The wet eye

Question 1

What is epiphora?

Answer 1

overflow of tears onto the face
- increased tearing
- drainage problems

Question 2

What nerve stimulates increased tearing and what might cause that?

Answer 2

trigeminal nerve CN 5

corneal ulver, FB
aka irritation/pain

Question 3

What could cause drainage problems in the eye?

Answer 3

eyelid abnormality: entropion/ectropion
prolapse of the gland of the nictitans membrane
blockage of the nasolacrimal system

Question 4

What are the 3 components of tears and what structure are they from?

Answer 4

lipid: meibomian/tarsal glands
aqueous: lacrimal gland and accessory lacrimal gland
mucin: goblet cells in the conjunctiva

Question 5

What is the role of each 3 component in tears?

Answer 5

lipid: reduces evaporation of tears
aqueous: nourishes ocular surface
mucin: helps aqueous part adhere to corneal surface

Question 6

In what order do tears flow in what structures?

Answer 6

1. lacrimal puncta
2. canaliculi
3. lacrimal sac
4. nasolacrimal duct
5. nasal punctum

Question 7

What is the difference between trichiasis, distichiasis and ectopic cilia?

Answer 7

trichiasis: normal hairs from normal location touching the cornea
distichiasis: hair growing out of mybomeian glands and touching cornea
ectopic cilia: hairs growing on inner conjunctiva and constantly rubbing on the eye surface

Question 8

When can a gp consider an eyelid mass removal?

Answer 8

if it affects less than 1/3 of eyelid margin
if more: consider referral

Question 9

What is euryblepharon?

Answer 9

also known as macroblepharon
bleph = eyelid

enlarged eyelids causing more white eye

Question 10

What is entropion?

Answer 10

When the eyelid rolls in towards the surface of the eye causing hair and skin to rub onto the cornea

can’t follow the non-haired part of the eyelid due to it being rolled

Question 11

What are potential causes for entropion?

Answer 11

after eyelids opening at 14 days
breed related: eyelid and extreme skull conformations
acquired: elderly, laxity of tissues and loss of retrobulbar fat

Question 12

What is blepharospasm?

Answer 12

the eye is closed tightly due to pain

can lead ti secondary entropion: spastic entropion`

Question 13

How can we treat blepharospasm/spastic entropion?

Answer 13

apply 1 drop of proxymetacaine (topical anaesthetic)
if entropion persists: needs surgical correction
if entropion disappears: investigate source of ophtalmic pain

Question 14

What is eyelid coloboma/agenesis?

Answer 14

abnormal development of eyelid or parts of eyelid missing

Question 15

What is diamond eye?

Answer 15

combination of euryblepharon and entropion
esp. in large breed dogs

Question 16

What are potential causes of a nasolacrimal blockage?

Answer 16

unilateral chronic discharge
mass effect from orbital or nasal disease
dacryocystitis (FB or idiopathic)

Question 17

How can we test if an animal has nasolacrimal blockage?

Answer 17

using the jones test: fluorescein and wait to see if stain appears at the nostrils (can be false negative)

if negative: imaging and potential flushing of nasolacrimal system