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Flashcards in Opthalmic infections Deck (34):
1

What is conjunctivitis? What are the broad categories?

Inflammation of the conjuntiva.

  • Infectious (viral or bacterial)
  • Non-infectious (allergic or non-allergic)

2

What are the viral agents that can cause conjunctivitis?

mainly adenoviruses, sometimes enteroviruses

3

What are the clinical manifestations of viral conjunctivitis?

Pharyngeal conjunctival fever:

  • Pharyngitis
  • Fever
  • Conjunctivitis
  • +/- preauricular LAD

Isolated conjunctivitis

Epidemic keratoconjunctivitis

  • conjunctivitis with keratitis
  • stronger foreign body sensation
  • may have subconjunctival hemorrhages

 

 

4

What are the manifestations of conjunctivitis? How to tell allergic vs. viral vs. bacterial?

  • conjunctival hyperemia (engorgement of blood vessels)
  • discharge, morning crusting of eye 
  • diffuse redness
  • burning or itching
  • conjunctival edema

Bacterial: unilateral, purulent discharge predominate complaint

Viral: watery discharge, burning or gritty feeling primary complaint, usually 2nd eye involved in 1-2 days

Allergic: bilateral, watery discharge, history. 

***normal visual acuity***

5

What is the treatment for viral conjunctivitis?

Supportive care, usually resolves in days to weeks.

Cold compresses, eye lubricant drops, eye decongestant drops.

Possibly exclude from work/school because it is highly contagious

6

What are the bacterial agents that can cause conjunctivitis?

Acute:

  • S. aureus
  • S. pneumoniae
  • S. pyogenes
  • H. influenzae
  • M. cattarhalis

Hyperacute:

  • N. gonorrhoeae

Chronic

  • Chlamydia trachomatis

7

What is the pathogenesis of allergic conjunctivitis? What are possible etiologies of non-allergic conjunctivits?

Allergic:

  • allergen in air causes IgE mediated immune response

Non-Allergic

  • post foreign body irritation
  • chemical
  • dryness

8

What is the clinical presentation of hyperacute conjunctivitis? How is it contracted?

Conjunctivitis with profuse purulent discharge (e.g. streaming down the face)

N. gonorrhea is passed genitals-->hands--> eyes

9

How does chlamydial conjunctivits differ from acute bacterial conjunctivitis? Types of conjunctivits 

There is a follicular response (the inside of the eyelid is bumpy), and the is not usually a lot of purulent discharge.

Trachoma: self-limited follicular conjunctivitis, usually seen in children.

Adult inclusion conjunctivitis: caused by sertain strains of C. trachomatis, that is chronic and unilateral. Doesn't respond to antibiotics.

 

10

What is the treatment for acute and hyperacute bacterial conjunctivitis?

Acute:

  • antibiotic eyedrops (e.g. azithromycin)

Hyperacute:

  • systemic therapy to cover gonorrhea (ceftriaxone) and chlamydia (doxycycline)

11

Define keratitis

Inflammation of the cornea

 

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12

What is the pathophysiology of keratitis?

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13

What are the risk factors fo keratitis?

Contact lenses****

Trauma to eye

eye surgery

topical corticosteroids

14

What are the clinical manifestations of keratitis?

  • eye pain
  • decreased vision
  • photophobia
  • foreign body sensation
  • conjunctival injection
  • tearing and discharge
  • corneal infiltrate

15

What are the infectious causes of keratitis? Can they be distinguished by presentation?

Bacterial:

  • S. aureus **
  • S. pneumoniae
  • S. pyogenes
  • Pseudomonas

Viral

  • HSV-1**
  • Adenovirus
  • VZV

Fungi

  • Fusarium

Parasitic

  • Acnthamoeba

**Can sometimes distinguish based on the pattern of corneal infiltrate**

16

What is the diagnostic approach to keratitis?

  • Referral to an opthamologist
  • Slit-lamp examination
  • Corneal scrapings (bacterial culture, viral culture +PCR, fungal cultura, wet mounts, culture for Acanthamoaeba, Giemsa stain)
  • Fluorescein dye

17

What is the treatment for bacterial keratitis?

Non-contact lens wearers

  • fluoroquinolone drops

Contact lens wearer

  • have to cover for pseudomonas --> aminoglycoside + pipercillin

18

What is the treatment for HSV viral keratitis?

What is the treatment for fungal keratitis?

What is the treatment for parasitic keratitis?

Viral:

  • acyclovir drops

Fungal

 

  • natamycin or amphotericin

Parasitic

  • propamidine + chlorohexidine

19

What is endophthalmitis? What are the 2 main types?

Infection of the aqueous +/- vitreous humour

  • exogenous (organism introduced from outside the body--> trauma, surgery, extension of keratitis)
  • endogenous (organism seeded from within the body

 

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20

What are the clinical manifestions of endophthalmitis?

Decreasing vision

eye ache

hypopyon

conjunctiva may be injected or edematous

21

What is the diagnostic approach to endopthalmitis?

  • S/S, physical exam
  • aspiration of vitreous humour --> bacterial and fungal cultures

22

What are the causative agents of endopthalmitis?

Bacteria

  • CNS
  • S. aureus
  • Steptococci
  • G(-) organisms

Fungal

  • candida

23

What is the treatment for endopthalmitis?

  • Medical emergency
  • Intravitreal antibiotics (vancomycin + ceftazidime) for all
  • Vitrectomy in severe cases or if trauma related (removal of vitreous humor)
  • Systemic antibiotics if trauma realted, or endogenous

24

Define orbital and periorbital (preseptal) cellulitis

Periorbital (preseptal) cellulitis: inflammation of the anterior portion of teh eyelid

Orbital cellulitis: inflammation of the orbit (fat, ocular muscles)

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25

What population are periorbital and orbital cellulitis most common in? Which is more comon?

Most common in children and periorbital is more common than orbital.

26

What some etiologies of periorbital cellulitis? Causative agents?

Local trauma:

  • insect bite, animal bite, foreign body, surgery

Infectious

  • URTI
  • tear duct infection (dacrocystitis)
  • sinusitis

S. aureus, S. pneumoniae, anaerobes, H. influenzae

27

What are the clinical manifestations of periorbital cellulits and what are the pertinent negatives?

  • Ocular pain
  • eyelid swelling
  • redness
  • no double vision
  • no increase in pain with eye movement
  • no eye bulging (proptosis)

28

What is the diagnostic approach to periorbital cellulitis?

  • S/S, history (e.g. insect bite)
  • Physical (no pain on eye movement)
  • If in doubt, perform CT of head

29

Treatment for periorbital cellulitis?

  • No topical antibiotics
  • Clindmycin OR Septra +Amoxil/clav

30

What are some etiologies of orbital cellulitis? Causative agents?

  • Rhinosinusitis ***
  • surgery
  • trauma
  • infection of teeth, middle ear, face

S. aureus, Streptococci, Anaerobes, H. influenzae

31

What are the clinical manisfestations of orbital cellulitis?

  • ocular pain
  • erythema
  • eyelid swelling 

AND

  • pain with eye movement
  • proptosis (bulging of eye)
  • double vision

32

What are complications of orbital cellulitis?

brain abscess

loss of vision

33

What is the diagnostic approach to orbital cellulitis?

  • S/S, history (rhinosinusitis)
  • physical exam (pain on eye movement)
  • if unsure, do CT of orbit and sinuses

34

What is the treatment for orbital cellulitis?