Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Senses > Cataracts - A Practitioner's Perspective > Flashcards

Cataracts - A Practitioner's Perspective Flashcards

1
Q

What is a cataract?

A

opacity of the lens

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

What are the first questions to ask upon suspicion of a cataract?

A
  • is it a cataract?
  • what is the cause?
  • are there other conditions present? If so, how can i be sure? How do I find out?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do you find a cataract?

A
  • examine the eye for opacities (cataracts): the position, presence & size
  • use a mydriatic to examine (especially at the equatorial area)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What type of cataracts are usually stationary?

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

Which cataracts are likely to progress?

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

nuclear sclerosis starts around what age?

A

6-8 years old

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

Where within the eye do cataracts form?

A

on the lens at the centre of rotation posterior to the nucleus

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

What is the general composition of a cataract?

A

35% protein (85% soluble, 15% insoluble)
65% water

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

Composition of cataracts varies by…

A

species, location in the lens, age, and disease

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

the % soluble protein lowers with

A

age & is less in the cataractous lens

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

Cataract formation

A
  • lens protein breaks into polypeptides & amino acids
  • these diffuse thru the lens capsule into the anterior & posterior chamber
  • molecules are not recognised by the immune system so trigger an immune response
  • aka ‘lens-induced uveitis’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Nuclear sclerosis

A

at the lens equator, new lens cells are produced pushing older cells towards the nucleus & become tightly packed w/ reduced soluble fibre

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

What condition?

A

Nuclear sclerosis

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

What condition?

A

Nuclear sclerosis

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

At what age does nuclear sclerosis occur in dogs?

A

6-8 yrs old

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

At what age does nuclear sclerosis occurs in cats?

A

commences at ~12 yrs old

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

Explain the appearance of the nuclear sclerosis

A
  • retina is visible thru the opacity
  • on distant direct ophthalmoscopy - see a refractive ring in the middle of the lens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is important to note about nucelar sclerosis compared to a cataract?

A

in nuclear sclerosis, vision is minimally affected until later on in the dz process

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

What are lens suture line opacities and when do they occur?

A

seen when the pupil is dilated in a young pup under 9 months old
Present at the tips of the anterior & posterior sutures

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

What condition?

A

lens suture line opacities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how are cataracts classified?

A

stage of dvlpmt
position w/i the lens
age of dvlpmt
cause
consistency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the stages of development of a cataract?

A
  1. incipient
  2. immature
  3. mature
  4. hypermature
  5. morgagnian
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the signs of an incipient cataract?

A
  • early focal opacity w/ the sight unaffected
  • Freq. areas of dvlpmt: equatorial cortex, posterior subcapsular polar cotex, Y sutures, posterior cortical cataract
24
Q

What stage of cataract development is present here?

A

incipient stage

25
What stage of development of cataract is this?
immature stage
26
What are the signs of an immature cataract?
* opacity more extensive (more of lens involved) * lens transparency reduced but not lost * tapetal reflection present * retina still visible, reduced vision, degree of vision loss depends on locataion of opacity
27
What stage of cataract development is this?
mature stage
28
What are the clinical signs of a mature cataract?
* lens totally opaque * retina cannot be seen * no tapetal reflection * eye is non-visual
29
What stage of cataract formation is this?
hypermature stage
30
What are signs of a hypermature cataract?
* lens proteins begin to liquefy & leak thru lens capsule causing an immune response --> **lens reduces in size, capsule becomes wrinkled --> inducing 'lens-induced uveitis** * possibly conjunctivitis initially, then uveitis following
31
What are the signs of morgagnian cataract development?
* adv'd degradation of lens proteins --> extensive resorption of cataractous lens * young dogs: cataract may leak away giving return of non-focused vision * Elderly dogs: lens reduces in size but rarely return to vision
32
potential positions of cataracts in the lens
* anterior capsular * anterior subcapsular * cortical * equatorial * nuclear * posterior subcapsular * posterior capsular
33
potential ages of development of cataracts
* congenital * developmental * juvenile * senile * acquired
34
Primary inherited cataract pathogenesis
* most common cause of cataracts in pure-bred dogs * Lab + G. retriever --> posterior subcapsular * American cocker spaniel --> anterior + posterior cortical * When prevalence in breed in > baseline prevalence in crossbreeds
35
Secondary causes of cataract formation
* traumatic * intraocular dz * nutritional * diabetic * toxic * radiation * congenital abnormalities
36
Condition?
micro-ophthalmia
37
Condition?
persistent pupillary membrane
38
condition?
acquired cataract
39
When are cataracts fluid in consistency?
* juvenile cataracts * toxic cataracts
40
When are cataracts soft in consistency?
* rapidly developing cataracts such as in diabetics
41
When are cataracts hard in consistency/
* senile * slow developing inherited cataracts
42
What changes occur in cataract formation?
* lens protein leaks from lens capsule, priming immune response * lens becomes hydrated & swells * uveitis occurs, initially intermittently * iridocorneal drainage angle narrows due to inflammatory debris/fibrosis narrowing the angle & lens bulk pushes towards periphery compromising drainage angle
43
What is seen here?
fibrin in the anterior chamber
44
Signs of uveitis
conjunctivitis miosis or nervous P (less dilated pupil) anterior chamber flare corneal oedema
45
Condition?
lens-induced uveitis
46
Condition?
posterior synechiae
47
ocular examination of cataracts
* collect a detailed Hx * assess the pupillary responses * check the menace responses * perform a detailed examination of the eye
48
Indications of cataract Sx
* significant visual loss
49
Contraindications of Cataract Sx
* functional vision * poor general health (systemic dz) * poor health for anaesthesia * ocular pathologic processes are uncontrolled * retinal pathology (Detachment, degeneration) * uveitis
50
Lens factors affecting cataracts
* lens stability - zonular fibre breakdwon * maturity of the cataract * congenital lens abnormalities (colobomas, lenticonus) * Lens capsular tears (intumescent cataracts, old cataracts - equatorial tears)
51
Condition?
Lens luxation
52
owner/patient factors impacting cataract Sx/txt
* p in good health * p amenable to handling * O able to carry out post-op therapy * cost * ongoing commitment to long-term monitoring
53
Capsulorrhexis
* circular hole made in anterior lens capsule in cataract Sx repair * very important step in procedure
54
Phacoemulsification
* extraction of the lens by ultrasonic vibration, irrigation, aspiration
55
What are the 4 main steps to cataract Sx?
1. capsulorrhexis 2. phacoemulsification 3. irrigation/aspiration 4. lens implantation

Senses (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions