Transcript Lachrymal system

Prof Dr Rengin YILDIRIM
.
The majority of tears are produced
by
accessory tear glands located within
the
eyelid and conjunctiva. The lacrimal
gland itself is really only responsible
for
reflexive tearing. Tears flow down
the
front of the eye and drain out small
pores,
called lacrimal punctum
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Each punctum is present at the medial end of
both the superior and inferior lid.
They are situated on slight elevations called
the lacrimal papillae and face posteriorly so it
is necessary to evert the medial lids to
inspect them.
Malposition or stenosis (narrowing) of the
puncta may cause epiphora.
This is about 2mm long and joins the
horizontal canaliculus at a right angle called
the ampulla.
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This is about 8mm long and usually joins its
fellow to form the common canaliculus which
immediately enters the (naso)lacrimal sac
through the Valve of Rosenmuller (flap of
mucosa to prevent reflux).
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This is about lOmm long and funnels into the
nasolacrimal duct.
This is about l2mm long and opens into the
inferior nasal meatus, lateral to the inferior
turbinate (concha). The Valve of Hasner
closes the opening.
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About seven other valves have been
described within the nasolacrimal duct
besides those of Rosenmuller and Horner (see
Last) but they have no valvular function and
are usually ignored
Capillarity ensures that 70%
of the tears enter the
inferior canaliculus and 30%
through the superior .
On blinking, the attachment
of the preseptal orbicularis
muscle helps create positive
and negative pressure in the
lacrimal sac which sucks the
tears into it .
This is called the tear
pump. Gravity then helps
keep the sac empty.
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hypersecretion occurs when a foreign body
irritates the cornea.
Paradoxically, it may also be due to an
underlying dry eye problem which, in turn,
causes a foreign body reaction and tearing.
Likewise, it may be due to a lacrimal pump
failure as in ectropion when tears are no
longer able to enter the punctum. It may also
be caused by punctum plugs or punctum
cauterisation for the treatment of dry eye.
Inspect the lids to see if they and/or the
puncta are poorly positioned. Palpate the
lacrimal sac to determine if it is enlarged
due to dacryocystitis or a mucocele.
Compression may cause a reflux of
mucopurulent matter. Pain suggests
dacryocystitis.
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Inspect the puncta for poor position,
narrowing or blockage - pouting suggests
canaliculitis.
A high marginal tear strip may indicate
epiphora. If fluorescein is instilled in the
conjunctival sac, it should disappear within
two minutes - retention suggests there is a
problem with lacrimal drainage.
If the cannula touches the
medial wall of the lacrimal
sac and lacrimal bone, a
definite end point is
reached. This is a 'hard
stop‘ and indicates that
there is no complete
obstruction in the
canalicular system
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If a spongy end point is
felt, this is termed a 'soft
stop’ and indicates that the
cannula has been prevented
from entering the lacrimal
sac. Therefore, there is a
blockage in the canalicular
system and there will be no
distension of the lacrimal
sac when the plunger is
pressed
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If saline refluxes from the inferior canaliculus,
the blockage is there.
If saline refluxes from the superior canaliculus,
the blockage is in the common canaliculus.
If saline passes into the nose, the problem is
hypersecretion of tears or failure of the lacrimal
pump or partial obstruction of the nasolacrimal
system.
If saline does not reach the nose, there is a total
obstruction of the nasolacrimal duct and saline
may appear from the superior punctum - the
saline may be purulent if infection is present and the lacrimal sac may be distended
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Sometimes, the lacrimal drainage system may
appear patent when syringing proceeds
uneventfully.
However, there may be a functional
obstruction. This means that under the lowpressure circumstances of normal tear
drainage, all or part of the lacrimal pathway
may collapse.
Jones dye tests may be used to distinguish
between patent systems and functionally
blocked ones
Instil one drop of fluorescein
into the conjunctival sac
Put a cotton bud soaked in
anaesthetic in the inferior
meatus.
If fluorescein is detected after
five minutes, the system is
patent (positive Primary Jones
Test).
If no fluorescein is discovered,
this is a negative Primary Jones
Test and the functional
obstruction could be anywhere
from the punctum to the Valve
of Hasner.
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Next, wash the excess fluorescein
from the conjunctival sac and
syringe. If fluorescein is detected,
then this shows it had entered the
sac and constitutes a positive
Secondary Jones Test and
suggests a functional obstruction
of the nasolacrimal duct.
If no dye is found on the cotton
bud after syringing, this is termed
a negative Secondary Jones Test,
because fluorescein had not
entered the sac and, thus, there is
stenosis of the puncta or
canalicular system
If no saline appears in the nose,
there is a complete obstruction
somewhere in the lacrimal
drainage system.
Tear meniscus
• Dye disappearance test
• Irrigation (GA)
•
Membranous block of the valve of Hasner
at the nasal end of the nasolacrimal duct.
• Present in 50% of newborns
• Clinically evident in 2-6% at 3-4 weeks
after birth.
• 1/3 bilateral.
• 90% resolves in the first year of life.
•
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Massage
Probing +/- Silicone Intubation.
Hyper secretion (lacrimation)
• Impaired drainage (epiphora)
•
Irrigation
• Dye disappearance test
• Johns tests
• Scintigraphy
• Contrast dacryocystography
• CT scan
•
Dacryocysorhinostomy (DCR)
Inflammation of the lacrimal sac secondary
to NLD Obstruction.
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Warm compressors
Oral/ IV broad spectrum antibiotics
Drainage of the abscess
DCR