Lesson Summary

This video covers the anatomy of the nasal lacrimal system, essential for understanding and performing dilation and irrigation (D&I) procedures effectively and safely.

Key anatomical components include:

• Superior and Inferior Puncta: Openings located on the medial sides of the upper and lower eyelids, often referred to as tear ducts in clinical settings.
• Vertical Canaliculi: Short vertical segments (~2 mm) leading from the puncta into the horizontal canaliculi.
• Horizontal Canaliculi: Longer horizontal segments running underneath the skin.
• Common Canaliculus: Junction point where the superior and inferior canaliculi meet; present in most individuals.
• Lacrimal Sac: Large reservoir for tears located in the lacrimal fossa.
• Nasal Lacrimal Duct: Long channel passing through the maxillary bone down to the valve of Hasner.
• Valve of Hasner: Mucosal fold at the inferior meatus opening; this is the most common site of obstruction in infants.

Understanding this anatomy is crucial for proper technique during D&I procedures to avoid complications:

• Apply gentle and correct dilation pressure without puncturing canalicular walls.
• Ensure appropriate placement of the cannula.
• Control syringe pressure to avoid trauma.
• Observe the source of any saline reflux (superior or inferior puncta) to help identify obstruction sites.

In summary, a firm grasp of nasal lacrimal anatomy enables effective, safe, and precise D&I procedures.

Stay tuned for the next video covering clinical indications for dilation and irrigation.