Ocular Infections Flashcards
3 common causes of bacterial conjunctivitis in neonates?
Staph aureas
N. gonorrhoea
Chlaymydia trachomatous
all babies under 2 need referred to opthalmology
3 common causes of bacterial conjunctivitis in adults / children ?
Staph aureas
Strep pneumoniae
H. influenza -esp kids
antibiotic that covers most bacterial conjunctivitis?
Chloramphenicol
alternative antibiotic for staph aureas in bacterial conjunctivitis?
fusidic acid
Tx of bacterial conjunctivitis caused by coliforms?
gentamicin
Tx of bacterial conjunctivitis caused pseudomonas aeruginosa?
gentamicin
Tx for chlamydial bacterial conjunctivitis?
oxytetracycline
potential S/Es of chloramphenicol
- common
- rare
- rare in babies
Allergy - red itchy eyes
Irreversible anaplastic anaemia
Grey baby syndrome (hypotension and cyanosis in young babies)
effect of chloramphenicol on staph …
bactericidal or bacteriostatic???
bacteriostatic for staph
bacterocidal for step + H. influenza
“follicular grains of rice” in a lower eyelid is probably a sign of … ?
chlamydial conjunctivitis
Often CHRONIC in young adults
They may not have any of the GU symptoms
3 common viral causes of conjunctivitis?
whats most common?
adenovirus - #1 common
herpes simplex
herpes zoster
how does adenovirus conjunctivitis present?
pink eye
watery
no discharge
what is keratitis?
infection of the cornea
potential causes of non-infective conjunctivitis?
#1 is allergy toxic autoimmune neoplastic reaction to contact lenses
how would you detect keratitis on examination?
look for white corneal lesion
how bad is bacterial keratitis?
it can be sight threatening
also normally only ever occurs alongside another pathology
management of bacterial keratitis
- admit
2. give eye drops every hour for 48 hours
Tx for keratitis caused by most things: Gm +/- ?? (2)
gentamicin
cefuroxime
what is the public health problem with Ofloxacin?
it is being over-used for corneal ulcers so developing resistance
what does ofloxacin cover?
Gm - organisms
not strep pneumoniae
used for bacterial keratitis
how does herpatic keratitis present?
green eyes!!
dendritic corneal ulcers!!
very painful!!
recurrent!!
Tx of herpetic keratitis?
(antiviral)
Aciclovir - esp if have dendritic corneal ulcers
what happens if you use steroids for herpatic keratitis?
corneal melt + perforation woo
most common cause of keratitis
viral — adenovirus
How does adenoviral keratitis present?
- Hx
- sign O/E
Hx of URTI
Subepithelial infiltraties
commonly bilateral cause so contagious
what fungal infection causes keratitis in people who wear contacts?
ACANTHOMOEBA
a - can - tho - moeba
2 causes of fungal keratitis?
acanthamoeba - contacts
pseudomonas aeruginosa - dodgy water sources + soil
dangerous complication of orbital cellulitis?
compartment syndrome
Orbital only - not preseptal
5 common causes of orbital cellulitis (all quite standard)
staph strep coliforms H. influenza anaerobes
common recent Hx of orbital cellulitis - where has infection come from?
Paranasal sinusitis
management of orbital cellulitis??
CT for an abscess
Assess if any damage to the nerves, or any muscle restriction
G.A and drainage
What is endophthalmitis?
infection of the whole eye
very painful + red
sudden onset - typically post-surgery
NORMALLY commensal - #1 is staph epidermidis
Tx of endophthalmitis?
Inreavitreal (into eye) antibiotics
- vancomycin
- cefrazidime
- amikacin
+ topical antibiotics
+/- systemic antibiotics
what is chorioretinitis?
Chorioretinitis is an inflammation of the choroid (thin pigmented vascular coat of the eye) and retina of the eye. It is a form of posterior uveitis
3 causes of chorioretinitis
- 1 rare in UK
rare = CMV (cytomegalovirus) in AIDS
Toxoplasma gondii
Toxocara canis
tell me about toxoplasma gondii
A CAUSE OF CHORIORETINITIS
- protozoan nematode
- cats and raw meat
- get mild flu symptoms
- normally no complications so no Tx
- if immunocompromised = get cysts
tell me about toxocara canis
A CAUSE OF CHORIORETINITIS
- parasitic nematode
- cats and dogs
- stays in worm form
- rare - forms granulomas causing irreversible vision loss
what kind of sample is taken if you suspect bacterial keratitis?
corneal scrape
what kind of sample do you take if you suspect endopthalmitis?
culture of aqueous / vitreous
what samples do you take for chorioretinitis? (different for each)
acanthamoeba = microscopy / contact lense culture
toxoplasma / toxocara = serology
what antibiotic “action” does chloramphenicol do?
inhibit. …
- protein synthesis?
- nucleic acid synthesis?
- cell wall synthesis?
protein synthesis !!
what is dacrocystitis?
lacrimal system gets blocked up + swollen due to infection.
2 bacterial causes of anterior uvieitis ?
2 viral causes?
TB + syphilis
herpes S + Z
pain
photophobia
hypopyon
keratic precipitates
what am I?
anterior uveitis
what is blepharitis?
infection of the eyelids
generally similar to conjunctivitis with grit + mild discharge
what causes anterior blepharitis? (2)
whats the difference in presentation?
staphylococcal - ulcers (styes) and trichiasis (ingrown eyelashes)
seborrheic - dandruff + chalaxia cysts. 50% have acne rosacea.
what eye condition is associated with acne rosacea?
sebhorreic blepharitis
what presents with a white corneal lesion?
bacterial keratitis
