the cornea

Question 1

pathophysiological features of the cornea?

Answer 1

1. oedema
2. pigmentation
3. ulceration
4. infiltration
5. scar formation

Question 2

what is the cause of pigmentation?

Answer 2

chronic corneal irritation, desiccation, exposition

Question 3

features of leucocyte, granulocyte infiltration?

Answer 3

infection

stroma abscessation

Question 4

features of eosinophilic infiltration?

Answer 4

allergen, antigen

Question 5

what is kerectasia or keratectasia?

Answer 5

severe granulation dur to chronic irritation

Question 6

list the diseases of the cornea?

Answer 6

1. corneal dermatoid

2. keratitis

Question 7

aetiology of keratitis?

Answer 7

1. infectious
2. traumatic
3. allergic
4. due to mechanical or chemical irritation, desiccation, innervation abnormalities, chronic corneal oedema
5. associated to systemic disease
6. unknown

Question 8

name the 5 types of corneal ulcers?

Answer 8

1. uncomplicated, superficial corneal ulcer
2. indolent (non healing), superficial corneal ulcer
3. non melting (superficial stroma, midstromal, deepstromal)
4. melting corneal ulcer
5. descemtocele

Question 9

list the clinical signs of uncomplicated, superficial corneal ulcer?

Answer 9

mild lacrimation
blepharospasmus
perifocal oedema
if the upper stroma is exposed - fluorescein positive

Question 10

treatment options for uncomplicated, superficial corneal ulcers?

Answer 10

elimination of the cause 
antibiotic eye drops
eye lubricants 
topical vitamins 
normally heals within 10-14 days

Question 11

describe the aetiology of indolent (non healing), superficial corneal ulcers?

Answer 11

heals slowly or poorly (or no improvement at all), tens to restart
spontaneous separation of the stroma and epithelium
hereditary (boxer ulcer)

Question 12

signs of indolent corneal ulcer?

Answer 12

lacrimation 
blepharospasm 
undetermined lip or rolled up exfoliation of the epithelium 
stroma is exposed 
fluorescein positive 
vascularisation is rarely stimulated

Question 13

treatment for indolent corneal ulcers?

Answer 13

surgery:

• grid opr multipuncture keratotomy (not in cats)
• diamond burr debridement (DBD)
• superficial keratectomy (+ third eyelid flap, bandage, contact lens)

healing of the ulcer, scar formation - however can reoccur

Question 14

medical therapy is contraindicated in indolent ulcers, true/ false?

Answer 14

true

Question 15

how long to leave third eyelid fixation after DBD?

Answer 15

2 weeks

Question 16

signs of a non-melting deep corneal ulcer?

Answer 16

Pain, enophthalmos, prolapse of the third eyelid, blepharospasm, miosis, constriction of ciliary body
mucopurulent, purulent discharge
deep excavation in the cornea with well expressed edge
fluorescein positive
perifocal of diffuse corneal oedema
pigmentation

Question 17

treatment of Non melting deep corneal ulcer?

Answer 17

elimination of the cause 
medical
- Atropine 
- antibiotics 
- serum 

surgery

Question 18

pathophysiology of melting corneal ulcer?

Answer 18

potential danger to eye globe
proteases, elastase and colligenases produced from:
- leucocytes
- destroyed corneal epithelial cells and fibroblasts
- bacteria
irregular and excessive exogenic balance of enzymes
dissolving the stroma –> melting the cornea

Question 19

clinical signs of deep melting ulcer?

Answer 19

severe pain
purulent discharge 
diffuse corneal oedema 
corneal infiltration 
greyish-white, gelatine like material at the base and edge of the ulcer 
secondary uveitis, hypopyon 
keratomalacia

Question 20

treatment of deep melting ulcers?

Answer 20

emergency intervention 
elimination of the cause 
medical therapy alone is contraindicated 
surgery 
- elimination of enzymes 
- corneal cross-linking surgery

Question 21

clinical signs of descemetocele deep ulcer?

Answer 21

bottom of the ulcer is formed by the descent’s membrane

• dark and smooth
• contains numerous elastic fibres

Pathognomic ring like staining of fluorescein dye

Question 22

treatment of descemetocele deep ulcer?

Answer 22

emergency intervention
elimination of the cause
medical therapy contraindicated
surgery is only viable treatment ( suturing if descemetocele is small)

Question 23

definition of non-ulcerative keratitis?

Answer 23

inflammation of the superficial or deeper layers of the cornea without ulcer formation

Question 24

list the non-ulcerative type of keratitis?

Answer 24

Uberreiter’s syndrome

Question 25

aetiology of Uberreiter’s syndrome?

Answer 25

Unknown, autoimmune
role of UV and viruses
Proliferation of epithelial cels + infiltration of the superficial stroma by plasma cells and lymphocytes + vascularisation, lipid deposits, pigmentation, oedema and scar formation

Question 26

which breed are predisposed to Uberreiter’s syndrome?

Answer 26

German shepherds

Question 27

clinical signs of Uberreiter’s syndrome?

Answer 27

First: temporal (nasal) inferior corneal quadrant will be opaque
the opacity gradually moves centrally, finally the whole cornea may be involved
the opacity: reddish-grey or black
Fluorescein negative

Question 28

treatment of Uberreiter’s syndrome?

Answer 28

incurable
medical:
- subconjunctival and topical steroids
- topical cyclosporin, tacrolimus

Protect against UV light

surgical:
- superficial keratectomy

Question 29

treatment of superficial and deep injuries without perforation?

Answer 29

similar to ulcer therapy

medical or surgical

Question 30

treatment of perforation, laceration?

Answer 30

to save the eye with surgery (conjunctival grafts, direct suturing)
to remove the eye (enucleation)

Question 31

supporting methods to eye treatment?

Answer 31

third eyelid flap, BCL, physical protection

Question 32

aftercare of eye treatment?

Answer 32

topical atropine
topical antibiotics
systemic NSAIDs
systemic antibiotics

Question 33

w

hen would you perform a grid keratotomy?

Answer 33

ONLY in small animals

ONLY non-melting ulcers

Question 34

when is pedicle conjunctival graft transposition carried out?

Answer 34

for melting and non melting deep corneal ulcers

Question 35

when can you directly suture descemetocele?

Answer 35

small descemetoceles only

max. 3mm in diameter