keratitis Flashcards
what is keratitis?
-inflammation of the cornea
what are some different types of keratitis?
- bacterial keratitis
- herpetic keratitis
- adenoviral keratitis
- fingal keratitis
what are the most common organisms to cause bacterial keratitis?
- staphylococcus (gram +ve)
- pseudomonas (gram -ve)
- streptococcus (gram +ve)
contact lens related tend to be gram -ve
how does bacterial keratitis present?
-hypopyon (pool of WBC) in the eye
how does bacterial keratitis present?
-hypopyon (pool of WBC) in the eye
what are the investigations for bacterial keratitis?
-corneal scrapes
what is the treatment for bacterial keratitis?
need admission for hourly drops:
-alpha 4 quinolone (ofloxacin)
For strep pneumonia:
-gentamycin +cefuroxime
what is the most common cause of keratitis?
herpes simplex infection
what is the most common cause of keratitis?
-herpes simplex infection
what part of the cornea does herpes simplex usually affect in keratitis?
-epithelial layer of the cornea
how does herpetic keratitis present?
- DENDRITIC CORNEAL ULCER
- painful red eye
- photophobia
- vesicles around the eye
- foreign body sensation
- watering eye
- reduced visual acuity (this can vary from subtle to significant)
what investigations are done for herpetic keratitis?
- Flourescein staining to show dendritic corneal ulcer (dendritic describes the appearance of branching and spreading ulcer)
- slit lamp examination is required to find and diagnose keratitis
- corneal swabs or scrapings can be used to isolate the virus using a viral culture or PCR
what is the treatment for herpetic keratitis?
-Antivirals such as acyclovir
Put anaesthetic in eyes as it is painful!!
NO steroids as these cause corneal melt and perforation
why would you not use steroids in the eye to treat herpetic keratitis?
-as these cause corneal melt and perforation
what causes adenoviral keratitis?
-adenovirus
how does adenoviral keratitis present?
subepithelial infiltrates
- bilateral
- usually following URTI
- contagious
what is the treatment for adenoviral keratitis?
Antivirals- acyclovir
- Can give topical AB to prevent secondary infection
- Can require steroid to speed up recovery if becomes chronic
who is fungal keratitis common in?
-patients who wear contact lenses especially if they wash them in water
what organisms cause fungal keratitis?
0acanthamoeba
-pseudomonas aeruginosa
how does fungal keratitis present compared to other types of keratitis?
-it is less painful than others
what is the treatment for fungal keratitis?
Fungal:
anti-fungal (natamycin or voriconazole drops)
-pain relief
Acanthamoeba:
- anti septics (chlorohexidine every 30 mins for 6 weeks)
- antifungal (itraconazole or voriconazole drops)
TAKES A LONG TIME TO HEAL
