Y4 Opthalmology Rvc Finals

Front 1

Describe the FIVE layers of the cornea

Back 1

- transparent covering continuous with conjunctiva
- Bowman's membrane (basement membrane of surface epithelium)
- transparent fibrous layer
- Descemet's membrane (basement membrane of endothelium)
- endothelium

Front 2

What is the route of aqueous humour within the eye?

Back 2

Produced by the ciliary body, fills the anterior chamber before draining via the iridocorneal drainage angle to the scleral veins

Front 3

Where is vitreous humour produced?

Back 3

Produced by the ciliary body, stored in the posterior chamber and not replaced.

Front 4

Where are optic nerve cell bodies?

Back 4

Within the retina (it has no ganglion)

Front 5

Name the THREE layers of lacrimal fluid, and say where they are produced

Back 5

Mucus layer (conjunctival goblet cells)
Aqueous layer (lacrimal glands)
Oily layer (sebaceous tarsal glands)

Front 6

What FOUR drug categories are used in medical management of glaucoma?

Back 6

- aqueous formation suppressors
- miotics
- uveoscleral outflow enhancers
- hyperosmotic agents (do not work in chronic glaucoma as the blood-aqueous barrier breaks down)

Front 7

Name THREE types of aqueous formation suppressor used in medical management of glaucoma

Back 7

- carbonic anhydrase inhibitors
- beta blockers
- alpha-2 agonists

Front 8

Name TWO drug categories that have miotic effects

Back 8

- parasympathomimetics
- acetylcholisnesterase inhibitors

Front 9

Name TWO types of dug that may be used to enhance uveosceral outflow

Back 9

- alpha-2 agonists
- PGF 2-alpha analogues

Front 10

Name THREE hyperosmotic agents that may be used to medically manage acute glaucoma

Back 10

- mannitol
- glycerol
- urea

Front 11

What drug is used to dilate the pupils? Why does it work?

Back 11

Tropicamide is used. It is a parasympatholytic.

Front 12

What is the normal value of Schirmer tear test?

Back 12

More than 10mm/minute in all species

Front 13

What is normal intraocular pressure?

Back 13

15-25mmHg

Front 14

What 4 things invalidate tonometry?

Back 14

- patient struggles
- tonometer not vertical
- corneal curvature not constant
- corneal oedema present

Front 15

What rate do interstitial corneal vessels grow at?

Back 15

Take 3 days to be induced then grow at 1mm/day

Numerous straight vessels extend inward from the limbus as a rim

Front 16

What causes interstitial corneal vascularisation?

Back 16

severe deep keratitis or anterior uveitis

Front 17

What anaesthetic agent is applied topically to the eye?

Back 17

Proxymetacaine

Front 18

How should ocular cytology be interpreted?

Back 18

Neutrophils - bacterial infection
Lymphocytes - viral infection

Front 19

Describe how tear break-up time can be measured
What is a normal value?

Back 19

Fluorescein stain the eye, then hold eyelids closed, reopen and wait for appearance of a dark spot
Cats 12-21s, dogs >20s

Front 20

What causes superficial corneal vascularisation?

Back 20

Chronic superficial irritation

Front 21

What are the THREE layers of tear film? What cell type produces each layer?

Back 21

Mucin layer (goblet cells)
Aqueous layer (lacrimal glands)
Lipid layer (meibomian sebaceous glands)

Front 22

What causes heterochromia?

Back 22

Chronic iridal irritation

Front 23

What is the collarette?

Back 23

Divides iris into concentric zones

Front 24

What is the function of the granula iridica?

Back 24

Also called corpora nigra
Shade the retina in LA

Front 25

Give SIX differentials for dyscoria

Back 25

Iris hypoplasia
Coloboma (at 6 o'clock position due to failure of closure of optic cup)
Atrophy (aging change)
Persistent pupillary membranes
Synechiae
Preiridal fibrovascular membranes

Front 26

Give FOUR causes of uveal masses

Back 26

Cysts (due to inflammation or age, transilluminate)
Lymphoma (cats - may see mass on iris, anterior uveitis more common presentation)
Feline diffuse iris melanoma (focal hyperpigmentation that coalesces and progresses to glaucoma)
Canine anterior uveal melanocytoma (slow-growing in iris or ciliary body)

Front 27

Give TWO causes of mydriasis

Back 27

Glaucoma
Optic nerve deficits

Front 28

Give THREE differentials for miosis

Back 28

Horner's syndrome
Uveitis
Organophosphate toxicity

Front 29

A rabbit presents with dacrocystitis. What is your top differential?

Back 29

Dental disease

Front 30

What is distichiasis?
How is it managed?

Back 30

Impingement of the cilia on the cornea
Cryosurgical removal

Front 31

What name is given to the condition where cilia are at 90 degrees to and impinging on the corneal surface?

Back 31

Ectopic cilia

Front 32

What name is given to angling of the eyelids onto the palpebral surface?

Back 32

Trichiasis

Front 33

Give SEVEN differentials for blepharitis

Back 33

Sarcoptes
Demodex
Staphylococcal infection
Microsporum
Trichophyton
Pemphigus
Immune-mediate uveodermatologic syndrome (Japanese akitas)

Front 34

What is a chalazion?
How is it treated?

Back 34

A meibomian gland granuloma
Drain surgically

Front 35

What is a hordeum?
How is it treated?

Back 35

An infected eyelash sebaceous gland.
Drain surgically

Front 36

What are the TWO regions of the retina?

Back 36

Pigment epithelium outermost (provides metabolites for phototransduction)
Neuroretina innermost (phototransduction)

Front 37

What is the normal appearance of retinal vasculature in the dog?
In the cat?

Back 37

Dog - 3 or 4 veins
Cat - inverted 'Y'

Front 38

What is the most likely cause of tapetal hyperreflectivity and melanin pigmentation?

Back 38

Chorioretinitis

Front 39

A dog presents with sudden onset blindness and absent PLR. What is your top differential?
What do you expect to see on fundic exam?

Back 39

Idiopathic optic neuritis
Fundic exam may be normal or optic disc oedema/haemorrhage

Front 40

What aetiology do you suspect if there is optic nerve and retinal degeneration?

Back 40

Avitaminosis A

Front 41

What aetiology do you suspect is there is lipopigment accumulation in the tapetum?

Back 41

Avitaminosis E

Front 42

A 7-year old dog presents with sudden-onset blindness and normal fundus, but the retina degenerates over the next few days. What is your top differential?
What is your suspected aetiology?

Back 42

Canine SARD (sudden acwuired retinal degeneration)
May be Cushingoid or toxic aetiology

Front 43

How is retinal detachment managed?
What is the prognosis?

Back 43

Corticosteroid and diuretic
Prognosis fair but worsens with duration of detachment

Front 44

Name the THREE signs of Collie Eye Anomaly

Back 44

Choroidal hypoplasia (pale patch lateral to optic disc, later obscured by melanin)
Coloboma
Neuroretinal detachment (may not be present)

Front 45

Why does glaucoma occur?

Back 45

Inadequate aqueous humour drainage at the iridocorneal angle
May be congenital or secondary to synechiae formation