Relative canalicular tear flow as assessed by dacryoscintigraphy.

Studies evaluating the relative importance of the upper and lower canaliculi in tear drainage have been many and varied, and at times the application of the data to clinical situations is difficult. In order to evaluate the relative tear flow in the upper and lower canaliculi and to quantitatively evaluate the different tear flow rates by a physiologic method, we have studied 11 patients using partial canalicular obstructions and dacryoscintigraphy. The authors found no statistical difference in tear flow between the upper and lower canalicular systems. This information has clinical application when deciding whether to repair an isolated canalicular injury.