A short compilation on Congenital Nasolacrimal Duct Obstruction

1. Congenital Nasolacrimal Duct
Obstruction
Raju Kaiti
Consultant Optometrist
Dhulikhel Hospital, KU

2. Lacrimal Apparatus
• Secretory apparatus
– Main lacrimal gland
– Accessory lacrimal glands
–
• Non secretory apparatus
– Lacrimal drainage system
Lacrimal punctum
Lacrimal canaliculus
Lacrimal sac
Nasolacrimal duct

3. Lacrimal Gland
• Location – anterolateral area of orbital
roof
• Shape- almond
• Parts:
– Upper: orbital part
– Lower: palpebral part
• Ducts of lacrimal gland opens in the
lateral part of superior fornix (10 -12
ducts) and of inferior fornix (1-2 ducts)

4. Accessory Lacrimal Glands
• Glands of Krause – lies beneath the palpebral conjuntiva
between fornix and the edge of tarsus
– upper fornix –( 42)
– lower fornix – (6-8)
• Glands of Wolfring – upper border of superior tarsal plate
borders – (2-5)

5. • All lacrimal glands are serous acini, similar in structure to
salivary glands
• Blood supply:
– Main lacrimal gland is supplied by lacrimal artery which is
a branch of ophthalmic artery.
• Nerve supply:
(1) Sensory supply comes from lacrimal nerve, a branch of the
ophthalmic division of the fifth nerve
(2) Sympathetic supply comes from the carotid plexus of the
cervical sympathetic chain
(3) Secretomotor fibres are derived from the superior salivary
nucleus.

6. Lacrimal Drainage System
• Punta
• Ampulla
• Canaliculi
• Common canaliculus
• Lacrimal sac
• Naso- lacrimal duct
• Inferior nasal meatus

7. Puncta (Puctum)
• 6 mm temporal to the inner canthus
• Each punctum situated upon lacrimal papilla (prominent in
old age)
• Puncta dip into the lacus lacrimalis (collection of tear fluid in
the inner canthus)

8. Lacrimal Canaliculi
• Upper and lower
• Parts:
– Vertical -2mm
– Horizontal – 8 mm
• Join to form common canaliculus
• Open in the lacrimal sac, fold of mucosa forms the valve of
Rosenmuller which prevents reflux of tears.

9. Lacrimal sac
• lies in the lacrimal fossa located in the anterior part of medial orbital wall
• The lacrimal fossa is formed by lacrimal bone and frontal process of
maxilla and separate the lacrimal sac from the middle meatus of the nasal
cavity
• When distended: 15 mm in length and 5-6 mm in breadth
• Parts:
– fundus (portion above the opening of canaliculi),
– body (middle part)
– neck (lower small part which is narrow and continuous with the
nasolacrimal duct)
LININGS-by nonkeratinized stratified squamous epithelium and are
surrounded by elastic tissue, which permits dilation to 2 or 3 times the
normal diameter.

10. Naso – Lacrimal Duct
• Neck of lacrimal sac to inferior meatus in the nose
• Lies in a bony canal – mainly maxilla and inferior turbinate
• 18 mm in length
Intraosseous part 12.5mm
Intrameatal 5.5mm
• Diameter-3mm
• Direction- downwards, backward & laterally
• Externally its location is represented by a line joining inner canthus to the
ala of nose
• upper end -narrowest part
• valve of Hasner, present at the lower end of the duct and prevents reflux
from the nose

11. Physiology
• Tears secreted by the main and accessory lacrimal glands pass
laterally across the ocular surface
• Tears evaporates depending on
– size of the palpebral aperture
– blink rate
– ambient temperature
– humidity

12. • Tears flow along the upper and lower marginal strips
• enter the upper(30%) and lower(70%) canaliculi by
capillarity and also possibly by suction

13. • With each blink, the pretarsal orbicularis oculi compresses the
ampullae, shortens the horizontal canaliculi and moves the puncta
medially
• The lacrimal part of the orbicularis oculi, which is attached to the
fascia of the lacrimal sac contracts and expands the sac creates
a negative pressure sucks the tears from the canaliculi into the sac.

14. • When the eyes open the muscles relax. the sac collapses and
a positive pressure is created which forces the tears down the
nasolacrimal duct into the nose
• Gravity also plays a role.
• The puncta move laterally.
• The canaliculi lengthen and fill with tears.

