Eye Pathology IV - Lens and Fundus & Neoplasia

Question 1

Answer 1

Question 2

Answer 2

Senile nuclear sclerosis

Question 3

What is senile nuclear sclerosis? (4)

Answer 3

Question 4

What are cataracts and how are they classified? (8)

Answer 4

Question 5

What are the causes of cataracts? (11)

Answer 5

Question 6

Why do dogs get diabetic cataracts but cats don’t? (4)

Answer 6

• 70% of diabetic dogs.
• Lens is a metabolically active tissue, relies on hexokinase pathway to create energy.
• When hexokinase is overwhelmed, glucose is shunted to the sorbitol pathway.
• Cats have low levels of aldose reductase so the sorbitol pathway isn’t used, less sorbitol is produced, so there is no osmotic movement of water into the lens and no hydropic cell rupture, no cataracts formation

Question 7

How do diabetic cataracts arise? (6)

Answer 7

1. Diabetes -> high glucose in aq
2. Hexokinase pathway overwhelmed
3. Glucose shunted to sorbitol pathway
4. Sorbitol accumulates
5. Osmotic movement of water into lens - sucks fluid into lens
6. Hydropic cell rupture - cataract formation as protein denatures within the lens -> changes to lenticular capsule + clefting

Question 8

How are cataracts treated? (8)

Answer 8

Question 9

What is lens subluxation and luxation? (6)

Answer 9

Question 10

What breed of dog encounters spontaneous dislocations of lens luxation?

Answer 10

Middle-aged terrier dogs

Question 11

What are the causes of lens luxation? (7)

Answer 11

Question 12

Answer 12

Rabbit w/ lens luxation due to chronic uveitis + cataracts

Question 13

What are the layers of the retina? (9)

Answer 13

Neurones, glia, vasculature, photoreceptor - from outer nuclear layer towards choroid (rods (low visual acuity) + cones (colour))

Question 14

What is retinal detachment?

Answer 14

Developmental condition

Question 15

What is Collie eye anomaly/choroidal hypoplasia? (4)

Answer 15

Developmental condition

Question 16

What are inherited photoreceptor degenerations and dysplasia - what do they involve, inherited diseases and breeds predisposed? (4)

Answer 16

Developmental condition

Question 17

What is chorioretinitis and its types/causes? (6)

Answer 17

Question 18

What happens when blood is lost at the blood-retina barrier? (3)

Answer 18

Question 19

Answer 19

Question 20

What are the causes of toxic retinopathy? (4)

Answer 20

Question 21

What are the causes of nutritional retinopathy and what conditions do they cause? (7)

Answer 21

Question 22

What is sudden acquired retinal degeneration syndrome? (7)

Answer 22

Question 23

What does systemic hypertension lead to? (5)

Answer 23

Question 24

Answer 24

Question 25

Answer 25

SSC - primary orbital neoplasms, horse - poorly pigmented skin, UV light exposure

Question 26

What are the most reported cases of ocular neoplasms?

Answer 26

Metastatic carcinomas - more likely to get into the bloodstream than sarcomas

Question 27

What are the eyelid and conjunctival neoplasms? (8)

Answer 27

Question 28

Answer 28

Question 29

What is squamous cell carcinoma? 6)

Answer 29

Question 30

Answer 30

Question 31

Answer 31

Question 32

Answer 32

Question 33

Answer 33

Question 34

Answer 34

Question 35

Answer 35

Question 36

What are melanocytic tumours of the eye? (3)

Answer 36