Background: From the 1990's onward, it has been possible to assess changes in the lacrimal duct by direct, minimally invasive diagnostic inspection with the aid of miniaturized endoscopes originally used in gastroduodenal surgery. It has been shown in this way that mechanical lacrimal duct stenosis often develops gradually as the result of recurrent chronic inflammation. Absolute stenoses are often located at a single point rather than extending over a longer segment of the duct.
Methods: Advances in lacrimal duct surgery are presented through a selective review of the relevant literature.
Results: Roughly 70% to 80% of all mechanical stenoses of the lacrimal duct can be reopened during endoscopic surgery with the use of a laser or a miniaturized drill.
Conclusion: With the methods described here, it is now possible for the first time to perform surgery that obviates the need for a bypass procedure and maintains or restores the normal physiological function of the lacrimal system.