Infections Of The Eyes

Question 1

Bacterial Conjunctivitis

Answer 1

Etiology

• S. Pneumo
• S. aureus
• M. Catarrhalis
• Proteus
• E. coli
• G/C (rare - neonatal presentations)

Clin Presentation

• UNILATERAL (auto-inoculation makes it bilateral)
• LOTS Purulent discharge/crusting (may be glued shut on awakening)
• No pruritis

Differential Diagnosis
-Gram stain

Tx

• Topical antibiotics during day (TMP/polymyxin B drops)
• Erythromycin ointment paste at night
• Systemic antibiotics if severe

Prevention

• transmission via fomites or contact
• good hygiene/avoidance

Question 2

Viral Conjunctivitis

Answer 2

Etiology

• adenovirus most common
• Consider herpes virus (HSV, EBV, HZV)

Clin presentation

• mostly BILATERAL
• watery discharge
• pruritis/irritation
• tender prearicular lymphadenopathy

Tx
-Symptoms (self limiting 10-21 dz course)
        artif tears
        topical antihistamines
-HSV or HZV refer to ophthalmologist 

Prevention

• HIGHLY CONTAGIOUS
• Fomites and washing hands (finger spreading)

Question 3

Gonococcal/Chlamydial Conjunctivitis

Answer 3

Etiology

• Neonates from mother’s birth canal
• Sexually active young adults

Clin Presentation

• Similar presentation to bacterial conjunctivitis
• Hx dysuria, discharge or G/C
• Photophobia/dysuria (Chlamydia)
• Severe conjunctivitis and keratitis with eventual permanent visual impairment

Differential Diagnosis
-Hx

Tx

• STAT OPTHO REFERRAL
• ceftriaxone + azithromycin
• Systemic antibiotics

Prevention
-Transmission via birth canal, sexual intercourse, non-chlorinated swimming pools, and direct/fomite contact

Question 4

Bacterial Keratitis (Definition)

Answer 4

Inflammation of the cornea

Question 5

Herpes Simplex Keratitis

Answer 5

Etiology
-Most common corneal infection in the US

Clin Presentation

• Dendritic abrasion appearance with fluorscein (also diagnostic)
• usually oral/labial infection (reactivates on trigeminal nerve)
• Hx of HSV

Tx

• Complicated
• Acyclovir
• Valacyclovir
• HSV prophylaxis if recurrent
• Steroids to control immune response (after dendritic lesions have healed)

Complications

• stromal inflammation
• bacterial superinfection
• scarring

Question 6

Herpes Zoster Ophthalmicus

Answer 6

Etiology
-HZV reactivation in ophthalmic division of trigeminal

Clin Presentation

• Starts as blepharoconjunctivitis
• Hutchinson’s sign on tip of nose STRONG indication of eye involvement
• Possible posherpetic neuralgia and nerve palsies

Differential Diagnosis
-Appears spread throughout on Fluorecin eye exam (because infection coming from within body)

Tx

• acyclovir or valacyclovir
• Refer to ophthalmology

Question 7

Orbital Cellulitis

Answer 7

Etiology
-more common in children (7-12 y/o)
-associated with sinusitis or other local infection
-involvement of tissues posterior to orbital septum
-bacterial
MRSA, strep, H. Influenza, anaerobes and pseudomonas
-fungal (diabetics)
Mucor, aspergillus

Clin Presentation

• Proptosis (eyeball pushed forward)
• Ophthalmoplegia (pain with eye movement)
• eyelid Edema/erythema
• possible conjunctivitis
• Headache, fever, malaise
• Vision loss can occur

Differential Diagnosis

• Preseptal cellulitis (anterior to orbital septum, no proptosis or ophthalmoplegia = usually trauma related)
• CBC for WBC count (will be high)
• CT

Tx

• MEDICAL EMERGENCY = IV antibiotics right away
• nafcillin + metronidazole/clindamycin
• vancomycin for MRSA infection
• close monitoring