• In human cadaver specimens, a laser fiberoptic was advanced through the canalicular systems to create fistulas between the nasolacrimal sac and nose. A 400- to 600-μm, blunt-tipped quartz fiberoptic was then advanced through the upper and/or lower canaliculus to the medial aspect of the nasolacrimal sac. After 10 to 15 laser pulses (10 W for 0.1 second), a 2.5 × 2.5-mm fistula was created between the lacrimal sac and the nose just anterior and inferior to the middle turbinate. Additional laser pulses can further enlarge the fistula. Endocanalicular laser-assisted dacryocystorhinostomy has potential advantages compared with endonasal laser-assisted dacryocystorhinostomy, including the following: laser energy is directed away from the eye; the technique resembles standard nasolacrimal probing; and nasal endoscopy and instrumentation may prove unnecessary.
Levin PS, StormoGipson DJ. Endocanalicular Laser-Assisted DacryocystorhinostomyAn Anatomic Study. Arch Ophthalmol. 1992;110(10):1488-1490. doi:10.1001/archopht.1992.01080220150037