AED - Wet Eye - Week 2

Question 1

How thick is the tear flim? Describe each layer, where it comes from, and how thick they are.

Answer 1

Total thickness is ~7.15μm
Lipid phase - meibomian glands - ~0.1μm
Aqueous phase - lacrimal glands and conjunctiva - ~7μm
Mucoid phase - goblet cells - ~0.05μm

Question 2

What does lid action do to the tear flim?

Answer 2

Pushes it to the drainage sites

Question 3

What do meibomian secretions aid in, and what may it limit?

Answer 3

Aids in spreading and may limit overflow

Question 4

What forms in the eye concerning the tear film?

Answer 4

A lacrimal lake at the margin of the bottom eyelid

Question 5

Describe all the structures of the lacrimal drainage system (5).

Answer 5

At the nasal margin of the eyelids is found two puncta (one for each eyelid) which drains into a canaliculus. These two canaliculi merge nasally to form the common canaliculus.
This drains into the naso-lacrimal sac.
This drains into the naso-lacrimal duct.
At the bottom of this duct is the valve of hasner.

Question 6

What two forces draw tears into the naso-lacrimal sac?

Answer 6

Lid and capillary action

Question 7

Where does the nasolacrimal duct drain to?

Answer 7

The back of the nose

Question 8

What does the valve of hasner prevent?

Answer 8

Backflow

Question 9

Define epiphora.

Answer 9

Tear overflow from the ocular surface

Question 10

List three possible mechanisms of epiphora.

Answer 10

Tear overproduction
Poor tear support / movement
Impaired tear drainage

Question 11

List 3 symptoms of epiphora.

Answer 11

Watery eye
Slight discomfort
Blurred vision

Question 12

What can be said of epiphora if it is worse in cold/windy conditions (2)?

Answer 12

Usually anatomical / obstructive

Question 13

What can be said of epiphora if it is worse in hot/dry conditions (2)?

Answer 13

Usually overproduction / dry eye related

Question 14

List 5 signs of epiphora.

Answer 14

Increased marginal tear prism
Lid anomalies
Drainage blockage
Dry eye
Stenosed (narrowed) puncta

Question 15

List 11 history questions you would ask for epiphora.

Answer 15

Age?
True tear spillage or just poor vision?
When are symptoms worse?
Associated discomfort?
Previous therapy?
Previous CNVII related events, tearing while eating?
Medication?
Red eye/discharge/crusting/allergies?
Pain/swelling?
Surface trauma?
Lid or conj. trauma/surgery/scarring?

Question 16

When doing a slit lamp examination for epiphora, list 5 things to look out for.

Answer 16

Facial characteristics - entropion/ectropion
Normal lid movement
Lacrimal gland swelling
Punctal conformation/patency
Ocular surface condition

Question 17

List 4 techniques (aside from slit lamp) that can be used to assess epiphora.

Answer 17

Lacrimal sac expression (pressure)
Lacrimal lavage (irrigation)
Fluorescein tests
Cotton thread/schirmers test

Question 18

What is the normal range for schirmers test?

Answer 18

≥15 mm

Question 19

List 4 tertiary techniques that can be used to work up an epiphora presentation. Briefly describe the purpose of each test if applicable.

Answer 19

Intranasal examination
X-ray or CT scan - inspection of drainage anatomy
Dacryocystography - radio-opaque dye and x-ray
Dacryoscintigraphy - radiolabel and gamma camera

Question 20

List possible causes of tear overproduction.

Answer 20

Foreign body
Corneal/conjunctival irritation (allergy/infection/dry eye)
Intraocular inflammation
Refractive error (asthenopia)
Nasal irritation/inflammation
Psychological/emotional/environmental
Drug-related
Neural dysfunction/tumour

Question 21

What does management of tear overproduction involve?

Answer 21

Managing the underlying condition

Question 22

List three possible causes of poor tear film support.

Answer 22

Poor apposition of punctae
Obstruction of tear movement (conj. scarring/irregularity)
Lid pumping deficiency
-neuromuscular/ectropion/entropion

Question 23

Define ectropion and entropion.

Answer 23

Ectropion - eversion of the eyelid, away from the eye
Entropion - inversion of the eyelid, towards the eye

Question 24

What is ectropion/entropion commonly due to?

Answer 24

Age-related CT degenerative changes

Question 25

List 4 signs and symptoms of ectropion (aside from lid alignment).

Answer 25

Hyperaemic palpebral conjunctiva Watery/gritty eye Droopy lower eyelid, exposing palpebral conjunctiva Reduced TBUT

Question 26

List two treatment options for ectroption.

Answer 26

Protection of ocular surfaces with tear supplements Surgical correction

Question 27

List 4 signs and symptoms of entropion (aside from lid alignment).

Answer 27

Gritty/watery eye No visible lashes Epithelial disturbances (SPK/ulcers) Hyperaemia of the bulbar conjunctiva

Question 28

List three treatment options for ectroption.

Answer 28

Tear supplements Tape lower lid Surgical correction

Question 29

Can entropion be epilated?

Answer 29

Only if localised

Question 30

Are optometrists generally able to treat underlying causes if epiphora is due to poor tear film movement?

Answer 30

Rarely, although topical therapeutic management with eyedrops may be necessary

Question 31

List 5 obstructions that can result in impaired tear drainage.

Answer 31

Punctae Canaliculae Lacrimal sac Nasolacrimal duct Intranasal obstruction

Question 32

List 6 possible causes ofimpaired tear drainage.

Answer 32

Congenital Trauma Inflammation/scarring Drug-related Infection Tumours

Question 33

What is the general management of impaired tear drainage (2)?

Answer 33

Identify and treat underlying cause as appropriate (referral if necessary) Lacrimal probing and irrigation under topical anaesthesia

Question 34

What can repeated lacrimal probing/irrigation lead to?

Answer 34

Further stenosis

Question 35

Is canaliculitis a common or rare condition? Is it unilateral or bilateral?

Answer 35

Rare, unilateral

Question 36

List 5 signs and symptoms of canaliculitis.

Answer 36

Unilateral epiphora Chronic mucopurulent conjunctivitis that resists treatment Pouting of puncta Chalky granules expressed from canaliculi Lavage indicating canalicular obstruction

Question 37

Consider canaliculitis. If lavage indicates an obstruction, is further probing recommended?

Answer 37

Contraindicated

Question 38

What is the treatment for canaliculitis (2)?

Answer 38

Refer Appropriate antibiotic treatment

Question 39

Define dacryocystitis and whether or not it is unilateral.

Answer 39

Unilateral infection of the lacrimal sac

Question 40

List 4 signs and symptoms of dacryocystitis.

Answer 40

Pain Swelling Cellulitis Mucopurulent discharge

Question 41

What can be said of chronic dacryocystitis? What is it often secondary to?

Answer 41

It may have painless welling and is often secondary to a blockage of the nasolacrimal duct.

Question 42

What is the treatment for dacryocystitis (3)?

Answer 42

Refer Topical and systemic antibiotics Warm compresses

Question 43

Is lacrimal lavage/probing recommended in dacryocystitis? Explain.

Answer 43

Contraindicated due to risk of infection spread

Question 44

List 5 causes of nasolacrimal duct obstruction in children. List the most common one first.

Answer 44

Failure of the valve of hesner to open normally at or near the time of birth Absent punctum Narrow/stenotic system Infection Nasal bone that obstructs the tear duct from entering the nose