Brainscape's Knowledge GenomeTM

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


See full index

Eye Disease > angle closure glaucoma and gonioscopy > Flashcards

angle closure glaucoma and gonioscopy Flashcards

1
Q

which type of patients are most susceptible to getting angle closure glaucoma

A

it is a disease of the over 50’s and is more common in women and hyperopes ( > +8D smaller eyes)

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

what is the cause of an ACG attack

A

when the anterior iris comes into contact (blocks) with the trabecular meshwork or the posterior cornea.
this prevents aqueous outflow causing a sudden rise in IOP and is very painful

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

what produces aqueous and where does the aqueous leave through to get into the anterior chamber

A

aqueous is produced by the ciliary processes and leaves through the canal of schlemm via the venus plexus

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

in an open angle, which route does the aqueous take to leave the eye

A

aqueous moves from posterior to anterior chamber and leaves the eye via the trabecular meshwork

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

what is the principle factor affecting aqueous outflow and why

A

the venous pressure, as there are veins here which can resist aqueous outflow

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

what is iris bombe, and what affects can it have

A

iris bombe is when the iris bows forward and obscures the angle

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

what causes the ability for fluid to leave the eye with age, resulting in increased IOP

A

with age the trabecular meshwork gets blocked and melanin stays in the eye: cells float off the iris e.g. pigment epithelial cells and can drift into the trabecular meshwork, and the macrophages there will phagocytose the pigment epithelial cells, leaving melanin and granule cells in the trabecular meshwork.

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

what is the cause of angle closure

A

an increased pressure in the posterior chamber, pushes the iris forwards blocking the trabecular meshwork, this obscures the angle and there is no way for the aqueous to leave the eye = rise in IOP

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

what does the iris become like when it sticks onto the anterior surface of the lens

A

iris becomes immobile and sluggish

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

what is a indirect goniolens composed of and what are the different versions

A
  • a 90D volk lens
  • mirrors

some can have a single lens and others can be 4 mirror versions

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

what does a mirror from each phase show with a indirect goniolens

A

the opposite angle

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

how do you use a indirect goniolens to assess a patients angle

A
  • place the indirect goniolens on the patient’s eye with lubricating fluid
  • too much pressure can distort the angle, so use gentle pressure
  • if you want to see the superior angle, you need to look through the inferior mirror and you can see the structures within the chamber
  • rotate the mirror to look at all parts of the angle
  • the angles will look slightly magnified
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what part of the indirect goniolens do you need to look through if you wish to view the superior angle on a patient

A

look through the inferior mirror

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

which indirect goniolens is mainly used by ophthalmologists

A

koeppe indirect goniolens

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

list the 4 structures that are found in the anterior chamber angle

A
  • schwalbes line (descements membrane)
  • scleral spur
  • trabecular meshwork (canal of schlemm)
  • ciliary processes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the main thing that you want to see when looking at an angle with a indirect goniolens, which indicates that the angle is open

A

trabecular meshwork (tells you the angle is open)

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

where does schwalbes line sit in the eye

A

at the base of he cornea i.e. descements membrane = where light comes in and meets

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

what structure is anything above the scleral spur

A

trabecular meshwork

19
Q

what structure is fond below the scleral spur

A

ciliary body

20
Q

what is the scleral spur a marker to show

A

to show that the angles are open because above it is the trabecular meshwork

21
Q

why is the scleral spur easy to see

A

because it is white which will always remain white with age

22
Q

which angle is the most open and why should it be viewed first

A

the inferior angle in the widest and should be through the superior mirror with the indirect goniolens
the major landmarks will be able to be viewed in the inferior angle, so you can familiarise yourself with the structures and then move on to see the more narrow angles

23
Q

what colour is the trabecular meshwork usually, and what colour does it become as you age and why is this

A

it is usually pink and becomes more brown as you age as it picks up on the melanin and pigmentation from the iris

24
Q

which structures can be viewed in a grade 4, classified by the schaeffer grading system, when using a indirect goniolens

A

all 4 structures:

  • ciliary body
  • scleral spur
  • trabecular meshwork
  • schwalbes line

characteristic of myopia and aphakia
ciliary body can be seen with ease

25
Q

which structure can be seen with ease in a grade 4

A

ciliary body

26
Q

which structures can be viewed in a grade 3, classified by the schaeffer grading system, when using a indirect goniolens

A
  • scleral spur
  • trabecular meshwork
  • schwalbes line

but not the ciliary body

27
Q

which structures can be viewed in a grade 2, classified by the schaeffer grading system, when using a indirect goniolens

A
  • trabecular meshwork - only can be viewed

you lose view of the scleral spur

28
Q

which structures can be viewed in a grade 1, classified by the schaeffer grading system, when using a indirect goniolens

A
  • schwalbes line - only can be viewed (or maybe the top of trabecular meshwork)
29
Q

which structures can be viewed in a grade 0, classified by the schaeffer grading system, when using a indirect goniolens

A

can’t see anything

30
Q

when viewing the angle on a slit lamp, what indicates that that the angle is closed

A

the beam of the iris will intersect (be continuous with) the beam of the cornea, so there will be no junction/separation between them = iridocorneal contact

31
Q

when viewing the angle on a slit lamp, what indicates that that the angle is not closed

A

the beam of the iris and cornea separates at an interface = no iridocorneal contact

32
Q

how is a grade 0 (closed angle) identified

A

it is a closed angle due to iridocorneal contact and is recognised by the inability to identify the apex of the corneal wedge

33
Q

how does the goniolens distinguish between ‘appositional’ from ‘synechial’ angle closure

A

with appositional angle closure, the goniolens can push the iris away but with synechial (anterior uveitis) angle closure the goniolens cannot push the iris away and the angle will be blocked

34
Q

what structure is the border where light hits descements membrane

A

schwalbes line

35
Q

what is the white band viewed in the angle

A

scleral spur

36
Q

what is found sticking on the scleral spur and trabecular meshwork in angle closure glaucoma

A

iris processes

37
Q

why are hyperopes at a greater risk of having an ACG

A

because there iris curves forwards (as it has a convex shape)

38
Q

what is a concave iris, or myopes at a greater risk of having

A

pigment dispersion syndrome

the iris is big, and pigment is flying off

39
Q

what is found in pigment dispersion syndrome

A

known as the chocolate box line
it is excessive pigment in the trabecular meshwork
other pigment may also be seen settling onto and anterior to schwalbe’s line (onto posterior surface of the cornea) = sampaolesis line

40
Q

what is the name given to excessive on and anterior to schwalbe’s line

A

sampaolesis line

41
Q

what are normal iris blood vessels never attached to and what is the appearance of normal iris blood vessels

A

never attached to structures anterior to the scleral spur
normal blood vessels are thick and have a definite pattern (circumferential or radial), they loop around the base of the iris and always below the scleral spur

42
Q

what is the appearance of normal blood vessels and where do they extend through

A

they are more feathery and have an erratic pattern (does not follow a radial pattern) and also more thinner and are undirectional
they extend past the scleral spur and into the trabecular meshwork

43
Q

what other condition will you look out for if you see a patient with neovascular vessels

A

a px who had a central retinal vein occlusion as they can have a 90 day glaucoma and then neovascular in the anterior chamber

Eye Disease (10 decks)

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