Busse H, Müller K M, Osmers F
Rofo. 1977 Aug;127(2):154-8. doi: 10.1055/s-0029-1230673.
This position and relationship to the facial skeleton of the tear ducts in neonates were studies during 25 post mortem examinations by injection of contrast material into them and the findings were correlated with microscopic appearances. This produced the following results: in more than 50% cases there was unilateral or bilateral narrowing of the distal end of the duct due to persistence of Hasner's membrane. The ration of length of the tear duct and the ductus in neonates is 1:2 (adults 1:3). The proximal portions of the ducts between the saccus and the ductus show multiple transverse mucosal folds. There are several more or less acute curves in both planes. The examination indicates that in the treatment of neonatal dachryostenosis it is necessary to use a combination of dilatation and pressure injections.