15. Obstructions at lacrimal drainage system
• common canalicular block: Clear fluid opposite
punctum
• same canaliculus block: Clear fluid from same punctum
• nasolacrimal duct block: Mucoid fluid from opposite
punctum

16. Congenital nasolacrimal duct
obstruction (CNLDO)
• More typical nonemergency obstruction of NLD in 5% of full
term newborns
• Delayed canalization of the NLD after birth
• In fetus, the NLD is a solid cord of cells, which gets canalized
at birth
• In 30% of new borns canalization is delayed

17. Signs
20% of children manifest evidence of NLD obstruction in 1st
year of life
• Epiphora and matting of lashes may be constant or
intermittent when the child has a cold or URTI
• Gentle pressure over the lacrimal sac causes reflux of purulent
material from the puncta

18. • congenital NLD blockage causes epiphora predisposing to
congenital dacryocystitis.

19. Treatment
1. Massage of the lacrimal sac
• To perform this manoeuvre, the index finger is placed
over the common canaliculus to block reflux through
the puncta and then massaged firmly downwards.
• Ten strokes are applied four times a day.
• Massage should be accompanied by lid hygiene; topical
antibiotics should be reserved for superadded bacterial
conjunctivitis.

20. .
2. Probing of the lacrimal system

21. • delayed until the age of 12–18 months because
spontaneous canalization is likely.
• Probing performed within the first 1–2 years of life has
a very high success rate, but thereafter the efficacy
decreases
• The procedure should be carried out under a general
anaesthetic.
• The rationale is to manually overcome the obstructive
membrane at the Hasner valve.

22. • After probing, the lacrimal system is irrigated
with saline labelled with fluorescein.
• If fluorescein can be recovered by aspiration from
the pharynx, successful probing is confirmed.
• Postoperative steroid-antibiotic drops are used
q.i.d. for up to 3 weeks.
• If, after 6 weeks, there is no improvement,
repeat probing can be arranged.

23. Results
• Usually excellent and 90% of children are cured by the first probing
and more than half of the remainder by the second.
• Failure is usually the result of abnormal anatomy, which can usually
be recognized by difficulty in passing the probe and subsequent
non-patency of the drainage system on irrigation.
• If symptoms persist despite one to two technically satisfactory
probings, temporary intubation with fine silastic tubes with or
without balloon dilatation of the nasolacrimal duct may affect a
cure.
• Patients who fail to respond to such measures can be treated later
with DCR, provided the obstruction is distal to the lacrimal sac.

24. • Conventional Dacryocystorhinostomy
• The blood vessels in the middle
nasal mucosa are constricted with
ribbon gauze or cotton buds lightly
wetted with 1 : 1000 adrenaline.
• A straight vertical incision is made
10 mm medial to the inner canthus,
avoiding the angular vein (Fig. 2.18A).
Lacrimal surgery

25. • The anterior lacrimal crest is
exposed by blunt dissection
and the superficial portion of
the medial palpebral ligament
divided.
• The periosteum is divided
from the spine on the
anterior lacrimal crest to the
fundus of the sac and
reflected forwards. The sac is
reflected laterally from the
lacrimal fossa (Fig. 2.18B).

26. • The anterior lacrimal
crest and the bone from
the lacrimal fossa are
removed (Fig. 2.18C).
• A probe is introduced
into the lacrimal sac
through the lower
canaliculus and the sac
is incised in an ‘H-
shaped’ manner to
create two flaps.

27. • Membranous obstruction
at the common canalicular
opening or distal canalicular
obstruction can be opened
by excision or trephine of
obstructing tissue
(canaliculo-DCR).
• A vertical incision is made
in the nasal mucosa to
create anterior and
posterior flaps (Fig. 2.18D).

28. • The posterior flaps
are sutured (Fig. 2.18E).
• Silicone intubation
may be performed.

29. • The anterior flaps are
sutured (Fig. 2.18F).
• The medial canthal
tendon is resutured to
the periosteum and the
skin incision closed with
interrupted sutures

30. Results
• excellent with a success rate of over 90%.

31. Causes of failure
• inadequate size and position of the ostium,
unrecognized common canalicular obstruction, scarring
and
• The ‘sump syndrome’, in which the surgical opening in
the lacrimal bone is too small and too high.
There is thus a dilated lacrimal sac lateral to and below
the level of the inferior margin of the ostium, in which
secretions collect, unable to gain access to the ostium
and thence the nasal cavity.

32. Complications
• Cutaneous scarring
• Injury to medial canthal structures
• Haemorrhage
• Cellulitis
• Cerebrospinal fluid rhinorrhoea if the
subarachnoid space is inadvertently entered.