1 - microbiology Flashcards
what is bacterial conjunctivitis? treatment?
it’s very common infection of conjunctiva (covers sclera) - presents super red, angry, pus
= resolves by itself with basic drops - can use topical chloramphenicol
what is viral conjunctivitis?
it’s very common infection of conjunctiva (covers sclera) - it’s less severe than bacterial with just red eye with watery discharge
what bugs can cause viral conjunctiva?
- herpes simplex (also get extra yellow pustules)
- shingles
- adenovirus
what bugs cause bacterial conjunctivitis?
- staph aureus
- haemophilus influenza in kids
what is chlamydia conjunctivitis? treatment?
= not super common but do see - usually bilateral conjunctivitis in young adults (usually notice when unresponsive to treatment) - can get scarring under eyelid
treat - topical oxytetracycline
what is keratitis?
inflammation of cornea (bit that covers iris & pupil)
what is bacterial keratitis with hypopyon?
it’s inflammation of cornea from bacterial infection
hypopyon = white yellow liquid at bottom of eye (also has white infiltrates in middle of cornea)
what is treatment of bacterial keratitis with hypopyon?
admit to hospital for hourly drops of antibiotics (can’t give oral since cornea has no vascular supply)
what are the types of viral keratitis? presents?
- herpetic keratitis
- herpes zoster keratitis
- adenoviral keratitis
= they get dendritic ulcers and can be painful, gritty, light sensitivity & blurry vision.
- adenoviral keratitis gets snowflake changes
when is it important to NOT give steroid drops?
herpes keratitis = give aciclovir, NO STEROIDS (makes worse if give steroids)
what is acanthamoeba?
= not common but important to be aware since sever infection of cornea
(organism in warm tanks & soil etc - makes white ring of infiltration in cornea)
what is preseptal vs orbital cellulitis?
preseptal = upper eyelid inflammation
orbital = whole orbit inflammation (above & below eye inflamed)
what can cause orbital cellulitis?
inflammation of paranasal sinusitis - also dental sores
what scan should be done if orbital cellulitis?
CT to identify orbital abscesses
what is endophthalmitis? presents?
= very severe infection of inside eye (aqueous & vitreous humour)
- get super angry red eye with lots conjunctival swelling
- very painful, decreased vision, sight threatening
*just know that complication after cataract surgery!
what is management of endophthalmitis?
urgent referral to eye clinic, inject antibiotic directly to eye w amikacin & vancomycin
what are causes of chorioretinitis? what is seen on fundoscopy for each infection?
- AIDS (pale retina w striking haemorrhage)
- herpes simplex & varicella zoster (retinal necrosis & haemorrhages)
- candida (white infiltrates)
- toxoplasmosis (scarring - can get inflammation of scar)
- toxocara canis (granulomas with irreversible vision loss)
what bug from cats?
toxocara canis
what bug from undercooked meats & contaminated soil?
toxoplasmosis
what is steps for diagnosis of eye infections?
- swab for culture
- corneal scrape if bacterial keratitis
- aqueous culture if endophthalmitis
- microscopy if acanthamoeba
- serology for toxoplasma or toxocara
what is mode of action of chloramphenicol?
inhibits peptidyl transferase enzyme
what is the difference in discharge of bacterial vs viral conjunctivitis?
bacterial = pus
viral = watery
what is treatment of viral conjunctivitis?
if adenovirus = lubrication & cold compress
if herpes simplex & zoster = antivirals e.g. ganciclovir
what is anterior & posterior blepharitis?
anterior = infection at base eyelashes (form bacterial or seborrheic dermatitis)
posterior = inflammation of meibomian glands (run along posterior eyelid margin)
what is presentation of blepharitis?
- burning/itching/crusting eyelids
- symptoms worse in morning
- both eyes
- recurrent hordeolum (styes)
- contact lens intolerance
what is management of blepharitis?
- 1st self care hygiene & warm compress & treating assoc condition
if persistent anterior then topical chloramphenicol
if persistent posterior then oral doxycycline
what are complications of blepharitis?
- stye (hordeum)
- chalazion (meibomian gland cyst)
what is management of stye?
it’s self limiting resolving in 5-7 days, can also use warm compress to encourage draining of stye
