Brainscape's Knowledge GenomeTM

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


See full index

year 2 neuro - Robbie > Common conditions of the eye > Flashcards

Common conditions of the eye Flashcards

1
Q

What is a hordeolum?

A

A hordeolum is a common disorder of the eyelid. It is an acute focal infection (usually staphylococcal) involving either the glands of Zeis or, less frequently, the meibomian glands

they can appear externally and internally

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

a

A

superior rectus

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

b

A

lateral rectus

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

c

A

inferior rectus

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

d

A

inferior oblique

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

e

A

medial rectus

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

f

A

superior oblique

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

What is conjunctiva

A

thin vascular membrane that covers inner surface of eyelids and loops back over sclera.

Does not cover the cornea

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

What is conjunctivitis, symptoms and treatment?

A

Self-limiting bacterial or viral infection of the conjunctiva

Red, watering eyes, discharge

No loss of vision as long as infection does not spread to cornea

Rx – antibiotic eye drops if likely to be bacterial

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

What are the 2 types of stye or hordeolum?

A

External – affecting the sebaceous glands of an eyelash

Internal – affecting the meibomian glands

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

Describe the histology of the cornea (5 layers)?

A
  1. Epithelium - stratified squamous non-keratinised
  2. Bowman’s membrane (basement membrane of corneal epithelium)
  3. Stroma - regularly arranged collagen, no blood vessels
  4. Descemet’s layer
  5. Endothelium – single layer (normal - 2500 cells/mm2) - shown by arrow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are 2 types of pathology of the cornea?

A
  1. Inflammatory – eg: corneal ulcers
  2. Non-inflammatory – eg: dystrophies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can corneal pathologies commonly lead to?

A

Corneal pathologies frequently lead to opacification of the cornea. This might need to be treated by corneal transplant - Keratoplasty

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

What may cause corneal ulcers?

A

Infectious - Viral/ bacterial/ fungal infection of cornea. Needs aggressive management to prevent spread, scarring

Non-infectious ulcers due to trauma, corneal degenerations or dystrophy

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

Non- Inflammatory dystrophies and degenerations are a group of diseases affecting the cornea which are what?

A
  1. Bilateral
  2. Opacifying
  3. Non – inflammatory
  4. Mostly genetically determined
  5. Sometimes due to accumulation of substances such as lipids within the cornea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the lcinical presentation of non- inflammatory dystrophies and degenerations

A

First to fourth decade

Most commonly - decreased vision

Start in one of the layers of the cornea and spread to the others

17
Q

Is a corneal transplant easier or harder to carry out and why?

A

The avascularity of the cornea is of benefit to surgeons when performing a graft surgery as it means there is a lesser chance of foreign antigens from a corneal graft being recognised by the recipient, so lesser chance of a graft rejection

This has lead researchers to believe that the cornea is an “immune-privileged” site

(remember there are no lymphatics draining the eyeball; though lymph drains the eyelids)

18
Q

What is the most common disease affecting the eye?

A

cataract

19
Q

What is a cataract?

A

lens opacification

20
Q

Why do cataracts develop?

A

Older (embryological, foetal) fibres are never shed - compacted in the middle

No blood supply to lens, which depends entirely on diffusion for nutrition

Absorbs harmful UV rays preventing them from damaging retina but in the process, get damaged themselves

Damaged lens fibres - opaque - CATARACT

21
Q

WHat is the treatment of cataract?

A

Surgery – small day case – lens capsule opened – cataracteous lens removed by emulsification – plastic lens placed in capsular bag

22
Q

Where does aqueous humor drain?

A

angle of the anterior chamber through the trabecular meshwork into schlemms canal

23
Q

What is the 2nd global cause of blindness?

A

glaucoma

24
Q

WHat is the most commonly seen form of glaucoma?

A

Most commonly seen form of primary glaucoma is Primary Open Angle Glaucoma (POAG)

25
Q

What is glaucoma?

A

Raised intraocular pressure (IOP)

26
Q

How does glaucoma present and how is it picked up?

A

Bilateral

Patient can be asymptomatic for a long period of time

Picked up on routine eye exams

27
Q

What are the consequences of raised IOP?

A

Pressure on nerve fibres on surface of retina - die out - visual field defects

optic disc appears unhealthy, pale and cupped

This results in altered field of vision

Ultimately all nerve fibres are lost, which results in blindness

28
Q

What is the triad of signs for the diagnosis of glaucoma?

A
29
Q

What is the management of POAG?

A

Eye drops to decrease IOP

Prostaglandin analogues

Beta-blockers

Carbonic anhydrase inhibitors

Laser trabeculoplasty - used when eye drops are not working

Trabeculectomy surgery

30
Q

What is experienced in angle closure glaucoma?

A

Sudden onset, painful, vision lost/ blurred; headaches (often confused with migraine)

O/E – Red eye, cornea often opaque as raised IOP drives fluid into cornea

AC shallow, and angle is closed

Pupil mid-dilated

IOP severely raised

pictures:

Right eye: red and inflammed, cornea hazy, pupil mid-dilated

Slit-lamp photo showing shallow AC compared to normal AC

31
Q

Why does the angle close?

A

Functional block in a small eye – large lens

Mid-dilated pupil - periphery of iris crowds around angle and outflow is obstructed

Iris sticks to pupillary border (synechia) which prevents reaching AC. Leads to iris balooning anteriorly and obstructing angle

32
Q

What is the management of an acute eye episode?

A
  1. Decrease IOP

IV infusion with or without oral therapy – carbonic anhydrase inhibitors (acetazolamide)

Analgesics (reduce pain), antiemetics (reduce naeusa and vomiting)

Constrictor eye drops – pilocarpine

If no contraindication beta-blocker drops such as timolol

Steroid eye drops (dexamethasone)

2.Iridotomy (laser) - both eyes - to bypass blockage

33
Q

What is the difference between open angle and angle closure glaucoma?

A

open angle - gradual, painless build up of pressure

closed angle - suddent increase in IOP leading to red eye, severe pain and patient usually presents as an emergency

34
Q

What is Uveitis?

A

inflammation of uvea

35
Q

What are the different types of uveitis?

A

Anterior uveitis - iris with or without ciliary body inflammed

Intermediate uveitis - ciliary body inflammed

Posterior uveitis - choroid inflammed

36
Q

What are the causes of uveitis?

A

Isolated illness

Non-infectious autoimmune causes - eg: presence of HLA-B27 predisposes to anterior uveitis

Infectious causes - chronic diseases such as TB

Associated with systemic diseases - eg: ankylosing spondylosis

37
Q

What is the pathophysiology of anterior uveitis?

A

An inflammed anterior uvea (iris) leaks plasma and white blood cells into the aqueous humor

These are seen during slit lamp examination as a hazy anterior chamber and cells deposited at the back of the cornea

The eye is red, painful, with visual loss

Cells in the AC may settle inferiorly – “hypopyon

38
Q

What happens in intermediate uveitis?

A

In intermediate uveitis the ciliary body is inflammed and leaks cells and proteins.

This leads to a hazy vitreous

Patient complains of “floaters” or hazy vision

39
Q

What happens in posterior uveitis?

A

In posterior uveitis the choroid is inflammed

Since the choroid sits under the retina, the inflammation frequently spreads to the retina causing blurred vision

year 2 neuro - Robbie (48 decks)

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