Canine/Feline Cornea

Question 1

What are the parts of clinical assessment of canine/feline cornea?

Answer 1

• previous Hx
• eyelid anatomy
• facial anatomy/globe size
• tear prod’n - qlty/qty
• breed
• clin disorders
• contralateral eye

Question 2

What is the ultimate aid to the eye?

Answer 2

Slit lamp biomicroscope

Question 3

White colour in the cornea?

Answer 3

oedema, lipid, scarring, infectious agent

Question 4

Red colour change in cornea?

Answer 4

neovascularisation, stromal haemorrhage, symlepharon, neoplasia

Question 5

Pigmented lesion colour change in cornea?

Answer 5

superficial benign melanin, sequestrum, uveal pigment - usually deep

Question 6

What are categories of corneal lesions?

Answer 6

• congenital non-inflammatory
• acq’d non-inflammatory
• non-ulcerative inflammatory dz
• ulcerative inflammatory dz

Question 7

congenital non-inflammatory corneal lesions

Answer 7

persistent pupillary membranes

Question 8

acquired non-inflammatory corneal lesions

Answer 8

lipid keratopathy, band keratopathy, corneal endothelial dystrophy

Question 9

Non-ulcerative inflammatory dz corneal lesions

Answer 9

Superficial keratitis –> mechanical, infectious, pannus, eosinophilic keratitis, pigmentary keratitis, herpes virus keratitis

Question 10

Ulcerative inflammatory dz corneal lesions

Answer 10

Physical, chemical, infectious, dry eye, neurotropic, immunological, metabolic

Question 11

What are some important instruments needed?

Answer 11

• small suture needles
• micro-pointed speculated needles if suturing cornea
• binocular magnifying loupe
• common ophthalmology sutures (Vicryl 4/0, 6/0, 8/0, 9/0)

Question 12

What is condition is likely present in this dog? What is it?

Answer 12

Lagophthalmos - unable to close the eyelids; dry eyes in the middle of eye b/c cannot close completely; poor healing

Question 13

Pugs commonly have this condition. what is it?

Answer 13

• result of exposure dryness
• inflamed
• BVs come on
• pigment on cornea
• wide open eyes, poor blink - cornea unstable, difficult to heal

Question 14

What condition is?

Answer 14

• dry eye - not enough tears
• high inflammation w/ time

Question 15

What condition?

Answer 15

focal oedema - inside of cornea not controlling fluid in/out of cornea consistently, integrity of inner film like pump, like a little circle, bilateral

Question 16

What condition?

Answer 16

• fat crystals, different shapes possible
• Mature to point & stabilise
• Genetic predisposition, often bilateral

Question 17

What condition?

Answer 17

• Eyelid hair

Question 18

What condition?

Answer 18

• Feline Keratitis
• Caused by herpes, activated in stress/immunocompetency

Question 19

What condition?

Answer 19

• Corneal Sequestrum
• cats & herpes
• dead/dying in cornea rise to surface
• excise & graft commonly needed

Question 20

What condition? How is it treating?

Answer 20

Corneal FB
Txt: remove - do not grasp. Use needle/blade at 90 degrees to FB & milk out; hole self-selas usually; medicate for uveitis

Question 21

Clinical Signs of Corneal ulceration

Answer 21

• blepharospasm
• pain
• epiphora
• aqueous flare
• inflamm cells in anterior chamber
• hypopyon
• conjunctivitis/episcleritis
• corneal oedema
• miosis

Question 22

How to dx an ulcer?

Answer 22

appearance
fluorescein stain
eye may not open - use topical anaesthetic

Question 23

What level of corneal ulceration is this?

Answer 23

shallow

Question 24

What level of corneal ulcer is this?

Answer 24

30% depth

Question 25

What depth of corneal ulcer is this?

Answer 25

95% depth

Question 26

What is present here?

Answer 26

Descemetocoele - 95%

Question 27

What condition?

Answer 27

corneal ulcer - perforated

Question 28

What condition?

Answer 28

Corneal laceration

Question 29

What anti-microbial therapy can be used w/ Staph & strep?

