Eye Infections Flashcards
Eye examination?
What it examines?
Inverted ophthalmoscope and slit lamp
- Visual acuity and intraocular pressure
> Starts with the lids and adnexae, and ending with the funduscopic
examination.
What is microbial conjuctivitis?
Inflammation of the thin lining of the inner eyelid and front of the eyeball
- dilation of the conjunctival blood vessels
Epidemiology of microboial conjunctivitis?
Affects males and females of all ages but mostly children
- Viral cases are more common in adults
> mostly adenovirus
Risk factors for microbial conjuctivitis?
- contact lens wear
- contaminated ocular medications
- exposure to an infected person
- vaginal versus cesarean delivery
- visits to camps
- swimming
Signs and symptoms of microbial conjuctivitis?
- Itching
- Light sensitivity
- Pink color
- Swelling
- Preauricular lymphadenopathy
- Secretions
- Discharge
Diagnosis of microbial conjunctivitis?
Laboratory diagnosis not needed
- Conjunctival scraping
Viral causes of conjunctivitis?
- adenovirus - The most common cause of viral conjunctivitis is infection
- herpes simplex virus (HSV)
- picornavirus
- EBV
- Mumps
- Influenza virus
- herpes zoster virus
Causes of bacterial conjunctivitis?
- Staphylococcus aureus,
- Streptococcus pneumoniae,
- Haemophilus species,
- Moraxella,
- Corynebacterium diphtheriae,
- Neisseria species, and enteric gram-negative rods
Gonococcal conjunctivitis?
- cause - Neisseria gonorrhoeae
- signs + symptoms - hyperpurulent discharge
- treatment - ceftriaxone is the drug of
choice
Chlamydial conjunctivitis?
- Cause - Chlamydia trachomatis
- signs + symptoms - Unilateral and have concurrent genital infection
- treatment - Oral antibiotics such as azithromycin or doxycycline are effective treatments
Cause of Trachoma?
Serotypes A, B and C of C. trachomatis
- Repeated infections causes the eyelashess turn inwards leading to scarring and blindness
> 1.9 million people blinded by trachoma
Epidemiology of trachoma?
- More than 42 countries endemic
- Preschool children at risk, get it from family members
Note: 15 countries declared by WHO to have eliminated trachoma
including Malawi as of 5th October 202
Stages of trachoma?
- Trachomatous inflammation follicular (TF)
- five or more follicles of larger than 0.5 mm on upper tarsal conjunctiva - Trachomatous inflammation intense (TI)
- inflammatory thickening obscuring more than half the normal deep tarsal vessels - Trachomatous conjunctival scarring (TS)
- presence of easily visible scars in the tarsal conjunctiva - Trachomatous trichiasis (TT)
- at least one eyelash rubbing on the eyeball or evidence of recent removal of in-turned eyelashes - Corneal opacity (CO)
- corneal opacity blurring part of pupil margin
What is the SAFE strategy?
- Erythromycin and tetracycline for 5 days repeatedly
- Single dose azithromycin
- Initiated in 1993
- Antibiotics supplied by manufacturer (Pfizer)
What is infectious keratitis?
infection of the cornea (microbial keratitis) is an ophthalmic emergency requiring immediate attention
- one of the most common causes of visual impairment in working age adults
Risk factors for infetious keratitis?
- contact lenses
- corneal abrasions
- physical and chemical trauma
- refractive surgery
- diabetes
- immunosuppressive diseases
- topical steroids
Other causes of infectious keratitis?
- Parasites
- African sleeping sickness
- leshmaniasis
- cryptosporidia - Fungal
- candida spp
- blastomyces spp
Causes of bacterial keratitis?
- S. aureus
- coagulase-negative staphylococci
- S. pneumoniae
- Pseudomonas aeruginosa^.
- Less commonly, fungi or acanthamoeba
Symptoms of bacterial keratitis?
- pain
- decreased vision
- tearing
- itching
- photophobia
Signs of bacterial keratitis?
- redness
- discharge
- epithelial ulcers corneal infiltrates
Diagnosis of bacterial keratitis?
- Slit lamp examination
- corneal scrapings
- Empiric abx
Treatment of bacterial keratitis?
Topical abx are mainstay of treatment
What is herpes simplex keratitis?
- The global incidence of herpes simplex keratitis was calculated at
approximately 1.5 million/year - primary or recurrent depending on whether it is the patient’s first
episode - ask about a history of cold sores or previous viral keratitis
Treatment for HSV keratitis?
- oral antivirals (aciclovir or valaciclovir)
- topical steroids
What is infectious endopthalmitis?
inflammation inside the eye that can be caused by infection with microbes, including bacteria or fungi
Risk factors for infetious endopthalmitis?
- Cataract surgery,
- intravitreal injections trauma,
- filtering bleb (for glaucoma),
- corneal infection,
- bacteraemia or fungemia
Most common causes of infectious endophhalmitis?
- coagulase negative staphylococci
- S. aureus
- streptococci
- Gram-negative bacilli
Clinical features of infectious endopthalmitis?
- pain
- redness
- Decreased vision
- Hypopyon
Treatment for infectious endopthalmitis?
- intravitreal antibiotics such as ceftazidime or vancomycin injected by an
ophthalmologist. - vitrectomy may be beneficial to avoid loss of vision
- Samples may be sent to the laboratory if acquired
- systemic abx may be given*
What is uveitis?
Inflammation of the iris, ciliary body and choroid
1. Anterior (iritis)
2. Intermediate (pars planitis)
3. Posterior (retinitis, choroiditis)
4. Pan uveitis usually TB or syphilis
- Anterior causes are usually viral (HSV)
- usually, no systemic features
Etiologies of uveitis?
- CMV
- Toxoplasmosis
- Lyme disease
- Brucellosis
- leprosy
Diagnosis of uveitis?
Clinical
Laboratory findings, culture of vitreous humour and even PCR
Serological tests can be used to rule out causes
Name Infections of the eyelid?
- hordeolum
- chalazion
- marginal blepharitis
Hordeolum?
acute infection of a sebaceous gland of the lid, usually caused by Staphylococcus aureus
Chalazion?
a sterile granulomatous reaction to inspissated sebum within an obstructed meibomian gland
Marginal blepharitis?
is a diffuse inflammation of the lid margins
