泪液渗透压在干眼发病机制中的作用及诊疗进展

干眼是一种以眼表稳态丧失，泪膜不稳定性增加为特征的多因素疾病，伴有眼干涩、异物感、灼烧感、眼红、疼痛、畏光、流泪、眼疲劳、视力下降、分泌物增多、对外界刺激敏感等眼部症状，其病理生理机制主要是泪膜不稳定、泪液渗透压(tear osmolarity, Tosm)升高、眼表炎症和损伤及神经感觉异常。Tosm是维持泪膜稳定性和眼表舒适度的重要因素。Tosm升高可造成干眼患者眼部不适、角膜上皮损伤、杯状细胞丢失及眼部炎症反应，炎症反应可进一步降低泪膜稳定性和增加Tosm,使干眼陷入恶性循环。为了更全面地了解泪液高渗(tear hyperosmolarity, THO)与干眼的关系，本文将从病理生理学方面，重点讨论THO在干眼发病机制、干眼诊断、干眼严重程度分级中的作用，及其针对性治疗。

Role of tear osmolarity in the pathogenesis of dry eyes and the progress of diagnosis and treatment

Dry eye is a multifactorial disease characterized by loss of ocular surface homeostasis and increased tear film instability, accompanied by ocular symptoms such as ocular dryness, foreign body sensation, burning sensation, eye redness, pain, photophobia, tearing, eye fatigue, decreased visual acuity, increased secretion, and sensitivity to external stimuli. Its pathophysiological mechanisms are mainly tear film instability, elevated tear osmolarity(Tosm), ocular surface inflammation and injury, and neurosensory abnormalities. Tosm is an important factor in maintaining tear film stability and ocular surface comfort. Elevated Tosm can cause ocular discomfort, corneal epithelial damage, loss of goblet cells and ocular inflammatory response in dry eye patients, and the inflammatory response can further reduce tear film stability and increase Tosm, which puts dry eye in a vicious cycle. In order to have a more comprehensive understanding of the relationship between tear hyperosmolarity(THO)and dry eye, this article will focus on the role of THO in the pathogenesis, diagnosis, severity classification and targeted treatment of dry eyes from the aspect of pathophysiology.