Tears/Lacrimal

Question 1

Describe each of the 3 layers of te lacrimal system:

Answer 1

1. Lipid-secreted by the tarsal gland and forms a lipid layer over the edge of the eyelid and prevents tears from spilling over
2. Middle aqueous layer- makes up 90% of the thickness of the tear film and is secreted by the lacrimal gland
3. Mucin layer-has hydrophillic surface where the aqueous layer can spread and is secreted by conjunctival goblet cells

Question 2

What will happen if the stability of the tear film is compromised?

Answer 2

Tear film turbulence and resultant mixing of the layers

Question 3

What is another name for aqeuous layer deficiency?

Answer 3

keratoconjunctivitis siica

Question 4

What are the causes of keratoconjunctivitis siica?

Answer 4

1. idiopathic-postmenopausal women
2. Injury to the lacrimal gland- infections, surgery, autoimmune ,rheumatoid arthritis
3. chemical burns, Stevens Johnson Syndrome

Question 5

What are the symptoms of keratoconjunctivitis siica?

Answer 5

Burning and scratching eyes

Question 6

What is xeropthalmia?

Answer 6

Vitamin A deficiency

Question 7

What are the severe manifestations of the of damage to the cornea?

Answer 7

1. vascularisation
2. opacification
3. keratinisation

Question 8

What damage can blepharitis do to the lipid layer?

Answer 8

An abnormality or a decrease in the tarsal gland

Question 9

What causes damage to the mucin layer?

Answer 9

Any damage or destruction to the conjunctival goblet cells-chemical burns, Stevens Johnson syndrome, xerophthalmia(vitamin A deficiency)

Question 10

What do patients with mucin and lipid layer deficiciency present with?

Answer 10

Burning, scratcy eyes with paradoxical tearing

Question 11

What is trachoma?

Answer 11

Trachoma is an infectious disease caused by bacterium Chlamydia trachomatis. The infection causes a roughening of the inner surface of the eyelids. This roughening can lead to pain in the eyes, breakdown of the outer surface or cornea of the eyes, and eventual blindness.

Question 12

Define lagopthalmos:

Answer 12

It is the incomplete closure of the eyelid due to paralysis of CN VII

Question 13

Define symlepharon:

Answer 13

An adhesion between the palpebral and bulbar conjunctiva

Question 14

What is this?

Answer 14

pterygium

Question 15

What is the drainage of tears?

Answer 15

• Tears travel to the medial canthus
• It drains into calculi
• Then into the lacrimal sac
• Then into the nasolacrimal sac and into nose

Question 16

What is epiphora?

Answer 16

The obstructtion of the lacrimal gland and it overflowing over the lid

Question 17

What do 5% of neonates develop?

Answer 17

Then a thin membrane that occludes the lacrimal duct and tears and discharging eyes are common

Question 18

What is acute dacryocystitis?

Answer 18

The obstruction of the lacrimal duct which leads to stasis and secondary infection

Question 19

What are the symptoms of acute dacryocystitis?

Answer 19

Pain, redness, swelling and tenderness over lacrimal sac

Epiphora

Question 20

What is the treatment of acute dacryocystititis?

Answer 20

• Local and systemic antibiotics
• Drainage of the abscess
• dacryocystotorhinostomy- making an opening from the lacrimal sac into the nasal cavity

Question 21

What are the clinical symptoms of chronic dacryocystitis?

Answer 21

Epiphora

Swelling of the lacrimal duct

Mucopurulent discharge