甲状腺相关性眼病的眼表损害

Ocular surface damage of thyroid-associated ophthalmopathy

与自身免疫相关的甲状腺相关性眼病(thyroid-associated ophthalmopathy,TAO),是由于多因素紊乱引起眶周及眶内眼部组织炎性浸润的疾病,发病机制尚未阐明。TAO的眼部损害累及范围广,引起的眼表损害对视觉功能影响明显。TAO引起的睑裂增大、睑板腺病变、睑板腺功能障碍、泪膜脂质层的减少导致泪液蒸发过强,泪液高渗透压改变,从而诱发或加重眼表炎症。泪液中炎性因子的异常表达及主副泪腺病变,水液层减少引起泪液渗透压进一步升高。炎症的恶性循环引起角结膜屏障受损,角膜神经纤维密度降低及角膜敏感性下降等病变。TAO患者角膜生物力学性能改变,形变能力下降影响了真实眼压值的测量。TAO还伴随眶内组织增生扩张,患者眶压升高,导致血液循环的障碍,眼表的营养供应障碍,眼表正常生理功能包括结膜杯状细胞分泌黏蛋白等受影响。TAO导致的眼表损害引起一系列严重眼部不适及容貌毁损,威胁患者身心健康。

Thyroid-associated ophthalmopathy associated with autoimmunity is a disease of inflammatory infiltration of periorbital and intraorbital ocular tissue caused by multi-factor disorders,but the pathogenesis has not been elucidated.The ocular damage caused by TAO has a wide range of involvement,and the ocular surface damage has a significant impact on visual function.The enlargement of palpebral fissure,the lesion of meibomian gland,the dysfunction of meibomian gland and the decrease of lipid layer of tear film caused by TAO lead to excessive evaporation of tear and the change of high osmotic pressure of tear,which induces or aggravates ocular surface inflammation.The abnormal expression of inflammatory factors in tears and the pathological changes of main and accessory lacrimal glands,and the decrease of water layer led to the further increase of tear osmotic pressure.The vicious circle of inflammation causes the damage of keratoconjunctival barrier,the decrease of corneal nerve fiber density and the decrease of corneal sensitivity.The changes of corneal biomechanical properties and the decrease of deformability in patients with TAO affected the measurement of intraocular pressure.TAO is also accompanied by orbital tissue hyperplasia and expansion,and the orbital pressure increases in patients,which lead to the disturbance of blood circulation.The nutritional supply of the ocular surface is impaired,and the normal physiological function of the ocular surface including the secretion of mucin by conjunctival goblet cells is affected.Ocular surface damage caused by TAO causes a series of serious eye discomfort and facial damage,which threatens the physical and mental health of patients.