Exam 2 - Ophthalmology III (Eye infections)

Learning Objectives:

• Identify the different types and subtypes of ocular infections

• Review infective pathogens associated with each type of infection

• Discuss treatment options available for each infection

Which anatomical parts of the eye provide ocular protection?

• Eyelids: physical barrier against foreign material

• Tears contain immunoactive substances

  • Lactoferrin, lysozyme, beta lysin, tear-specific albumin, and immunoglobulin A (IgA)

• The conjunctiva and corneal epithelial cells create a tight barrier that prevents any microbes from entering

• Conjunctiva: contains mast cells, conjunctiva-associated lymphoid tissue, and is vascularized

What is keratitis?

• Inflammation of the cornea

  • 4 different types: Bacterial, Viral, Fungal, Parasitic

• One of the leading causes of blindness in world

Which pathogens are most commonly found in bacterial keratitis?

• S. aureus, S. pneumoniae (opportunistic pathogens)

• P. aeruginosa

• Moraxella

What is the physical presentation of bacterial keratitis?

• Decreased vision, photophobia, pain, hyperemia

• Tearing, mucopurulent discharge

• Hypopyon

• Stromal infiltration

• Eyelids also affected

Which antibiotics are used for bacterial keratitis?

• Gram (+) cocci → Cefazolin, Vancomycin, Bacitracin, Fluoroquinolones

• Gram (-) cocci → Ceftriaxone, Ceftazidime, Fluoroquinolones

• Gram (-) rods → Tobramycin or gentamicin, Ceftazidime, Fluoroquinolones

• No organism id’ed or multiple types of orgs id’ed → Cefazolin + (Tobramycin or Gentamicin or Fluoroquinolones)

Which antibiotic class can you use for both gram (+) and gram (-)?

Fluoroquinolones

Which abx class is considered our 1st line agents?

Broad-spectrum fluoroquinolones considered 1st line treatment

• Ciprofloxacin 0.3%, ofloxacin 0.3%, norfloxacin 0.3%, moxifloxacin 0.5%, gatifloxacin 0.3%

• Every 2 hours

What is the coverage of aminoglycosides (tobramycin/gentamicin)?

• Good against gram (-) bacteria, staphylococci, some streptococci

• SE: stinging, burning, TOXIC to corneal epithelium

What is the coverage of cephalosporins?

• Good against non-penicillinase producing gram (+) organisms and some gram (-) bacilli like E. coli, Klebsiella, P. mirabilis

• SE: mostly well tolerated

What is the coverage of vancomycin?

• Effective against staphylococcal species

• SE: irritation

What can we use for improving discomfort (like eye spasms) in patients with bacterial keratitis?

• Cycloplegic drops: scopolamine 0.25% TID → Useful for improving patient discomfort

  • Ciliary body spasms

  • Prevent synechiae formation

• MOA: block acetylcholine at the parasympathetic sites

• SE: stinging, blurred vision

Why are cycloplegic agents useful for eye spasms?

Keratitis infection are painful → leading to spasms

• Cycloplegic agents “paralyze” the part of the eye muscles, preventing:

  • Ciliary body spasms

  • Preventing synechiae formation (when the iris starts to adhere to cornea or lens)

What is the treatment regimen if a patient with bacterial keratitis has their vision threatened (may lose their vision)?

Triple therapy

• Tobramycin or gentamicin q30-60 minutes alternating with Cefazolin or Vancomycin q1 hour

• Oral fluoroquinolones are also added on

Aminoglycoside + (Cefazolin or Vancomycin) + Fluoroquinolones

Can/should we use steroids in bacterial keratitis? Why or why not?

NO!

• Control damaging inflammatory responses but also facilitate replication of pathogens due to immunosuppression in local area

• Also can accelerate corneal thinning, thereby increasing the risk of corneal perforation

• May be given once infection is under control

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What are the different types of viral keratitis?

– Herpes-simplex (HSV)

– Varicella-zoster (VZV)

– Epstein-Barr (EBV)

– Cytomegalovirus (CMV)

What is the presentation of viral keratitis?

• Hyperemia, photophobia, pain, tearing, decreased vision

• Unilateral (not always, but can be)

• Crusting on eyelids

• Affects many areas of the eye

• Hallmark is dendritic lesion that occurs on corneal epithelium

  • Seen by fluorescein staining

Can/should we use steroids in HSV viral keratitis?

NO!

What is the treatment strategy for HSV keratitis treatment?

• Can affect multiple areas of the eyes

• If there is eyelid/skin involvement

  • Use Erythromycin or bacitracin ointment BID to skin lesions

  • Warm or cool soaks to skin lesions TID

• Debridement

• Topical antivirals

• Oral antivirals (acyclovir) in severe disease

• Surgery

What areas of the eye can viral keratitis affect?

1) Epithelium

2) Stroma

What is the treatment for corneal epithelial disease (viral keratitis in the epithelium)?

