Lacrimal Drainage System

Question 1

What structures make up the lacrimal drainage system

Answer 1

1) Puncta
2) Cannaliculi
3) Lacrimal sac
4) Nasolacrimal duct

Question 2

What is the punctal anatomy?

Answer 2

located at the posterior edge of the lid margin. Normally they face slightly posteriorly and can be inspected by everting the medial aspect of the lids. Treatment of watering caused by punctal stenosis or malposition is relatively
straightforward

Question 3

What is the cannaliculi anatomy?

Answer 3

pass vertically from the lid margin for about 2 mm (ampullae). They then turn medially and run horizon-
tally for about 8 mm to reach the lacrimal sac. The superior and
inferior canaliculi usually (>90%) unite to form the common
canaliculus, which opens into the lateral wall of the lacrimal
sac.

Rosenmüller valve) overhangs
the junction of the common canaliculus and the lacrimal
sac (the internal punctum) and prevents reflux of tears into
the canaliculi.

Question 4

What is the lacrimal sac anatomy?

Answer 4

10–12 mm long and lies in the lacrimal fossa between the anterior and posterior lacrimal crests. The
lacrimal bone and the frontal process of the maxilla separate
the lacrimal sac from the middle meatus of the nasal cavity.

In a dacryocystorhinostomy (DCR) an anastomosis is created
between the sac and the nasal mucosa to bypass an obstruction
in the nasolacrimal duct.

Question 5

What is the nasolacrimal duct anatomy?

Answer 5

12–18 mm long and is the inferior
continuation of the lacrimal sac. It descends and angles slightly
laterally and posteriorly to open into the inferior nasal meatus,
lateral to and below the inferior turbinate. The opening of the
duct is partially covered by a mucosal fold (valve of Hasner).

Question 6

How do tears flow and drain?

Answer 6

Tears flow along the upper and lower marginal strips pooling in the lacus lacrimalis medial to the lower
puncta, then entering the upper and lower canaliculi by a combination of capillarity and suction.

With each blink, the pretarsal orbicularis oculi muscle com-
presses the ampullae, shortens and compresses the horizontal
canaliculi and closes and moves the puncta medially, resisting
reflux. Simultaneously, contraction of the lacrimal part of the orbicularis oculi creates a positive pressure that forces tears down the nasolacrimal duct and into the nose, mediated by
helically arranged connective tissue fibres around the lacrimal sac

Question 7

Causes of a watery eye?

Answer 7

Hypersecretion
Defective drainage

Question 8

Differentiating drainage failure from hypersecretion based on history taking?

Answer 8

rainage failure tends to be
exacerbated by a cold and windy environment and to be least
evident in a warm dry room. A complaint of the tears overflowing
onto the cheek is likely to indicate drainage failure rather than
hypersecretion.

Question 9

What is conjunctivochalasis and what is it caused by?

Answer 9

Punctal obstruction, usually partial, by a fold of redundant conjunctiva is common but underdiagnosed

It is thought to be predominantly an involutional process involving the loss of conjunctival adhesion to underlying Tenon capsule and episclera and may be analogous to the conjunctival abnormalities leading to superior limbic keratoconjunctivitis

Question 10

What is Centurion syndrome?

Answer 10

characterized by anterior malposition of the medial part of the lid, with displacement of puncta out of the lacus lacrimalis due to a prominent nasal bridge.

Question 11

What can a watery eye in a child be?

Answer 11

Congenital glaucoma
Punctal atresia
Chronic conjunctivitis (e.g. chlamydial),
Keratitis and
Uveitis.

Question 12

What is a mucocele and how can it be diagnosed?

Answer 12

Punctal reflux of mucopurulent material on compression is indicative of a mucocoele

Question 13

What is the normal marginal tear strip (mm)

Answer 13

0.2-0.4mm

Question 14

What is a hard stop when assessing lacrimal function?

Answer 14

occurs if the cannula enters the lacrimal sac, coming to a stop at the medial wall of the sac, through which can be felt the rigid lacrimal bone. This excludes complete obstruction of the canalicular system.

Failure of saline to reach the throat is
indicative of total obstruction of the nasolacrimal duct. In this situation, the lacrimal sac will distend slightly during irrigation and there will be reflux, usually through both the upper and lower puncta.