Answer 29

Fluoroquinolones

Question 30

What anti-microbial therapy should be used w/ gram-neg rods (pseudomonas e.g.)

Answer 30

* gentamycin * polymyxin B * fluoroquinolones

Question 31

What medications can be used w/ chlamydia, mycoplasma?

Answer 31

* tetracycline * chloroamphenicol

Question 32

What systemic antivirals can be used for corneal issues?

Answer 32

Famciclovir

Question 33

What topical antiviral treatment can be used for corneal issues?

Answer 33

Ganciclovir

Question 34

What anti-collagenase therapy can be used for corneal txt?

Answer 34

* for melting corneal ulcer + topical/systemic tetracyclines * Serum, EDTA

Question 35

What is collagenase?

Answer 35

produced by bacteria esp gram negs like Pseudomonas

Question 36

Pain relief for corneal pain?

Answer 36

* ciliary muscle spasm - Cycloplegics = Atropine 1% drops * NSAIDs * Corneal lubrication * Vet bandage lens * Nictitans flap *

Question 37

Always remember to treat...

Answer 37

uveitis

Question 38

if you have an ulcer, you can preseume you have...

Answer 38

uveitis

Question 39

Uveitis is

Answer 39

painful

Question 40

Uveitis leads to...

Answer 40

* posterior synechiae * intraocular inflammation * Ocular hypertension

Question 41

Uveitis can have

Answer 41

* an inflamed colour change * haze

Question 42

Clinical Signs of Uveitis

Answer 42

* resistance to mydriatics * lowered IOP * anterior/posterior synechiae * swollen or dull iris appearance * increased pigmentation of the iris * vitreal haze * retinal oedema * aqueous lipid

Question 43

How do you control inflammation of mild uveitis?

Answer 43

topical corticosteroids 0.1% dexamethasone 1% prednisolone

Question 44

How do you control inflammation of moderate uveitis?

Answer 44

* topical corticosteroids * systemic prednisolone * atropine drops

Question 45

How do you control inflammation in severe uveitis?

Answer 45

topical corticosteroids systemic prednisolone atropine drops severe pain: add systemic analgesic

Question 46

Mild uveitis is marked by what signs?

Answer 46

conjunctivitis mininmum aqueous flare +/- miosis hypotony

Question 47

Moderate uveitis is marked with what clinical signs?

Answer 47

conjunctivitis obvious aqueous flare +/- miosis hypotony

Question 48

Severe uveitis has what clinical signs?

Answer 48

conjunctivitis marked aqueous flare miosis hypotony

Question 49

What is the protocol for a re-exam of a corneal ulcer?

Answer 49

Superficial corneal ulcers: * non-brachys: 1 wk * brachys 48-72 hrs All other corneal ulcers: 48-72 hrs

Question 50

When can you use a nictitans flap?

Answer 50

* shallow ulcers

Question 51

more involved types of txt for corneal ulcer?

Answer 51

* nictitans flap * vet bandage lens * Sx * Iontophoresis

Question 52

What is shown here?

Answer 52

Nictitans flap

Question 53

What is shown here?

Answer 53

Vet bandage lens

Question 54

What is present here?

Answer 54

Superficial corneal ulcer w/ fluorescein stain

Question 55

What is commonly used as topical anaesthetic to relax an eye for an eye exam?

Answer 55

Tetracaine 1% (proparacaine)

Question 56

What is present here?

Answer 56

Granulation tissue on an ulcer causing vascularisation & scar tissue

Question 57

What txt would you use for a broad melting ulcer?

Answer 57

Conjunctival pedicle graft

Question 58

What is present here?

Answer 58

Corneo-conjunctival graft

Question 59

What is present?

Answer 59

A cell graft (pig bladder membrane) * not infected ulcer * sutured in place 8-9/0 Vicryl

Question 60

What txt is here?

Answer 60

Amniotic membrane graft

Question 61

What txt is here?

Answer 61

Iontophoresis

Question 62

What txt is here?

Answer 62

Corneal cross linkage