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1. Acquired Nasolacrimal Duct
Obstruction:
Etiology & Managment
Neda Ahmadi
PGY-4
11/18/10
Georgetown University Hospital

2. Case Presentation

3. Imaging

4. Outline

5. Anatomy
• Puntal opening - ~0.3mm in diameter
• Canaliculus - Extends 2mm vertically
• Turns 90 degrees toward the medial canthus &
travels through the orbicularis muscle (8mm)
• Inferior & superior canaliculi form a common
canaliculus - 90% to 94% of individuals
• Common canaliculus and lacrimal sac -
Between ant. & post limbs medial canthal ligament
(MCL)
• Valve of Rosenmuller
• Lacrimal sac – 12-15 mm
Extends 3-5mm superior to MCL
Chastain JB, Sindwani R. Anatomy of the orbit, lacrimal apparatus, and lateral nasal wall. Otolaryngol Clin North Am. 2006 Oct;39(5):855-64, v-
vi.

6. Anatomy
•Lacrimal sac lies within the lacrimal fossa
•Avg. width of lacrimal fossa – 8mm
•Anterior lacrimal crest - Formed by frontal process
of maxilla
•Posterior lacrimal crest - Formed by lacrimal bone
Chastain JB, Sindwani R. Anatomy of the orbit, lacrimal apparatus, and lateral nasal wall. Otolaryngol Clin North Am.
2006 Oct;39(5):855-64, v-vi.

7. Intranasal Anatomy
• Frontal process of maxilla covers anterior half of sac
• Thin lacrimal bone covers posterior half.
• Almost always sac lies anterior to middle turbinate
• 0% and 20% of sac - Above the attachment of MT
• Sac extends on average 8.8mm superior to insertion of MT
Wormald PJ, et al. Intranasal anatomy of the nasolacrimal sac in endoscopic dacryocystorhinostomy. Otolaryngol
Head Neck Surg. 2000 Sep;123(3):307-10.

8. • Retrospective study
• 38 subject w/ recurrent epiphora - CT dacryocystogram (DCG)
• Height of sac measured
Common Canaliculus Middle turbinate insertion

9. Conclusions
•No difference between measurements taken in relation to the long
axis of the sac and those parallel to supraorbital ridge (P>0.05)
•A major portion of the sac was located above the MT
•The common canaliculus provides a valuable landmark for
endoscopic surgeon bc a significant portion of sac lies above its
insertion.
Wormald PJ, et al. Intranasal anatomy of the nasolacrimal sac in endoscopic dacryocystorhinostomy. Otolaryngol
Head Neck Surg. 2000 Sep;123(3):307-10.

10. Intranasal anatomy
• NLD - ~4mm anterior to maxillary sinus ostium (MSO)
• NLD orifice - Roof of inferior meatus
• ~25mm from anterior nasal spine
• ~13.7 +/- 3.15mm from nasal floor
• ~14.3 +/- 2.05mm from anterior attachment of inferior turbinate
• NLD courses superiorly and anteriorly from the orifice toward the anterior
attachment of MT
• Average NLD length - 22mm (18-24mm)
Intraosseous – 12mm
• R & L canals run parallel
Slope posteriorly 15-25
o
Tatlisumak E et al. Surgical anatomy of the nasolacrimal duct on the lateral nasal wall as revealed by serial dissections. Anat Sci Int. 2010
Mar;85(1):8-12.
Janssen AG, Diameter of the bony lacrimal canal: normal values and values related to nasolacrimal duct obstruction: assessment with CT.
AJNR Am J Neuroradiol. 2001 May;22(5):845-50.

11. Maxillary Line
• Curvilinear eminence along the lateral nasal wall
• Chastain et al. 2005
– Objective: Describe the anatomic relations of maxillary line
– Intranasally - Attachment of the uncinate process to the maxilla
– Extranasally - Suture line between the lacrimal bone and the frontal
process of the maxilla within the lacrimal fossa
– M point ~10.8 mm anterior to maxillary ostium
– Axial line drawn through the M point –
Level of the superior margin of the MSO posteriorly
& just inferior to the lacrimal sac-duct junction
anteriorly
– M point within 3mm of lacrimal apparatus in all but 1 specimen
– ~1/2 lacrimal sac - Anterior to this line
Chastain JB et al. The maxillary line: anatomic characterization and clinical utility of an important surgical landmark.
Laryngoscope. 2005 Jun;115(6):990-2.

12. • Retrospective study; 314 patients (64% M: 36% F) w/o epiphora or
pathologic conditions affecting NLD
• Axial maxillofacial CT (3-4mm)
• Results
– Mean AP diameter 5.6 mm (0.4-10.9mm)
– Mean transverse 5.0mm (2.2-8.7mm) diameter
– AP diameter greater in M (5.8mm) vs F (5.3mm) (P<0.001)
– Transverse diameter greater in M (5.1mm) vs F (4.8mm) (P<0.005)
– Cross sectional area of bony NLD greater in M (23.6mm
2
) vs. F (20.6mm
2
)
(P<0.001)
Shigeta K et al. Sex and age differences in the bony nasolacrimal canal: an anatomical study. Arch Ophthalmol. 2007
Dec;125(12):1677-81.

13. Age affected
•Male
–Transverse diameter (P=0.002),
–Cross sectional area (P=0.002)
–Trend for AP diameter to increase with age
(P=0.04)
•Female
–AP diameter (P<0.001)
–Cross sectional area (P,0.001)
–Trend for transverse diameter to increase with
–age (P=0.02)
Overall
•Female
–AP diameter ~0.6mm smaller
–Transverse diameter ~0.3mm smaller
–Cross sectional area ~13% smaller in F pts

14. Etiology
•3% of all ophthalmology visits
•Congenital
–Prevalence ~20%
–Most common cause – Persistent membrane at valve of Hasner
–Normally resolves spontaneously at 6-14 months of age
•Acquired
–Incidence - 20.24 per 100,000
–Presenting symptoms
•Epiphora
•Dacryocystitis
Lee-Wing MW, Clinicopathologic analysis of 166 patients with primary acquired nasolacrimal duct obstruction.
Ophthalmology. 2001 Nov;108(11):2038-40.

15. Examination
• Lacrimal pump function
– Lower punctum – Medial translation and inward rotation normally w/ blinking.
– Not observed – Consider lacrimal pump failure
• Shirmer testing
– Measures basal & stimulated
– Differentiates primary hypersecretion from reflex hypersecretion
– W/o anesthesia (Stimulated)
–Normal – 10-30mm at 5 min
–<10mm at 5min indicates dry eye which may be associated with reflex
hypersecretion and epiphora
– W/ anesthesia (Basal)
• Normal - >10mm at 5 min
• Primary hypersecretion if whole strip wet

16. Examination
•Jones I