research progress of lacrimal drainage system

Lacrimal drainage is the process of drainage tear from eye surface to nasal cavity and its mechanism is complex. It requires not only the coordination of gland and muscle system of eyelid, but also the joint participation of lacrimal secretion system and drainage system. For hundreds of years, the function and mechanism of lacrimal drainage system has been concerned by ophthalmologists. Many representative viewpoints have been put forward and great progress has been made. It has important clinical significance to improve the diagnosis and treatment of lacrimal passage diseases. This paper reviews the anatomical background, mechanism, problems and prospects of lacrimal drainage system.