The Radiology of the Lacrimal System

Abstract

Over 200 out of 400 cases of epiphora were examined by a new approach to routine radiography of the lacrimal systems using an original arrangement of apparatus for macro-radiography. This method enhances the value of the examination. The levels of obstruction of the lacrimal systems are illustrated, analysed and classified into 22% high level; 63% middle level; 15% low level. The state of completeness of these obstructions at the different levels is determined. The commonest level of complete obstruction is shown to be in the region of the neck of the sac and not, as generally accepted, at the bony rim of the lacrimal canal or in the canal itself. The cause of this obstruction is found by macro-radiographs and dissection of the cadaver to be due to the nature of the split fascia of the orbicularis muscle at this level. The frequency of epiphora in severe middle third fractures of the face is determined as 12%. This rarity of epiphora is due to the direction of the fracture lines. The state of the lacrimal systems under these conditions is shown to be no different than when obstructed from other causes, and various states of obstruction are illustrated. The appearance of the normal dacryocystogram in the living subject and in the cadaver are described. The radiological anatomy is described and illustrated diagramatically. The indications of abnormality are tabulated.