microbiology

Question 1

organisms causing bacterial conjunctivitis in
neonates
others
treatment?

Answer 1

neonates: s.aureus, n.gonorrhoea, chlamydia trachoma’s
others: s.aureus, h.influenzae, s.pneumoniae

swab (viral, bacterial, chlamydial) then give abx. - chloramphenicol

Question 2

when should chlamydial conjunctivitis be suspected

treatment

Answer 2

young adults
bilateral
rx: topical oxytetracycline
(oral azythromycin for genital infection)

Question 3

what often precedes adenoviral conjunctivitis

Answer 3

URTI

Question 4

dendritic ulcers

Answer 4

herpetic keratitis

Question 5

treatment of herpetic keratitis

Answer 5

acyclovir

NO STEROIDS - would cause corneal melt

Question 6

non sight threatening keratitis

Answer 6

adenoviral

Question 7

chloramphenicol 
what does it not treat 
when should it be avoided 
bactericidal / static for what?
what does it inhibit?

Answer 7

pseudomonas aeurginosa
avoid in aplastic anaemia, allergy
bactericidal for strep, haemophilus 
bacteriostatic for staph 
inhibits peptidyl transferase enzyme

Question 8

what type of abx have beta lactam ring

Answer 8

penicillins and cephalosporins

Question 9

what type of abx inhibit DNA gyrase

Answer 9

quinolones

Question 10

common contaminant of eye drop bottles

Answer 10

pseudomonas

Question 11

imaging for orbital cellulitis

Answer 11

CT

Question 12

what often causes orbital cellulitis

Answer 12

paranasal sinusitis

Question 13

painful, esp. on eye movement

Answer 13

orbital cellulitis

Question 14

what causes endopthalmitis

organisms?

Answer 14

operations
endogenous
usually due to conjunctival commensals - commonest is staph epidermidis

Question 15

eye is red in endoptalmitis - T or F ?

Answer 15

T

Question 16

treatment for endopthalmitis

Answer 16

INTRAVITREAL amikacin and vancomycin

topical abx

Question 17

protozoa that causes toxoplasmosis

what can you get it from?

Answer 17

toxoplasmosis gondi

from tick bites

Question 18

what causes toxocara

how does it affect the eyes

Answer 18

get it from cats and dogs 
parasitic nematode (ringworm)
can't replicate in humans but form granulomas which cause irreversible vision loss

Question 19

whats the one part of the eye with lymph drainage

Answer 19

conjunctiva

Question 20

What is anterior chamber associated immune deviation

Answer 20

placement of foreign antigen into ocular microenvironment causes systemic form of intolerance

Question 21

what is sympathetic ophthalmia

mediator?

Answer 21

trauma/surgery to one eye causes bilateral, granulomatous uveitis
primary mediator is T cells
injured eye is the ‘exciting eye’ - other is the ‘sympathising eye’

Question 22

what type of hypersensitivity is ocular cicatricial pemphigoid

Answer 22

type 2