An unconventional view of dacryocystorhinostomy.

Twenty-one dacryocystorhinostomy operations were assessed by nasendoscopy. In fourteen of the 15 successful operations pre-operative radiography had demonstrated a low obstruction in the lacrimal passages. Postoperatively the nasal ostia in this group showed great morphological diversity. In five of the 6 operations which were not clinically successful a high obstruction in the lacrimal passages had been demonstrated pre-operatively. In all cases in this group the nasal ostia were closed. In these 5 cases with an obstruction in the canaliculus communis, minimal or absent flow of tears through the dacryocystorhinostomy may be assumed. The surgical technique was the same in all 21 cases. The high canalicular problem seems to be responsible for the failure of these 5 operations. A notable feature was that nasendoscopy revealed a closed nasal ostium. This suggests that sufficient tearflow through the dacryocystorhinostomy is necessary to keep this open. To what extent the individual variation in tearflow and patency of the canalicular system is responsible for the morphological variation in the nasal ostium, as observed in the clinically successful group, is not yet clear.