[Anatomical structure and morphometric parameters of the distal segment of the lacrimal drainage system].

The article analyzes the literature data concerning the anatomical structure of the tear ducts with a focus on morphometric studies of individual structures. It is noted that, despite the high information content of cadaveric studies, most of the information to date has been obtained with the use of intravital radiation visualization methods. It is shown that the lacrimal drainage system has age, gender, and racial characteristics. Most studies focus on features of the bone nasolacrimal canal, while there is a relative shortage of research devoted to soft-tissue nasolacrimal duct. The analysis showed that most of the studies are devoted to particular morphometric indicators, which makes it difficult to obtain a complete objective picture of the size of the tear duct. Information about its volume can be found only in a couple of studies. The numerical values of the obtained data vary, which can be explained by a different approach to the selection of research subjects, sample sizes, anatomical criteria and the calculation method of morphometric parameters. There are only a few studies on morphometric parameters of the nasolacrimal duct in healthy humans, which is extremely important for determining the pathogenesis of disorders of the patency of the lacrimal drainage system.