Opthalmic infections Flashcards
What is conjunctivitis? What are the broad categories?
Inflammation of the conjuntiva.
- Infectious (viral or bacterial)
- Non-infectious (allergic or non-allergic)
What are the viral agents that can cause conjunctivitis?
mainly adenoviruses, sometimes enteroviruses
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
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***
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
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
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
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
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.
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)
Define keratitis
Inflammation of the cornea
What is the pathophysiology of keratitis?
What are the risk factors fo keratitis?
Contact lenses****
Trauma to eye
eye surgery
topical corticosteroids
What are the clinical manifestations of keratitis?
- eye pain
- decreased vision
- photophobia
- foreign body sensation
- conjunctival injection
- tearing and discharge
- corneal infiltrate
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**
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
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)
