Lacrimal system and dry eyes

Question 1

Function of lacrimal gland

Answer 1

Forms the aqueous layer of the tear film

Question 2

Pathway of lacrimal system

Answer 2

Lacrimal gland → puncta → canaliculi → Lacrimal sac → nasolacrimal
duct → inferior nasal meatus

See picture

Question 3

Parts of lacrimal gland?

Answer 3

-Orbital part: Lies in the frontal bone.
-Palpebral part: Located superolaterally in the eyelids, inferior to the levator palpebrae muscle

Question 4

Blood supply lacrimal gland

Answer 4

Lacrimal artery, a branch of the ophthalmic artery

Question 5

Nerve supply lacrimal gland

Answer 5

Sensory: Lacrimal nerve (CNV1).
● Parasympathetic secretomotor: CNVII. Pathway: preganglionic
parasympathetic fibres originate from the superior salivatory nucleus
in the pons and travel with the greater petrosal nerve (a branch of the
CNVII) to synapse at the pterygopalatine ganglion. Postganglionic fibres
then joins the lacrimal branch of CNV1 to supply the lacrimal gland

Question 6

Acquired obstruction

Answer 6

Punctal stenosis

Nasolacrimal obstruction

Question 7

Punctal stenosis causes and treatment

Answer 7

• Causes: Idiopathic or chronic blepharitis.
• Treatment: Punctoplasty.

Question 8

Nasolacrimal obstruction

Answer 8

• Causes: Idiopathic, trauma, surgery or tumours.
• Treatment: Dacryocystorhinostomy (anastomosis of lacrimal sac with
  mucosa of middle meatus).

Question 9

Congenital nasolacrimal duct obstruction

Answer 9

Can occur in newborns

90% of cases resolve within the first 12 months of life. Typically occurs at valve of Hasner

Question 10

Congenital nasolacrimal duct obstruction features and treatment

Answer 10

Features: Epiphora, Mucopurulent discharge on pressure over lacrimal sac

Treatment:
1st line - Observation and massaging of the lacrimal sac for the first 12 months of life
2nd line - Nasolacrimal duct probing
3rd line - Nasolacrimal duct stent insertion, balloon dilatation, or dacrycystorhinostomy

Question 11

What is canaliculitis?

Answer 11

This is an infection of the canaliculi most commonly due to Actinomyces israelii.
Usually presents unilaterally with epiphora, red eye and discharge on pressure
over the canaliculus.

Management: Topical antibiotics

Question 12

What is dacryoadenitis?

Answer 12

Idiopathic lacrimal gland inflammation

Question 13

Causes of dacryoadenitis

Answer 13

Tear stasis
Viral infections e.g mumps
Sarcoidosis (cause bilateral)

Question 14

Features of dacryoadenitis

Answer 14

• Painful, tender, erythematous and swollen lacrimal gland (superolateral
  upper eyelid).
• Disturbed tear production.
• S-shaped ptosis of the upper eyelid.
• Downward and inward displacement of the globe

Question 15

What is dacryocystitis?

Answer 15

Infection of the lacrimal sac due to an obstruction in the nasolacrimal duct. Most
commonly due to Staphylococcus aureus, S. epidermidis (in adults), Streptococcus
pneumoniae or Haemophilus influenzae (in children).

Question 16

Features and mx of dacrocystitis?

Answer 16

Acute
● Erythematous, tender swelling over the lacrimal sac with associated
epiphora.
● Treat with warm compresses, systemic antibiotics and
dacryocystorhinostomy after the acute phase has completely resolved to
reduce the risk of recurrence.
Chronic
● Epiphora and recurrent unilateral conjunctivitis.
● Treat with dacryocystorhinostomy

Question 17

Pleomorphic adenoma of lacrimal gland

Answer 17

Most common lacrimal gland tumour, occurring in middle-aged patients. Benign,
but can transform into malignant.
● Histopathology: Epithelial and mesenchymal components.
● Features: Progressive, painless enlargement of the upper eyelid with
inferonasal dystopia.
● Investigation: CT scan.
● Treatment: Surgical excision

Question 18

Lacrimal gland carcinoma

Answer 18

A rare, malignant tumour of the lacrimal gland.
● Histopathology: The main type is adenoid cystic carcinoma, which
exhibits a cribriform or ‘Swiss cheese’ growth pattern. Other types include
pleomorphic adenocarcinoma and mucoepidermoid carcinoma.
● Features: Rapidly growing and painful lacrimal gland mass,
inferonasal dystopia, optic disc swelling, choroidal folds and may cause
perineural invasion (spreading of a cancer around a nerve causing
neurological deficits).
● Management: Biopsy, orbital exenteration (surgical removal of the globe and
surrounding tissue), radical orbitectomy and/or radiotherapy.

Question 19

Xeropthalmia

Answer 19

Xerophthalmia is caused by severe vitamin A deficiency, which is a major cause
of childhood blindness in Africa.
FEATURES
● Nyctalopia
● Xerosis: Severe conjunctival dryness and keratinization
● Bitot’s spots: Triangular keratinized buildup on the conjunctiva
● Punctate corneal epithelial erosions
● Keratomalacia in severe cases
MANAGEMENT
Vitamin A supplementation and topical lubrication

Question 20

What is Sjorgen syndrome

Answer 20

An autoimmune condition in which the salivary and lacrimal glands become
infiltrated with lymphocytes and the acini are progressively destroyed

Question 21

Features of sjorgen syndrome

Answer 21

Triad: Xerostomia, keratoconjunctivitis sicca and parotid gland enlargement.
● Posterior blepharitis is commonly present.
● Corneal punctate epithelial erosions (stains with fluorescein).
● Strands of filaments containing mucus or debris (stains with rose bengal)

Question 22

Investigations for Sjorgen syndrome

Answer 22

Anti-Ro and anti-La antibodies.
● Reduced tear film breakup time.
● Schirmer test: Determines whether the eye produces enough tears to keep it
moist.
● Ocular staining: Showing interpalpebral staining of cornea and conjunctiva,
rather than a superior or inferior stain pattern seen in superior limbic
keratoconjunctivitis or exposure keratopathy, respectively.

Question 23

Management of Sjorgens

Answer 23

● First line: Ocular lubricants and artificial tears: includes hypromellose
(lowest viscosity), carbomer and paraffins (highest viscosity).
● Second line: Topical corticosteroids and/or oral pilocarpine (increases
lacrimal gland secretion).
● Third line: Punctal occlusion or low-water content bandage contact lenses
(e.g. silicone hydrogel)