[Modern, minimally invasive surgery of the lacrimal duct system].

Dacryorrhea is a relatively common but often difficult problem from a differential diagnostic aspect. The most important symptom of dysfunction of lacrimal drainage is called epiphora. Due to the enhancements and miniaturization of endoscopes originally used in gastroduodenal surgery, since the 1990s it is possible to check the anatomical structure and the pathological changes of the lacrimal drainage system, which is only 1 mm in diameter. Mechanical stenosis is often caused by recurrent chronic inflammation. Complete stenosis is usually only dot-like and seldom occurs over a long distance. Shortly after the development of tools for microendoscopic diagnosis, therapeutic techniques were established, such as laser dacryoplasty (LDP) for which a laser is used and microdrill dacryoplasty (MDP) for which a drill is used. These procedures allow for the first time the whole physiology of the lacrimal drainage system to be preserved despite surgical intervention.