• Trifluridine 1%, 1 gtt 9x/day

  • Duration: 7-14 days

  • SEs: burning, stinging, blurred vision

• OR ganciclovir 0.15% gel 5x/day + (scopolamine 0.25% TID or homatropine 5% TID) + acyclovir 400mg PO 5x/day

Trifluridine (9x/day) OR Ganiciclovir + Scopalamine TID + Acyclovir (400mg 5x/day)

What is the treatment for corneal stromal disease (viral keratitis in the stroma)?

Corneal Stromal Disease

• Trifluridine 1%, 1 gtt TID-4x/day OR acyclovir 400mg po 5x/day + Scopolamine 0.25% TID

  • Trifluridine 3-4x/day is PROPHYLACTIC dose

• Steroids may used ONLY if localized in stroma

  • Prednisolone acetate 1% 1 gtt 4x/day

Trifluridine (3-4x/day) (or Acyclovir) + Scopalamine TID (for pain)

**only instance in which steroids MAY be used**

What is the dose of acyclovir used for corneal epithelium or stromal disease?

Acyclovir 400mg PO 5x/day

What is the only acceptable situation in which we can use steroids in viral keratitis?

Corneal STROMAL disease

• If the affected area isthe stroma, it is no longer considered an ACTIVE infection

  • But now, antigens have created a T-lymphocyte response, therefore we can use steroids

What is the presentation of viral keratitis due to varicella-zoster virus?

• Also known as Herpes-Zoster ophthalmicus

• Presentation:

  • Hallmark is appearance of rash only on one side of head and face

  • Upper eyelid is usually inflamed and edematous

  • Blurred vision, photophobia, hyperemia

  • Eyelids are crusted

  • Hutchinson sign

  • Conjunctiva is edematous and often has petechial hemorrhage

  • Epithelial keratitis with pseudodendritic lesions

    • More on periphery of cornea

    • No terminal bulbs

  • Corneal changes may take time to form → Within first week or even months

What is the treatment of viral keratitis due to varicella-zoster?

• Oral acyclovir 800mg 5x/day for 7-10 days ***note the difference in dosing

  • Or oral valacyclovir 1g TID or famciclovir 500mg TID for 7 days

• Bacitracin or erythromycin ointment BID (used topically on skin for any opportunistic pathogens)

• Cool compresses, cleansing

What is the presentation of fungal keratitis?

• Hyperemia, photophobia, tearing, discharge

• Hypopyon, satellite lesions surrounding primary infiltrate

• Severe anterior chamber reaction

• Frequent corneal abscesses

• May see a gray-white stromal infiltrate***

  • Infiltrate with feathery border

  • Appears similar to bacterial keratitis, bacterial ulcer

What are the common pathogens that cause fungal keratitis?

Fusarium, aspergillus, and candida

What can we use to treat fungal keratitis?

Antifungal

• Natamycin 5% drops q 1-2 hour around the clock, then tapered over 4-6 weeks

• OR amphotericin B 0.15% drops + flucytosine topical and oral

Add-ons

• Scopolamine 0.25% TID

• Can add oral antifungals

  • Voriconazole, fluconazole, ketoconazole

Takes months to cure

Can/should we use steroids in fungal keratitis?

NO!

What is acanthamoeba?

Common pathogen that causes parasitic keratitis

• Predominantly in soil and water environments such as ponds, swimming pools, hot tubs

• Often misdiagnosed as herpetic keratitis

  • Need confocal microscope and Giemsa stain to observe cysts and trophozoites

Precipitating factors:

• Contaminated water

• Contact lenses → 93% of cases have been associated with contact lens wear

• Corneal trauma

What is the presentation of acanthamoeba parasitic keratitis?

• Severe pain, hyperemia, photophobia

• Conjunctival injection (bloodshot eyes) and chemosis (swelling)

• Infiltrates can be observed around corneal nerves in the epithelium

• In the stroma, characteristic ring appears similar to herpes

• Corneal ulceration can develop

What do we use to treat acanthamoeba?

• PHMB 0.02% or chlorhexidine 0.02%, 0.04%, 0.06% every 1 hour

  • If treatment failure → oral itraconazole/ketoconazole or clotrimazole 1% gtts or linezolid 0.2% gtts

• Atropine 1% TID (cycloplegic)

• May add clotrimazole 1% drops, miconazole 1% drop, or paromomycin drops Q2H (antifungal drops)

• Duration: 3-6 months—years!!

• Corneal transplant may be necessary

What are counseling points for contact lens wearing patients?

• Stay away from water – Not sterile!!

• Follow directions of lens and lens case changing

  • Solution needs to be changed daily

  • Replace contact lens case every 3 months

• Do NOT sleep in lenses!!!

What is blepharitis?

• Chronic bilateral inflammatory condition of the lid margins

• May be due to a secondary infection

• Anterior: eyelid skin, eyelashes, assoc. glands

• Posterior: inflammation of the meibomian glands

• Common cause of recurrent conjunctivitis

What are complications of blepharitis?