Question 15

What is a soft stop when assessing lacrimal function?

Answer 15

if the cannula stops at or proximal
to the junction of the common canaliculus and the lacrimal
sac. The sac is thus not entered – a spongy feeling is experienced as the cannula presses the soft tissue of the common canaliculus and the lateral wall against the medial wall of the
sac and the lacrimal bone behind it.

In the case of lower canalicular obstruction, a soft stop will be
associated with reflux of saline through the lower punctum.
Reflux through the upper punctum indicates patency of both
upper and lower canaliculi, but obstruction of the common
canaliculus.

Question 16

When is dye testing indicated to assess lacrimal function?

Answer 16

only in patients with suspected partial obstruction of the drainage system. Epiphora is present, but there is no punctal abnormality and the patient tastes saline in his or her
throat on irrigation.

Question 17

What is the Jones Primary Test?

Answer 17

differentiates partial obstruc-
tion of the lacrimal passages and lacrimal pump failure from
primary hypersecretion of tears. A drop of 2% fluorescein is instilled into the conjunctival sac of one eye only. After about 5 minutes, a cotton-tipped bud moistened in local anaesthetic is inserted under the inferior turbinate at the nasolacrimal duct opening.

Question 18

What does a positive primary Jones test indicate?

Answer 18

fluorescein recovered from the nose indicates patency of the drainage system. Watering is due to primary
hypersecretion and no further tests are necessary.

Question 19

What does a negative Primary Jones Test indicate?

Answer 19

No dye recovered from the nose indicates a partial obstruction (site unknown) or failure of the lacrimal pump mechanism. In this situation the secondary dye test is performed immediately. There is a high false-
negative rate – that is, dye is commonly not recovered even in the presence of a functionally patent drainage system. Modifications involving direct observation of the
oropharynx using cobalt blue light for up to an hour may
reduce the false-negative rate almost to zero.

Question 20

What is the secondary Jones Test?

Answer 20

Identifies lacrimal pump failure or the probable site of partial obstruction, on the basis of whether the topical fluorescein instilled for the primary test entered the lacrimal sac. Topical anaesthetic is instilled and any residual fluorescein washed out from the conjunctival fornix. The drainage system is then irrigated with a cotton bud under the inferior turbinate.

Question 21

What does a positive Secondary Jones test mean?

Answer 21

fluorescein-stained saline recovered from the nose indicates that fluorescein entered the lacrimal sac, thus confirming functional patency of the upper lacrimal passages. Partial obstruction of the nasolacrimal duct
distal to the sac is inferred

Question 22

What does a negative Secondary Jones test mean?

Answer 22

unstained saline recovered from the nose indicates that fluorescein did not enter the lacrimal sac. This
implies upper lacrimal (punctal or canalicular) dysfunction, which may be due to partial physical occlusion and/ or pump failure.

Question 23

What is contrast dacryocystography?

Answer 23

involves the injection of
radio-opaque contrast medium (ethiodized oil) into the canaliculi
followed by the capture of magnified images.

Question 24

What are the indications for contrast dacryocystography?

Answer 24

confirmation of the precise site of lacrimal drainage obstruction to
guide surgery and the diagnosis of diverticuli, fistulae and filling
defects (e.g. stones, tumours).

Question 25

When should contrast dacryocystography not be performed?

Answer 25

presence of acute infection.

A DCG is unnecessary if the site of
obstruction is obvious (e.g. regurgitating mucocoele). A normal
dacryocystogram in the presence of subjective and objective epiphora suggests failure of the lacrimal pump, though this is more readily demonstrated by simple irrigation.

Question 26

What is nuclear lacrimal scintigraphy?

Answer 26

assesses tear drainage under more
physiological conditions than DCG, by labelling the tears with a
radioactive substance and tracking their progress.

Although it does not provide the same detailed anatomical visualization as DCG, it may be used to identify the location of a partial or functional block (e.g. indicating the absence of significant tear entry to the canaliculi, localizing the site of physiological obstruction to the
eyelids), to confirm functional obstruction, or sometimes to
confirm the presence of normal drainage such that surgery is not
indicated.

Question 27

How is conjunctivochalasis managed?

Answer 27

*Observation or lubricants alone may be appropriate in mild
cases.

*Topical steroids or other anti-inflammatories.

