The lacrimal system consists of lacrimal gland, caruncles, sac, and its duct. Lacrimal duct terminates in the inferior meatus and its distal opening being loosely closed by mucosal fold known as valve of Hassner. The nasolacrimald duct consists of intraosseous and meatal segment which measures 12 mm and 3 mm respectively. Tears being drained by an active process contributed by blinking. It is important to know the anatomical landmark of nasolacrimal duct when performing endoscopic sinus surgery to avoid unnnecessary dissection and potential complications.
Figure shows flourescein dye draining into inferior meatus after its instillation
into the left eye in a patient who underwent an opthalmic assessment.
This figure shows yellow flourescein dye flowing into the nasopharynx upon it exits from the inferior meatus. It indicates an intact nasolacrimal passage.
In this instance, the dye was used for the purpose of ophthalmic assessment
of corneal ulcer.
[IT- inferior turbinate, TT- torus tubarius, SP- soft palate, stars- flourescein dye]
Dacrocystogram is the imaging of choice for the assessment of blocked nasolacrimal duct in a patient who may need a definitive
endoscopic surgical management.
Watch video of flourescein dye flowing into the nasopharynx @ YouTube
Endoscopic view of right nasal cavity after topical decongestant nasal spray. (S - nasal septum, IT - inferior turbinate, MT - middle turbinate)
The lateral wall of right inferior meatus showing a widely patent natural nasolacrimal duct opening (arrow) of the same patient. (IT - inferior turbinate). Normally, the opening is covered by mucosal fold known as valve of Hassner.
These figures showed the silicone stent tubing in-situ (black arrow) after
an endoscopic dacrocystorhinostomy performed for right nasolacrimal duct obstruction. It will be taken out after the newly formed tract
epitheliazed in a few months time.
The distal end in the nasal cavity being secured in place by using a Ligaclip (yellow arrow). A small granulation noted on the lateral wall (white dotted circle). [S- nasal septum, LW- lateral wall of nasal cavity]
Watch video of e-DCR post-operative view @ YouTube
Green arrow- nasolacrimal duct opening
S- nasal septum
MT- middle turbinate
IC- inferior concha with mucosal cover
Watch video of nasolacrimal duct end post-inferior turbinectomy @ YouTube