Hordoleum & Chalazions

What is used for treatment of blepharitis?

• Eyelid scrub BID

• Warm compresses 4x/day

• Artificial tears

• Severe: Erythromycin or bacitracin ung qhs

• Lotilaner (Xdemvy®) 0.25% solution

  • Approved for Demodex blepharitis

  • 1 gtt OU BID x 6 weeks

What is a hordoleum?

A stye or localized, red, swollen, acutely tender area on upper and lower lid

• Common staphylococcal abscess

• Can be internal or external

How do we treat hordoleum?

• Warm compresses (1st line)

• Exision

• Bacitracin/erythromycin ung 4x/day acutely then BID for 1 week

What is chalazion?

• Common inflammation of the meibomian gland

• Hard, non-tender swelling of upper or lower lid

  • Redness and swelling

How do we treat chalazion?

• Warm compresses with massage

• Incision and curettage (if it doesn’t resolve on its own)

• Local steroid may also be effective

What are the two types of cellulitis?

1) Pre-septal

2) Orbital

Pre-septal Cellulitis:

• Location: Eyelid and surrounding skin anterior to orbital septum

• Presentation: pain, proptosis, lid swelling and redness

• Cause: Local facial/eyelid injury, insect/animal bite, conjunctivitis, chalazion

• Pathogens: S. aureus

Orbital cellulitis:

• Location: Soft tissue of orbit posterior to orbital septum

• Presentation:

  • Pain, proptosis, lid swelling and redness

  • Fever, malaise, restriction of extraocular movements, impaired vision

• Cause: Extension of a sinus infection (ethmoid)

• Pathogens: S. pneumoniae

How do we treat pre-septal cellulitis?

Oral abx: amoxicillin/clavulanic acid 500mg TID or 875mg BID

How do we treat orbital cellulitis?

IV ceftriaxone/cefotaxime/ampicillin-sulbactam/ pipericillin-tazobactam + vancomycin

• If PCN allergy: levofloxacin or metronidazole

Requires hospitalization

What are complications of cellulitis?

• Complications: loss of vision, meningitis, sinus thrombosis, cerebral abscess, death

• Need to treat ASAP!

• Usually requires hospitalization in severe cases

What is endophthalmitis?

Infection inside the globe of the eye, two types:

1) Exogenous – Most common form

• Penetration of eye from trauma, surgery, erosion of an external eye infection

2) Endogenous

• Occurs when infectious organisms invade from the bloodstream

What are symptoms of endophtalmitis? What pathogens are associated with it?

• Symptoms: Pain, hypopyon, progressive-deterioration of vision, photophobia

  • ~2-5 days after surgery

• Pathogens:

  • S. epidermidis and aureus, Streptococcus sp., P. aeruginosa, Bacillus sp

  • Rare fungal/viral

What are tx options for endophthlamitis?

• Intravitreal:

  • Vancomycin 1mg + (one of the following)

    • Ceftazidime 2mg, gentamicin 100 mcg or amikacin 200-400mcg

  • Fungal: amphotericin B 5mcg

• Vitrectomy (surgical procedure)

What is bacterial conjunctivitis?

• “Pink eye” → Inflammation of the conjunctiva

• Symptoms:

  • Foreign-body sensation, hyperemia, burning, moderate tearing, profuse exudate, chemosis (swelling), eyelid sticking

  • Pain

Bacterial conjunctivits is usually self-limiting, but which patients would receive treatment?

• Neonates

• Kids with suspected H. influenzae

• Rr anyone with hyperacute infection**

  • Hyperacute infection:

    • Rapidly progressive

    • Severe, sight-threatenting

    • N. gonorrhoeae, N. meningitides

What medications can be used for bacterial conjunctivitis?

• Trimethoprim /polymixin B

• Gentamicin, tobramycin

• Neomycin

• Fluoroquinolones (ciprofloxacin, ofloxacin, gatifloxacin)

• Erythromycin

• Sodium sulfacetamide

Mild infection: trimethoprim/polymixin B 4 gtt/day for 5-7 days

Moderate infection: FQs 1 gtt 6-8x/day tapered 4x/day for 7-10 day

What instance would require systemic treatment for bacterial conjunctivitis?

Gonococal infections

→ Must also check/treat for chlamydia

What is the most common cause of viral conjunctivitis?

• Adenovirus most common cause

  • Herpes simplex common in kids

  • VZV during chicken pox or zoster

What are symptoms of viral conjunctivitis?

• Symptoms: Profuse watery discharge, marked foreign body sensation (feels like something is in the eye but there isn’t), hyperemia, eyelid sticking

• Usually self-limiting, no treatment for it

• Bilateral (both eyes)

How would we treat viral conjunctivitis?

• Supportive treatments only

• Cold compresses, artificial tears

• Watch for rebound sensitivity, corneal involvement

  • Esp if using topical decongestants (topical decongestants not recommended)