Eye Pathology II

Question 1

What does a red corneal opacity mean?

Answer 1

Blood Vessels

Question 2

What does a blue corneal opacity mean?

Answer 2

Oedema

Question 3

What does a Crystalline White Corneal Opacity Mean?

Answer 3

lipids

Question 4

What does a black corneal opacity mean?

Answer 4

Pigment

Question 5

What is a ‘melting ulcer’ ?

Answer 5

rapid degredation and liquefaction of corneal tissue
either from
* bacterial/ fungal infection
* Inflammatory cells from tear film

Also Called Keratomalacia

Question 6

What is Descemetocele?

Answer 6

Liquefaction of the corneum leads to the underlying Descemets membrane being pushed forward

Question 7

What are the four clinical signs of Corneal Ulceration?

Answer 7

1. Pain- either inflammatory mediators or Blepharospasm
2. Conjunctival Hyperaemia- recruitment of leukocytes
3. Corneal oedema- loss of epithelium (ingress of water)
4. Corneal neovascularisation

blepharospasm= increased blinking rate

Question 8

What are two examples of internal ocular disease

corneal oedema

Answer 8

• Glaucoma
• Uveitis

Question 9

What is Blepharospasm?

Answer 9

Involuntary tight closing of the eyelids

Question 10

What is lipid keratopathy?

Answer 10

Crystalline dense white deposit in the middle of the cornea

Question 11

What are corneal dystrophies subclassified as?

Answer 11

1. Epithelial
2. Stromal
3. Endothelial

Question 12

In what dog species is central corneal lipidosis most common in?

Answer 12

Cavaliers, Boxers, Huskies

Question 13

What is Central Corneal lipidosis?

Answer 13

Excessive accumulation of lipids in corneal fibroblasts

Question 14

What are corneal deposits usually secondary to?

Answer 14

Metabolic Disease

hyperadrenocorticism, DM, hypothyroidism

Question 15

What is Feline Corneal Sequestrum usually recognised as?

Answer 15

discrete orange-brown discolouration of the central cornea, affecting one or both eyes

black pigment is absorbed from the feline tear-film

Question 16

In what two dog breeds is SCEED common in?

Answer 16

Boxers and Pembroke Corgis

Question 17

In what dog breed is Pannus Keratitis Most Common in?

e.g chronic superficial keratitis

Answer 17

GSD

Question 18

What does a pannus keratitis lesion mainly look like?

Answer 18

• Superficial Corneal vascularisation
• infiltration of granulation tissue, lymphocytes and plasma cells
• Pigmentation

Question 19

What does Feline eosinophillic keratitis look like?

Answer 19

• Can be either Unilateral or Bilateral
• Eosinophils are in dense white plaques
• Neovascularisation

Question 20

What is Glaucoma?

Answer 20

Forcing fluid into the cornea

Question 21

What is Uveitis?

Answer 21

Inflammation of the endothelial cells

Question 22

What is Ulceration?

Answer 22

When there is loss of the waterproof barrier

Question 23

What happens if the endothelial pump in the corneal endothelium fails?

Answer 23

• No pumping fluid from the cornea into the anterior chamber to maintain the partially dehydrated state of the cornea
• Increased intraocular pressure
• Cell death/ inflammation

Question 24

What four things may cause corneal oedema?

Answer 24

• Endothelial cell loss
• Internal ocular disease (glaucoma, uveitis)
• Ulceration- loss of waterproof barrier
• Limbal disease

Question 25

What is the affect of stromal liquefaction that reaches descemets membrane?

Answer 25

results in forward bulging | stroma may be lost completely

Question 26

What are the common causes of corneal ulcers?

Answer 26

* Developmental (irritation/ poor corneal health) * Inflammation and infection (immune-mediated KCS) * Dry eye * Traumatic

Question 27

What are the diagostic processes for corneal ulcers?

Answer 27

* Magnification/ illumination * Fluorescein staining for a corneal ulcer * Schirmer tear test to rule out KCS

Question 28

What is the definition of a corneal dystrophy?

Answer 28

Defects in the structure and function of one or more corneal components not triggered by injury or systemic disease

Question 29

What is SCCED characterised by?

Answer 29

Shallow central corneal erosion with a scant oedema and no vascularisation

Question 30

What factors are implicated in pannus keratitis?

Answer 30

* Age * Breed * Gender * Environmental factors (sunlight exposure)

Question 31

What occurs in the latent phase of rebuilding epithelial cells over the stroma?

Answer 31

* Apoptosis of cells damaged by wound stimulus * Fribronectin polymerases provide provisional anchoring to the wound bed * reduction in adhesion of basal cells to the basement membrane

Question 32

What occurs in the migration phase of rebuilding epithelial cells over the stroma?

Answer 32

* Leading edge cells flatten out over the wound area and develop filopedia * migration of entire epithelial sheet over the wound bed * no cell division at this stage

Question 33

What occurs in the proliferation phase of rebuilding epithelial cells over the stroma?

Answer 33

* Cells at the periphery of the cornea undrgo mitotic divison whilst the wound bed is migrated over * Transformation of the basal layers of stratified epithelium and eventually squamous cells * basement membrane remodelling

Question 34

What are the three examples of corneal dystrophy?

Answer 34

* Corneal lipid and crystalline deposits * Corneal deposits secondary to corneal insult * corneal depositis secondary to metabolic disease

Question 35

What are two examples of corneal degeneration?

Answer 35

* Felien corneal sequestrum * SCCED

Question 36

What are the two examples of keratitis?

Answer 36

* Chronic/ Superficial keratitis * Feline eosinophillic keratitis