Anatomical analysis of the human lacrimal drainage pathway under an operating microscope.

Mesoscopic structures of the lacrimal drainage pathway were observed under an operating microscope in six cases of 5 adult cadavers. In all these cases the upper and lower canaliculi fused to form the common canaliculus. Two cases with a large common canaliculus showed large projections of mucosa which reduced the inner space of the common canaliculus. The remaining 4 cases with a small common canaliculus did not show any projections. These findings indicate that the human lacrimal system can function physiologically through a small narrow space of the common canaliculus.