Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NOSS > The Abnormal Size and Position of the Eye > Flashcards

The Abnormal Size and Position of the Eye Flashcards

0
Q

What does the prefix phac- pertain to?

A

The lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

What does the prefix cyclo- pertain to?

A

Ciliary body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the prefix kerat- pertain to?

A

The cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the prefix blephar- pertain to?

A

Eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the prefix dacryo- pertain to?

A

Nasolacrimal system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the prefix hyalo- pertain to?

A

The vitreous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which species have a closed orbit?

A

Humans and herbivores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which species have an open orbit?

A

Carnivores and pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the different tissues that fill up the orbit?

A

Eye
Extraocular muscles
Blood vessels, nerves and connective tissue
Fat
Lacrimal gland, gland of TE and zygomatic salivary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can cause space occupying lesions in the orbit?

A

Infection or inflammation as abscesses or cellulitis
Neoplasia (normally malignant)
Specific tissue inflammation - extraocular polymiositis
Parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the clinical signs of space occupying lesions?

A

Globe displacement
Protrusion of the third eyelid
Change in facial symmetry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the characteristics of globe displacement?

A

Frequently dorsolaterally but depends on position of the mass
Frequent anterior component - exophthalmos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why does protrusion of the third eyelid (TE) occur with space occupying lesions?

A

With exophthalmos
Mass displaces orbital fat
Passive third eyelid protrusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is microphthalmia?

A

Small eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the causes of microphthalmia?

A

Small eye from birth usually bilateral and may be accompanied by other ocular defects
Through destruction of the ciliary body as a sequela to inflammation, pthisis bulbi, targeted surgical destruction or chemical ablation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is buphthalmia?

A

Enlarged eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What causes buphthalmia?

A

Increased IOP leading to globe stretching and other changes such as conjunctival and episcleral hyperaemia, corneal oedema, Haab’s striae, Zonular tears, corneal ulcer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Haab’s striae?

A

Stretch marks due to breaks in Descemets membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What cases zonular tears?

A

Overstretching of fibres due to lens displacement

Visible lens equator through pupil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What causes glaucoma?

A

Increased IOP

Damage to the optic nerve head and neural retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 10 layers of the retina?

A

1 epithelial

9 neural with rods, cones and ganglion cells

21
Q

What can cause primary glaucoma?

A

Inherited

Goniodysgenesis = abnormal iridocorneal angle

22
Q

What are the two forms of primary glaucoma?

A

Open angle which is common in people

Closed angel which is common in dogs

23
Q

What can cause secondary glaucoma?

A 
Blood, fibrin, PIFMs, WBCs, Neoplasia
Inflammation - uveitis
Hyphema
Lens luxation
Intra-ocular/metastatic neoplasia
Trauma
24
Q

Which cat breed is predisposed to primary glaucoma?

A

Burmese

25
Q

What can cause secondary glaucoma in cats?

A

Uveitis
FIV, FeLV, FIP, Toxoplasma
Idiopathic

26
Q

What is the relevance of whether glaucoma is primary or secondary?

A

Long vs short term - only one eye affected if secondary and once treated medically might not recur
The other eye - primary will affect both eyes at some point, long term monitoring/treatment will be needed
Breeding - no worry with secondary, advise against if primary

27
Q

What are the clinical signs of glaucoma?

A

Mid-dilated non-responsive pupil +/- aniscoria
Conjunctival and episcleral vessel congestion
+/- vision problems (negative menace/vision maze test)
High IOP on tonometry

28
Q

What are the clinical signs of high to very high IOP?

A 
Corneal oedema
Haab's striae
Cupping of optic nerve head
Lens displacement
Aphakic cresent
Corneal ulceration
29
Q

What is aphakic crescent?

A

Crescent shaped gap due to tear of the zonules and lens movement away from it
Development of crescent between pupil and lens

30
Q

What is the treatment for glaucoma?

A

Control of IOP using anti-hypertensive drops
If secondary treat inflammation, remove the lens from the anterior chamber surgically, remove the eye with problem tumours

31
Q

What are the different anti-hypertensive drops that can be given?

A

Beta-blockers = Timolol
Carbonic anhydrase inhibitors = Dorzolamide
Prostaglandin analogue = Latanoprost

32
Q

What is the rationale behind using beta-blockers to treat glaucoma?

A

Reduce production of aqueous
Give BID
Weak but cardiac and respiratory effect

33
Q

What is the rationale behind using carbonic anhydrase inhibitors to treat glaucoma?

A

Reduce the production of aqueous
Block CA enzyme in the ciliary body epithelium
Given BID to TID
Strong, work well in combination with beta-blocker (Cosopt)
Works in cats and horses

34
Q

What is the rationale behind using prostaglandin analogues to treat glaucoma?

A

Increases the outflow of humour
Given SID in the evenings or BID
Strongest but can cause inflammation
Doesn’t work in cats, works in horses

35
Q

How is glaucoma managed?

A

Hospitalisation with serial measurement of IOP every 3 hours to plot a curve

36
Q

What are the clinical signs of lens luxation?

A 
Phacodeonesis-Iridonesis - lens and iris wobbling
Anterior presentation of vitreous
Deep anterior chamber
Anterior or posterior luxation
An increase in IOP
37
Q

What are the causes of posterior luxation?

A

Cataract formation
Lens induced uveitis
Lens adhesion to the retina

38
Q

What are the consequences to anterior lens luxation?

A

Pupil block glaucoma

Damage to the corneal endothelium - central corneal oedema

39
Q

Which breeds are affected by inherited lens luxation?

A

Terrier breeds

Lancanshire heelers, Chinese crested, Australian Cattle Dog, Volpino Italiano

40
Q

What pathology does pupil block glaucoma and other acute increase in IOP cause?

A

Damage to retinal ganglion cells
Damage to optic nerve head
Damage to blood vessels possible

41
Q

What is the treatment for pupil block glaucoma and other acute increases in IOP?

A

Immediate removal of the lens in anterior luxation

Medical therapy to control future IOP spikes

42
Q

What is used in the medical management of lens luxation?

A

Xalatoan - PG analogue (causes marked miosis)

43
Q

What is the name of the surgical treatment for lens luxation?

A

Endolaser cyclophtocoagulation

44
Q

What are the three typical signs of retrobulbar disease?

A

Displacement of globe, 3rd eyelid protrusion, change in facial symmetry, corneal ulcer

45
Q

What causes aphakic crescent?

A

Increased IOP, zonules break, lens displaces, see equator

46
Q

What test would confirm high IOP?

A

Tonometry

47
Q

Is glaucoma painful?

A

Yes

48
Q

Does glaucoma affect vision?

A

Yes as it damages the retina and optic nerve head

49
Q

What is an IOP curve?

A

Measurement of the IOP every 3 hours and plotted on a graph to see when it spikes

NOSS (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions