Keratitis Flashcards
Name three types of non-infective keratitis
- CLPU
- Marginal keratitis
- Keratitis secondary to exposure
What is the pathogen that is responsible for protozoal keratitis?
Acanthamoeba
What are corneal signs of corneal disease (there are seven)?
-Punctate keratitis
- Superior limbic keratitis
- Corneal infiltrates
- Scaring (from trachoma)
- Corneal ulcer
- Vascularisation
- Hypopyon (accumulation of inflammatory material)
What are associated adnexal and conjunctival signs of corneal disease?
-Skin lesions (respects midline)
-Follicles (adenoviral)
-Conjunctival pseudo membrane (adenoviral)
-Conjunctival scaring (trachoma)
What are symptoms of corneal disease?
- Pain/discomfort (due to lots of pain receptors)
- Reduced VA
- Photophobia
What are two corneal diseases that are similar?
CLPU and MK
What causes the ulcer in CLPU and infilt?
Staphylococcus produces toxins and the ocular surface responds to these toxins.
What are some symptoms of CIE?
- Mild FB sensation
- Can be asymptomatic
- Mid pain
- Mild photophobia
- Mild epiphora
What does CIE stand or?
Contact lens infiltrative events this includes CLPU and CL-associated infiltrative keratitis- in these conditions bacteria does not cause progression to an infection (its an inflammatory response)
What are clinical signs of CIE?
- Mild conjunctival hyperamia
- Stromal infiltrate
- No AC activity
- Overlying epithelium may stain
What does flare represent ?
Breakdown of the blood aqueous barrier and there is protein in aqueous which leads to light scatter
Is microbial keratitis a sight threatening condition?
YES
Which contact lens wearers are at most risk of MK?
Extended contact lens wearers
Which is the most common bacteria to cause MK in contact lens wearers?
Gram negative psuedonomas
What are symptoms of MK?
Severe pain with a rapid onset, redness, photophobia, discharge, blurred vision, more pronounced photophobia
What are signs of MK?
- Loss of epithelium
- Stromal infiltrate + oedema (seen from a hazy cornea)
- Reduced VA
- AC activity (cells and flare)
- Fungal lesions deeper and feathery edges
BOWMANS MEMBRANE NOT INTACT
How is MK managed?
Emergency referral to an ophthalmologist, contact lenses should not be discarded as they are required for culture, they will be given intensive day and night therapy
Why is MK so serious?
It is sight threatening as they can penetrate the cornea which can lead to corneal scarring
What is the 123 that ophthalmologists use after a referral of suspected MK?
If there is the presence of AC inflammation (6-15 cells in a 1mm by 1mm SL beam),
2mm> in size or adjacent lesions or
3mm> from centre of cornea then a corneal scrape is formed to see what organisms is causing this immediately
What happens to patient who to no meet the 123 criteria from a suspect MK referral?
They are given antibiotic therapy straight away every hour
Is an corneal infiltration an infection?
No it is an inflammatory response to a toxin
What is another name for blepharitis?
Marginal keratitis
What are some signs and symptoms of marginal keratitis?
Lacrimination, red eye, photophobia, stromal infiltrate where the lid margin is in contact with the cornea, Hypereamia of adjacent conjunctiva,
What is a major RF of marginal keratitis?
Long standing conjunctivitis