• Surgical options include securing the bulbar conjunctiva to
  the sclera with three absorbable sutures (e.g. 6-0 polyglactin)
  placed 6–8 mm from the limbus, or excision of a crescent-
  shaped area of excess bulbar conjunctiva, with an anterior
  limit of around 6 mm from the limbus. Suturing the edges
  of the excised patch together, or replacement with amniotic
  membrane have been described.

Question 28

What is primary punctal stenosis and what causes it?

Answer 28

Primary stenosis occurs in the absence of punctal eversion. The most common causes are chronic blepharitis and idiopathic stenosis. Other causes include herpes simplex and herpes zoster lid infection, local radiotherapy, cicatrizing conjunctivitis, chronic topical glaucoma treatment, systemic cytotoxic drugs such as 5-fluorouracil and rare systemic conditions such as porphyria cutanea tarda.

Question 29

How can primary punctal stenosis be managed?

Answer 29

• Dilatation of the punctum alone can be tried but rarely gives
  sustained benefit.
• Punctoplasty is usually required. A number of techniques have
  been described, including one-, two-or three-snip enlargement with removal of the posterior ampulla wall and procedures using a mechanical punch, laser or microsurgery; a
  temporary stent can be used.

Question 30

What is secondary punctal stenosis and what causes it?

Answer 30

Secondary stenosis occurs after punctal eversion leads to chronic
failure of tear entry and punctoplasty is usually performed in conjunction with correction of the eversion.

Question 31

How can secondary punctal stenosis be managed?

Answer 31

• Retropunctal (Ziegler) cautery can be used for pure punctal
  eversion. Burns are applied to the palpebral conjunctiva at
  approximately 5 mm below the punctum. Subsequent tissue
  shrinkage should invert the punctum.
• Medial conjunctivoplasty can be used in medial ectropion of
  a larger area of lid if there is no substantial horizontal laxity.
  A diamond-shaped piece of tarsoconjunctiva is excised, followed by approximation of the superior and inferior wound margins with sutures
• Lower lid tightening, usually with a tarsal strip, is used to correct lower lid laxity and may be combined with medial conjunctivoplasty where there is a significant medial ectropion
  component.

Question 32

What are the causes of canalicular obstruction?

Answer 32

Causes include congenital, trauma, herpes simplex infection, drugs
and irradiation. Chronic dacryocystitis can cause a membrane to form in the common canaliculus.

Question 33

How can partial obstruction of the canaliculi be treated?

Answer 33

by simple intubation of one or both canaliculi with silicone stents. These are left in situ for 6 weeks to 6 months

Question 34

How can total obstruction of the canaliculi be treated?

Answer 34

Canalicular trephination- using an intravenous catheter with a retracted introducer needle used as a stent and then advanced to overcome the obstruction

Where obstruction is severe or it is not possible to anastomose functioning canaliculi to the lacrimal sac, conventional surgery consists of conjunctivodacryocystorhinostomy and the insertion of a toughened glass (Lester Jones) tube

Question 35

What are the causes of NLDO?

Answer 35

○ Idiopathic stenosis – by far the most common.
○ Naso-orbital trauma, including nasal and sinus surgery.
○ Granulomatous disease such as granulomatosis with polyangiitis (Wegener disease) and sarcoidosis.
○ Infiltration by nasopharyngeal tumours.

Question 36

How is NLDO treated?

Answer 36

Conventional (external approach) dacryocystorhinostomy (DCR) is indicated for obstruction distal to the medial opening of the common canaliculus and consists of anastomosis of the lacrimal sac to the mucosa of the middle nasal meatus.

Question 37

What is the technique of external DCR?

Answer 37

The procedure is usually performed under hypotensive general anaesthesia. A vertical skin incision
is made 10 mm medial to the inner canthus, the medial canthal tendon and lacrimal sac exposed and reflected and after removal of the intervening bone the sac is incised
and attached to an opening created in the nasal mucosa. The success rate is over 90%.

Question 38

What are the causes of failure of external DCR?

Answer 38

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

Question 39

What is the technique of endoscopic DCR?

Answer 39

A light pipe can be passed through the canalicular system into the
lacrimal sac to guide an endoscopic approach from within the nose, or a microendoscopic transcanalicular procedure can be performed using a drill or laser to establish communication with the nasal cavity.

