Stahl Ulrike, Willcox Mark, Stapleton Fiona
Vision Cooperative Research Centre, Sydney, Australia School of Optometry and Vision Sciences, University of New South Wales, Sydney, Australia.
Clin Exp Optom. 2012 Jan;95(1):3-11. doi: 10.1111/j.1444-0938.2011.00634.x. Epub 2011 Oct 25.
The tear film is a nourishing, lubricating and protecting layer that bathes the ocular surface. It is continuously replenished through cycles of production and elimination via evaporation, absorption and drainage. These processes are often referred to as tear film dynamics. Osmolality is an objective clinical measurement that provides insight into the balance of these complex tear film dynamics. Balanced tear production and elimination is vital for tear film integrity, stability and normal osmolality. Imbalances cause alterations of the tear film structure and composition, ultimately leading to tear film instability and measurable tear film hyperosmolality. Elevated tear film osmolality is considered a core mechanism in dry eye, forming the basis of dry eye symptoms and leading to ocular surface damage. Despite its immense potential in the diagnosis of dry eye, tear film osmolality is not commonly assessed. This review will focus on the current knowledge of tear film dynamics and tear film osmolality.
泪膜是一层滋养、润滑和保护的薄膜，覆盖在眼表。它通过蒸发、吸收和引流等产生与消除的循环过程不断得到补充。这些过程通常被称为泪膜动力学。渗透压是一种客观的临床测量指标，有助于深入了解这些复杂的泪膜动力学平衡。泪液的产生和消除达到平衡对于泪膜的完整性、稳定性和正常渗透压至关重要。失衡会导致泪膜结构和成分的改变，最终导致泪膜不稳定和可测量的泪膜高渗。泪膜渗透压升高被认为是干眼的核心机制，是干眼症状的基础，并会导致眼表损伤。尽管泪膜渗透压在干眼诊断中具有巨大潜力，但目前并不常进行评估。本综述将聚焦于泪膜动力学和泪膜渗透压的现有知识。
