Microbiology of the eye Flashcards
Which organisms can cause bacterial conjunctivitis in the neonate?
Staph. aureus
Neisseria gonorrhoeae
Chlamydia trachomatis
Which organism can cause bacterial conjunctivitis particularly in children?
Haemophilus influenzae
Which organisms cause bacterial conjunctivitis (all ages but neonate)?
Staph aureus
Strep pneumoniae
How is bacterial conjunctivitis treated?
Swab
Topical chloramphenicol drops 4x daily
When should use of topical chloramphenicol be avoided?
History of aplastic anaemia
Chloramphenicol allergy
What is the diagnosis here?
Bacterial conjunctivitis
What organism is a common contaminant of eye drop bottles?
Pseudomonas aeruginosa
Which organisms cause bacterial conjunctivitis in contact lens wearers?
Acanthamoeba
Pseudomonas aeruginosa
What are the causative organsims of viral conjunctivitis?
Adenovirus
Herpes simplex
Herpes zoster
What is the diagnosis here?
Viral conjunctivitis caused by herpes simplex
What is the diagnosis here?
Herpes zoster opthalmicus
When should chlamydial conjunctivits be suspected?
Young adult/teen
Chronic history
Unresponsive to treatment
Bilateral
Symtpoms of urethritis or vaginitis
What is keratitis?
Inflammation of the cornea
What is a hypopyon?
Pus in the anterior chamber of the eye
Which patients is development of bacterial keratitis associated with?
Patients with existing corneal pathology
Contact lens wearers
Which viruses can cause keratitis?
Herpes
Adenovirus
What is the risk of treating herpetic keratitis with steroids?
Can cause corneal melt and perforation of the cornea
What is the diagnosis here?
Dendritic ulcer caused by herpetic keratitis
What is the lesion here and what is the diagnosis?
Hypopyon in bacterial keratits
What is the usual causative organism in bilateral keratitis?
Adenovirus
What illness does adenoviral keratitis usually follow?
URTI
What is the treatment for adenoviral keratitis?
Topical antibiotics
Steriods if becomes chronic
Which eye infection are subepithelial infiltrates associated with?
Adenoviral keratitis
What can cause fungal keratitis?
Trauma from vegetation
A patient presents to you with this painful eye, worsening on eye movement. You notice proptosis. He has a fever. What is the diagnosis?
Orbital cellulitis
How is orbital cellulitis treated?
Referred to ENT & opthalmology
CT scan for abscesses
Drain any abscesses
Broad spectrum antibiotics
What are the causative organisms in orbital cellulitis?
Staphylococci
Streptococci
Coliforms
Haemophilus influenzae
anaerobes
What is endopthalmitis?
A devastating infection of the inside of the eye
What is the most common causative organism of enopthalmitis?
Staph. epidermidis
How can a patient get endopthalmitis?
Post-surgical
Trauma
Endogenous
What is the treatment for endopthalmitis?
Intravitreal amikacin and vancomycin and topical antibiotics
What is chorioretinitis?
Inflammation of the choroid and retina
What is a protozoan cause of chorioretinitis?
Toxoplasmosis gondii
What are some of the symtpoms of infection with toxoplasmosis gondii?
Flu-like symtpoms
Causes cyst formation in immunocompromised
Which parasite can cause chorioretinitis?
Toxocara canis, a parasitic nemotode (roundworm)
How can toxocara cause visual loss?
Although parasite cannot replicate in humans and remains in larvae form it can form granulomas
What is the treatment for chlamydial conjunctivitis?
Topical oxytetracycline
How is bacterial keratitis diagnosed?
Corneal scrape
What is the treatment for bacterial keratitis?
4-quinolone (ofloxacin) except pseudomonas aeruginosa
Gentamicin and cefuroxime
What is the treatment for bacterial conjunctivitis?
Chloramphenicol except pseudomonas aureginosa
Then - gentamicin
