Brainscape's Knowledge GenomeTM

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


See full index

Y3 - Opthalmology > Infective keratitis > Flashcards

Infective keratitis Flashcards

1
Q

What is keratitis?

A

Inflammation of the cornea

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

What is the most common cause of keratitis?

A

infection (particularly viral and bacterial)

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

What is the corneal epithelium?

A

the corneal epithelium forms the primary barrier to microbes and the tear film on the corneal surface

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

What three groups of bacteria most commonly cause infective keratitis when the corneal epithelium is disrupted?

A
  1. Staphylococcus
  2. Streptococcus
  3. Pseudomonas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are 3 bacteria that can penetrate intact corneal epithelium and can therefore cause keratitis without corneal obstruction?

A
  1. Neisseria gonorrhoea
  2. Neisseria meningitides
  3. Corynebacterium diphtheria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are 4 risk factors for bacterial keratitis?

A
  1. Contact lenses
  2. Corneal trauma
  3. eyelid disease
  4. Immunosuppression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

True or false: infective keratitis typically presents unilaterally

A

True

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

Give 5 general clinical presentations associated with infective keratitis:

A
  1. Ocular pain
  2. Photophobia
  3. Reduced visual acuity
  4. Diffuse conjunctival injection
  5. Eyelid oedema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give 3 additional clinical presentations associated with bacterial keratitis?

A
  1. Purulent discharge
  2. area of yellow/white infiltrate with clearly defined margins
  3. hypopyon in the anterior chamber
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is hypopyon?

A

Hypopyon is a medical condition involving inflammatory cells in the anterior chamber of the eye

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

Give 3 important questions to ask when conducting a contact lens history:

A
  1. Duration of wear
  2. Type of contact lens (short/long wear)
  3. Have they ever slept, showered or swam with their lenses in?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give 2 examinations used to investigate bacterial keratitis:

A

1) Snellen chart for visual acuity
2) anterior segment examination using slit lamp or fundoscope

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

What investigation may be used to gain insight into the causative organism in keratitis?

A

Corneal scrape/ conjunctival swab

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

What investigation should be carried out on contact lens wearers if infective keratitis is suspected?

A

send contact lenses and case off for culture

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

What guidance should be given to contact lens wearers if infective keratitis is suspected?

A

contact lens use should be discontinued IMMEDIATLY

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

What two topical antibiotic therapies are given for bacterial keratitis?

A
  1. Fluoroquinolone
  2. Cefuroxime with gentamicin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are 5 complications of bacterial keratitis?

A
  1. Spread of infection
  2. Corneal perforation
  3. Residual dense corneal scarring
  4. Irregular astigmatism
  5. Formation of cataracts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the two most common viral causes of keratitis?

A

1) herpes simplex
2) varicella zoster

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

What type of herpes virus causes viral keratitis?

A

Herpes simplex virus-2 (HSV-2)

20
Q

In which structure does HSV establish latency following primary infection?

A

trigeminal ganglion

21
Q

Describe the aetiology of herpes simplex epithelial keratitis:

A

following primary infection, HSV establishes latency in the trigeminal ganglion which can reactivate and move to the corneal epithelium

22
Q

How can you tell viral and bacterial keratitis apart from examination?

A

viral keratitis causes epiphora while bacteria keratitis causes purulent discharge

23
Q

What is epiphora?

A

Excessive tearing from one or both the eyes without any specific reason.

24
Q

What is the key diagnostic sign of HSV keratitis?

A

dendritic ulcers

25
Q

What are dendritic ulcers?

A

small green patches seen on fluorescein staining with linear branching morphology associated with HSV keratitis

26
Q

What is the main treatment for viral keratitis?

A

topical antivirals (aciclovir ointment) and epithelial debridement

27
Q

What is the name given to the varicella zoster infection of the ophthalmic branch of the trigeminal nerve?

A

herpes zoster ophthalmicus

28
Q

What are 3 clinical presentations specifically associated with herpes zoster opthalmicus?

A
  1. Rash in the V1 dermatomal distribution
  2. Punctate keratitis
  3. Psuedodendrites
29
Q

What is punctate keratitis?

A

small dots caused by cell death when the eye is viewed under high magnification

30
Q

What are pseudodendrites?

A

similar to dendritic ulcers but lack the terminal bulb seen in HSV

31
Q

Name 3 typical symptoms of herpes simplex epithelial keratitis?

A
  1. Discomfort, grittiness, red eye, reduced visual acuity and photophobia
  2. Epiphora
  3. A previous history of cold sores
32
Q

Name 4 typical clinical findings on examination for herpes simplex epithelial keratitis?

A
  1. Lids and lashes - mild erythema and oedema
  2. Conjunctiva - diffuse or cicumlimbal injection
  3. Cornea - dendritic ulcer
  4. Reduced corneal sensation
33
Q

What is the most common complication of herpes zoster ophthalmicus?

A

post-herpetic neuralgia

34
Q

What is post-herpetic neuralgia?

A

A complication of shingles, painful, blistering skin rash, which is caused by reactivation of herpes zoster virus.

35
Q

What are 4 risk factors for fungal keratitis?

A
  1. Corneal trauma
  2. Contact lens wear
  3. Immunosuppression
  4. Ocular surface disease
36
Q

True or false: the visual prognosis of fungal keratitis is generally good

A

false (it is an aggressive infection)

37
Q

What would the cornea look like under examination with fugal keratitis?

A

grey-white stromal infiltrate with fluffy margins. Satellite lesions may be seen. Rapid progression may occur with necrosis and corneal thinning

38
Q

What treatment is used for fungal keratitis?

A

topical antifungals (hour installation) and analgesia

39
Q

What protozoa commonly causes keratitis?

A

acanthamoeba

40
Q

Where are acanthamoeba found?

A

Fresh water and soil

41
Q

Give 3 clinical presentations specific to acanthamoeba keratitis:

A
  1. Ring shaped infiltrate with radial perineural infiltrates
  2. Epiphora
  3. Severe pain that is often disproportionate to mild clinical findings
42
Q

What type of investigation can be used to view acanthamoeba cysts in suspected acanthamoeba keratitis?

A

confocal microscopy

43
Q

What antiamoebic agent is commonly used to treat acanthamoeba keratitis?

A

topical PHMB (polyhexamethylene biguanide)

44
Q

What surgery can be used to treat very severe cases of infective keratitis?

A

penetrating keratoplasty (full thickness corneal transplant)

45
Q

True or false: acanthamoeba keratitis has a poor prognosis relative to other forms of infective keratitis

A

True

Y3 - Opthalmology (14 decks)

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