Movement of internal canalicular orifice in association with blinking: direct observation after dacryocystorhinostomy

To examine movement of the internal canalicular orifice with blinking and lacrimal drainage under endonasal endoscopic observation after dacryocystorhinostomy.

Observational anatomic study.

Twenty internal canalicular orifices (right 9, left 11) from 15 patients (age range: 44-77 years) who underwent endoscopic endonasal dacryocystorhinostomy were prospectively examined. The patients sat on a chair with the chin projected slightly upward while digital images were taken. After examining the movement of the internal canalicular orifice with blinking, the patient's eye was stained with fluorescein dye, and diffusion from the orifice was examined with blinking.

The internal canalicular orifice closed during eyelid opening, although always incompletely. In eyelid closing, the orifice opened, and was pulled laterally without folds. All 20 internal canalicular orifices formed a diverticulum. Three specimens illustrated the upper and lower canalicular ends emptying into the diverticulum. The closing of these canalicular ends was always incomplete. Movement of the internal canalicular orifice was slight during normal blinking, but forced blinking resulted in more movement. Movement of the lacrimal sac wall was slight. During the first few seconds without blinking, no fluorescein dye flowed from the orifice. After several blinks, fluorescein dye flowed out slowly from the orifice, and increased in volume with more blinking. The fluorescein dye traveled inferiorly by gravity. A forced blinking was related to more dye inflow.

The internal canalicular orifice incompletely closed during eyelid opening, but this orifice largely opened during eyelid closing, with a slow gravitational inflow of lacrimal fluid.