Question 40

What is Dacrylolithiasis and how is it treated?

Answer 40

Dacryoliths (lacrimal stones) may occur in any part of the lacrimal system. They are more common in males.
It has been proposed that tear stagnation secondary to inflammatory obstruction may precipitate stone formation, which tends to be associated with squamous metaplasia of
the lacrimal sac epithelium

Treatment–> DCR

Question 41

What % of neonates does epiphora affect and in what % does spontaneous resolution occur?

Answer 41

Affects 20%

Spontaneous resolution within year 1 85%

Question 42

Signs of congenital NLDO?

Answer 42

Epiphora and matting of eyelashes may be constant or intermittent and may be particularly noticeable
when the child has an upper respiratory tract infection.
Superimposed bacterial conjunctivitis may be treated with
a broad-spectrum topical antibiotic.
○ Gentle pressure over the lacrimal sac may cause mucopurulent reflux.

Question 43

Treatment options for congenital NLDO?

Answer 43

Massage of the lacrimal sac has been suggested as a means of rupturing a membranous obstruction by hydrostatic pressure.

Probing. Passage of a fine wire via the canalicular system and nasolacrimal duct to disrupt the obstructive membrane at the valve of Hasner is usually regarded as the
definitive treatment and may be preceded and followed
by irrigation to confirm the site of obstruction and subsequent patency respectively. Probing can be repeated if a first procedure is unsuccessful

Options after probing failure include intubation with silastic tubing with or without balloon dilatation of
the nasolacrimal duct, endoscopic procedures and DCR.

Question 44

What is a congenital dacryocoele?

Answer 44

(amniontocoele) is a collection of amniotic fluid or mucus in the lacrimal sac caused by an imperforate Hasner valve. Presentation is perinatal with a bluish cystic swelling at or below the medial canthus

Question 45

Difference between dacryocoele and encephalocoele?

Answer 45

Dacryocoele-> collection of amni otic fluid or mucus in the lacrimal sac caused by an imperforate Hasner valve.

Encephalocoele ->a pulsatile swelling above the medial canthal tendon. Resolution is common with only conservative treatment, but if this fails, probing is usually adequate.

Question 46

What bug causes chronic canaliculitis?

Answer 46

Actinomyces israelii, anaerobic Gram-positive bacteria

Question 47

What is chronic canaliculitis?

Answer 47

Presentation is with unilateral epiphora associated
with chronic mucopurulent conjunctivitis refractory to conven-
tional treatment. There is pericanalicular redness and oedema and mucopurulent discharge on pressure over the canaliculus. A ‘pouting’ punctum is seen.

Question 48

Which bug causes acute canaliculitis?

Answer 48

HSV

Question 49

What is dacryocystitis and which bug causes it?

Answer 49

Infection of the lacrimal sac is usually secondary to obstruction
of the nasolacrimal duct. It may be acute or chronic and is most
commonly staphylococcal or streptococcal.

Question 50

When should chronic canaliculitis be suspected?

Answer 50

Chronic canaliculitis should be suspected in a patient
with unilateral mucopurulent conjunctivitis that is refractory to
conventional treatment.

Question 51

What are the presenting features of Dacryocystitis?

Answer 51

the subacute onset of pain in the medial canthal area, associated with epiphora. A very tender, tense red
swelling develops at the medial canthus commonly progressing to abscess formation. There may be associated pre-septal cellulitis

Question 52

How is acute dacryocystitis treated?

Answer 52

○ Initial treatment involves the application of warm compresses and oral antibiotics such as flucloxacillin
or co-amoxiclav. Irrigation and probing should not be performed.
○ Incision and drainage may be considered if pus points and an abscess is about to drain spontaneously. However, this carries the risk of a persistent sac–skin fistula
○Dacryocystorhinostomy is commonly required after the
acute infection has been controlled and may reduce the risk of recurrent infection and can result in closure of a fistula

Question 53

What are the features of chronic dacryocystitis?

Answer 53

Chronic epiphora, which may be associated with a chronic or recurrent unilateral conjunctivitis. A mucocoele is usually evident as a painless swelling at the inner canthus but if an obvious swelling is absent pressure over the sac
commonly still results in mucopurulent canalicular reflux.
Treatment is with DCR