), Schirmer's test (r=0.64, 0.66) and tear river height (r=0.61, 0.62), independent of lid gland secretory capacity; no significant correlation was found between thyroid-stimulating hormone, anti-thyroglobulin antibody and lid gland secretory capacity. Thyroid hormone, anti-thyroglobulin antibody, and thyroid peroxidase antibody were not found to be significantly correlated with ocular surface status. (4) Compared with pSS-DED, the fiber density of the subbasal nerve plexus in pSS-DED+HT group decreased (t=2.06, P < 0.05), and the curvature score increased (t=2.13, P < 0.05). Conclusion: The ocular surface condition of pSS-DED patients with HT is worse than that of pSS-DED and DED patients. The main manifestations are that tear secretion, tear film stability, secretory function of the meibomian glands, meibum trait and fiber density of the subbasal nerve plexus decrease while the curvature increases. The mechanism might be related to the decrease in thyroid hormone production.