Microbiology & the eye

Question 1

What is inflammation of the entire globe called?

Answer 1

Endophthalmitis

Question 2

What are the common causes of bacterial conjunctivitis in neonates?

Answer 2

Staph. aureus
Neisseria gonohhoeae
Chylamydia trachometis

Question 3

What are the most common causative organisms in bacterial conjunctivitis in not neonates?

Answer 3

Staph. aureua
Strep. pneumoniae
Haem. influenzae (esp. children)

Question 4

Treatment of bacterial conjunctivitis

Answer 4

Usually self limiting but if needed cholramphenicol

Question 5

When should chloramphenicol be avoid?

Answer 5

History of aplastic anaemia or allergy

Question 6

How is viral conjunctivitis different from bacterial clinically?

Answer 6

Watery rather than mucousy discharge

Question 7

How does a viral conjunctivitis usually present?

Answer 7

Usually starts with URTI

Watery discharge

Question 8

Causes of viral conjunctivities

Answer 8

Adenovirus
Herpes Simplex
Herpes zoster

Question 9

What is Hutchin-Robinsons sign?

Answer 9

Sports on end of nose - Herpes zoster infection of trigeminal nerve (virus sits in ganglion then comes out at times of stress)

Question 10

When should chlamydial conjunctivitis be suspected?

Answer 10

Bilateral conjunctivitis in young adults

Question 11

What other symptoms may accompany chlamydial conjunctivitis?

Answer 11

Urethritis

Vaginitis

Question 12

What is bacterial keratitis usually associated with?

Answer 12

Other corneal pathology or conact lens wear

Question 13

Management of bacterial keratitis

Answer 13

Need admission for hourly drop

Question 14

What is a hypopyon?

Answer 14

White blood cells & inflammatory material in anterior chamber

Question 15

Typical presentation of bacterial keratitis with hypopyon?

Answer 15

Painful
Reduced vision
White mark in red eye (URGENT!!)

Question 16

What 2 virus most commonly cause keratitis?

Answer 16

Herpes simplex

Adenoviral

Question 17

Presentation of herpetic keratitis

Answer 17

Very painful
Can be recurrnt
Recurrences eventually result in reduced corneal sensation

Question 18

Why should herpetic keratitis not be treated with steroids?

Answer 18

Can cause corneal melt and perforation of the cornea

Question 19

Presentation of adenoviral keratitis?

Answer 19

Bilateral
Following URTI
Contagious
May affect vision

Question 20

Management of adeoviral keratitis

Answer 20

May be given topical AB to prevent secondary bacteria infection

Question 21

What keratitis is associated with washing lenses in ta water?

Answer 21

Acanthamoeba

Question 22

Typical features of pseudomonas aeruginosa keratitis

Answer 22

Farmers/gardeners
In eyes that have other problems
Takes a long time to heal

Question 23

Presentation of orbital cellulitis

Answer 23

Painful (especiialy on eye movements)
Proptosis
Often associated with paranasal sinusitis
Pyrexial

Question 24

First line investigation in suspected orbital cellulitis

Answer 24

CT scan

Question 25

What is dacrocystitis?

Answer 25

Infection of the lacrimal sac

Question 26

Organisms that cause orbital cellulitis

Answer 26

``` Staphylococci Streptococci Coliforms Haem. influenzae Anaerobes ```

Question 27

What is endophthalmitis?

Answer 27

Devastating infection inside the eye usually due to blunt trauma

Question 28

Presentation of endophthalmitis

Answer 28

Painful ++++ Decreasing vision Very red eye

Question 29

Organisms that cause endophthalmitis

Answer 29

Often conjunctival "commensals" | Most common is staph epidermis

Question 30

Treatment of endopthalmitis

Answer 30

Intravitreal amillacin and vancomysin and topical antibiotics

Question 31

What virus causes chlororetinitis in AIDs patients?

Answer 31

CMV

Question 32

What rotozoan infection causes chlororetinitis?

Answer 32

Toxoplasma gondil

Question 33

Treatment of toxoplasma gondil

Answer 33

Self limiting but would want to treat if close to disc

Question 34

What parasitic infection can cause chlororetinitis?

Answer 34

Toxocara canis (worm)

Question 35

Are toxocara canis able to replicate in humans?

Answer 35

No

Question 36

Why could toxocara be sight threatening?

Answer 36

Can form granulomas

Question 37

How is enophthalmitis diagnosed?

Answer 37

Aqueous/vitreous cultue

Question 38

How is acanthamoeba diagnosed?

Answer 38

Microscopy/culture

Question 39

How is bacterial keratitis diagnosed?

Answer 39

Corneal scrape

Question 40

What are the 3 types of swab?

Answer 40

Bacterial Chlamydial Viral

Question 41

What is the mechanism of action of chloramphenicol?

Answer 41

Inhibits peptidyl transferase enzyme (sops bacterial protein being made)

Question 42

Side effects of cholramphenicol

Answer 42

Allergy Irreversible aplastic anaemia Grey baby syndrome

Question 43

When is the site of action of penicillins?

Answer 43

Bacterial cell wall

Question 44

What is a common contaminant of eye drop bottles?

Answer 44

Pseudomonas

Question 45

What problems can be caused by pseudomonas contaminant?

Answer 45

Corneal ulcer

Question 46

Which bacteria is not treated by cholramphenicol?

Answer 46

Pseudomonas aeruginosa

Question 47

Which bacteria does fusidic acid treat?

Answer 47

Staph aureus

Question 48

What could treat bacterial onjunctivitis caused by pseudomonas aeruginosa??

Answer 48

Gentamicin

Question 49

What is the management for chylamidial conjuntivtiis?

Answer 49

Topical oxytetracycline

Question 50

First line treatment for bacterial keratitis

Answer 50

Ofloxacin

Question 51

What bacteria does ofloxacin not treat?

Answer 51

Strep. pneumoniae