Paulsen F, Thale A, Schaudig U
Anatomisches Institut, Christian-Albrechts-Universität zu Kiel, Olshausenstrasse 40, 24098 Kiel.
Ophthalmologe. 2002 Jul;99(7):566-74. doi: 10.1007/s00347-001-0585-6.
The knowledge regarding the pathogenesis, diagnosis, and treatment of dry eye has made large advances in recent years. However, many questions are still unanswered. Although the nasolacrimal ducts are part of the tear system they have been paid nearly no attention regarding dry eye.
The present knowledge about the nasolacrimal ducts is presented and discussed in a context with dry eye. A PubMED search was conducted for articles published from 1966 to the present; in addition, review articles as well as book chapters were considered and discussions with investigators in the field were performed.
As a draining and secretory system, the nasolacrimal ducts play a role in tear transport and non-specific immune defense. Moreover, components of tear fluid are absorbed in the nasolacrimal passage and are transported into a vascular system that surrounds the nasolacrimal sac and nasolacrimal duct. This system is comparable to a cavernous body and it is connected to the blood vessels of the outer eye. Also it is subject to vegetative control. Organized mucosa-associated lymphoid tissue (MALT) is present in the nasolacrimal ducts displaying the cytomorphological and immunophenotypic features of MALT.
The normally constant absorption of tear fluid components into the blood vessels of the surrounding cavernous body that are connected to the blood vessels of the outer eye, could be a feedback signal for tear fluid production, which comes to a halt if these tear components are not absorbed. Thus, dry eye could be initiated. Defective stimulation of tear duct-associated lymphoid tissue (TALT) could result in abnormal immune deviation at the ocular surface leading to an autoimmunological response that causes dry eye pathology.
近年来，关于干眼的发病机制、诊断和治疗的知识取得了巨大进展。然而，许多问题仍未得到解答。尽管鼻泪管是泪液系统的一部分，但在干眼方面几乎未受到关注。
本文在干眼的背景下介绍并讨论了关于鼻泪管的现有知识。对1966年至今发表的文章进行了PubMed检索；此外，还考虑了综述文章和书籍章节，并与该领域的研究人员进行了讨论。
作为一个引流和分泌系统，鼻泪管在泪液运输和非特异性免疫防御中发挥作用。此外，泪液成分在鼻泪通道中被吸收，并被输送到围绕鼻泪囊和鼻泪管的血管系统中。这个系统类似于海绵体，与眼外血管相连，并且受自主神经控制。鼻泪管中存在有组织的黏膜相关淋巴组织（MALT），表现出MALT的细胞形态学和免疫表型特征。
泪液成分正常持续地被吸收到与眼外血管相连的周围海绵体血管中，这可能是泪液分泌的一个反馈信号，如果这些泪液成分不被吸收，泪液分泌就会停止。因此，可能引发干眼。泪道相关淋巴组织（TALT）刺激缺陷可能导致眼表免疫偏离异常，从而引发自身免疫反应，导致干眼病理改变。
