Microbiology in opthalmology Flashcards
Bacterial conjunctivitis
- presentation (3)
- causative organisms (neonates (3) and other ages (3))
- management (4)
- avoid ^^ in what?
-red eye and sticky discharge (mucus and pus)
hazy vision
-neonates: staph aureus/ neissieria gonorrhoeae/chlamydia trachomatis
Other ages: staph aureus/ strep pneumomiae/haemophilus influenzae
-swab and culture
topical antibiotic: chloramphenicol qds,
fusidic acid (stap aureus)
Gentamicin for pseudomonas aeuriginosa
-avoid if hx of aplastic anaemia
adenoviral conjunctivitis
- presentation (2)
- causative organisms (3)
- look for what sign?
-red eye without sticky discharge- watery discharge & itchiness
might be after URTI
-adenovirus
herpes simplex- white vesicles around eye
herpes zoster- manifests as URTI then lies latent in the trigeminal nerve till reactivated
-Hutchinson’s sign (vesicles on the end of the nose)
Chlamydial conjunctivitis
- presentation (3)
- examination (3)
- treatment
-chronic hx, unresponsive
bilateral conjunctivitis in young adults, no discharge
may have assoc vaginitis/urethritis
-under eyelid: “wet rice grain follicles”
coallece and scar downwards and affect vision and irritate the ocular surface
-topical oxytetracycline (oral azithromycin if genital)
Bacterial Keratitis + hypopyon
- what is it
- presentation (2)
- treatment (4)
- precipitations
- corneal ulcer full of inflammatory material, appears white
- reduced vision and white fluid in the eye due to pus in the ant chamber
-anaesthetise cornea and scrape off ulcer material: culture and admit for hourly drops
ofloxacin (gram neg coliforms)
Gentamicin + cefuroxime
-cornea damaged or contacts
Herpetic keratitis
- presentation
- management
-dendritic ulcer
very painful
might be recurrent and reduce corneal sensation
-NO STEROIDS= corneal melt and perforation
Adenoviral Keratitis
- presentation (3)
- treatment (2)
-bilateral inflammatory deposits on the cornea following URTI
may effect vision
-topical AB to prevent secondary infection
may need steroids if chronic
Keratitis with contact lenses
- causative organisms
- pathogenesis
-Acanthamoeba
pseudomonas aeruginosa
-cornea gets O2 from the indersurafec of the lid when the eye is closed and with lenses the cornea gets ischeamic and swells & more susceptible to infection
Fungal keratitis
-presentation
-opaque cornea developing over a few days
hx trauma form vegetation
Orbital cellulitis
- what is it (2)
- presentation (5)
- causative organisms (5)
- investigations
- treatment (2)
-compartment syndrome as the pus comes through the back of the orbit
direct spread of infection from sinuses or extension from focal orbital infection
-painfull on movement of eye proptosis pyrexial assoc with paranasal sinuses can be sight threatening
-staphylococci streptococci Coliforms heamophilus influenzae anearobes
-CT if muscle restriction/ optic nerve dysfunction
-Flucloxicillin and monitor
may need to drain abscess if present
Endophthalmitis
- what is it
- presentation
- treatment
-infection within the eye, generally post surgical
-very sore eye, decreasing vision
very red eye
-inject AB into vitrous gel as blood retinal barrier keeps systemic ones out :
intra-vitreal amikacin & vancomycin
Chorioretinitis
- assoc with
- presentation
- causative organism
- AIDS
- haemorrhagic retinitis, go blind quickly
- cytomegalovirus
Toxoplasmosis
- causative organism
- presentation in what group (3)
-toxoplasmosis gondii
-immunocompromised
can enter the latent phase with cysts forming
on reactivation can cause scarring in the eye and may be sight threatening
Toxocara Canis
-forms what in the eye
worm from cats and dogs
can form granulomas in the eye and irreversible visual loss
What is the major antibiotic used in opthalmology?
- action
- SE
Chloramphenicol
-inhibits the peptidyl transferase enzyme
bacteriocidal (strep & haemophilus) bacteriostatic (staph)
-allergy
irreversible aplastic anaemia
grey baby syndrome
