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Viral Keratitis

CORNEAL DENDRITE

What else do you want to know

about this patient?

What would be your initial treatment?

Wilhelmus KR. Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis. Cochrane Database Syst Rev. 2010 Dec8;(12) 2

RISK FACTORS:REFRACTORY AND RECURRENT

3Mucci JJ, Utz VM, Galor A, Feuer W, Jeng BH. Recurrence rates of herpes simplex virus keratitis in contact lens and non-contact lens wearers. Eye Contact Lens. 2009 Jul;35(4):185-7.

Why use others?

valacyclovir (Valtrex)

famciclovir (Famvir)

Why not topicial trifluridine?

ORAL ANTIVIRALS

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Nguyen DQ, Srinivasan S, Hiscott P, Kaye SB. Thimerosal-induced limbal stem cell failure: report of a case and review of the literature.Eye Contact Lens. 2007 Jul;33(4):196-8.

Loutsch JM, Sainz B Jr, Marquart ME, Zheng X, Kesavan P, Higaki S, Hill JM, Tal-Singer R. Effect of famciclovir on herpes simplex virus type 1 corneal disease and establishment of latency in rabbits. Antimicrob Agents Chemother. 2001 Jul;45(7):2044-53.

Why do most ophthalmologists still use acyclovir as their oral agent of choice?

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Drug Treatment Prevention

Acyclovir 400mg 5 x day 400mg bid

Valacylovir 1000mg tid 500-1000mg daily

Famciclovir 250-500mg tid 250mg bid / 500mg daily

Cost of Oral Antivirals

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WHOLESALE COST Per Pill 1 month

Generic valacyclovir 500 mg tab $0.8475 $25.43 (500mg)

Generic famciclovir 500 mg tab $1.6906 $50.72

Generic acyclovir 400 mg tab $1.2700 $76.20 (800mg)

MARGINAL KERATITIS?

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IV or oral suspension

Long term prophylaxis:dose reviewed at least every 6 months (weight based!)

Dose:

Over 40kg 400mg bid

30mg/kg/day divided q8h

CHILDREN

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HZV HSV FACE OFF

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HSV HZV

Dendrite Ulcerated, terminal bulb Elevated, taper

Corneal sensation Variable Loss

IOP Rare elevation Trabeculitis

Live virus Yes YES

Antiviral Yes: viroptic 5-9xdayAcyclovir 400mg x 5Yes: topical andFamvir 500 tid

Less / More More often multiple lesions, endotheliitisMore often epi defects, iris defects, diffuse haze

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STROMAL KERATITIS?

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The Answered Questions The Unanswered Questions Clinical Practice

Stromal keratitis improves with steroids (HEDS 1 SKN)

Would longer steroid duration / taper lead to less treatment failures?Would oral antiviral prophylaxis benefit?

Longer taper, oral antiviral coverage is used commonly, trend toward leaving long-term

Stromal keratitis patients on steroids and trifluridine dont need acyclovir(HEDS 1 SKS)

What if the patient is not on trifluridine?

Oral antiviral is commonly substituted for topical antiviral

Acyclovir may help when added to steroid / topical antiviral treatment(HEDS 1 IRT)

Does it help? With trabeculitis, iritis, stromal keratitis, oral antiviral is commonly used

Addition of acyclovir to trifluridine in epithelial disease does not reduce the incidence of stromal keratitis (HEDS II)

Could acyclovir be used as an alternative to trifluridine?

Patients with first episode usually dont receive oral acyclovir

Acyclovir 400mg bid prevents recurrent herpetic eye disease

Lower dose? Treatment duration?

6 to 12 months duration, other oral antivirals substituted

HOW DID WE GET HERE?

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NEUROTROPHIC ULCER V. PERSISTENT EPITHELIAL DEFECT

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AAO guidelines:

5 minute soak:

70% ehtyl ethanol

1:10 sodium hypochlorite (bleach)

Gloves / Isolation room / Avoid waiting room

Avoid contact with surfaces / instruments / drops

DISINFECTION AND HYGIENE

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Povidone-Iodine 0.5% QID + Dexamethasone 0.1% QID x 10 days

Povidone-Iodine 5% wash?

Gancilovir gel (special access)?

The RPS Adeno Detector (Rapid Pathogen Screening)

Mixed results in studies

ACUTE TREATMENT

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WHEN TO TREAT

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VISION

PAIN

SEVERE

9 patients (12 eyes) with 13month follow-up

Steroid failures or responders

Cyclosporine 1% BID

Conclusion: IOP normalized and reduced medications

All patients stable (1/3) or improved (2/3)

Severity of symptoms improved

Trend of improved vision (2 lines)

TORONTO WESTERN HOSPITAL

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TAKE HOME POINTS

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Be aggressive with epithelial defects in neurotrophiccorneas: punctal cautery, tarsorraphy, serum tears

Dont debride routine or high risk HSV dendrites

Have your hospital stock viral cultures

Oral and topical antiviral for HZV pseudo-dendrites

Prevent and perhaps treat adenoviral conjunctivitis

Zostavax: the vaccine for your cataract patients!

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One million new episodes world-wide per year (epithelial keratitis), 5000 per year in Canada 0.014%

Besides HSV-1, much less common causes of dendritic epithelial keratitis:

HSV-2

Varicella-zoster virus

Co-infection with HSV-1 and human herpes virus 6

Very rarely, cytomegalovirus, epstein-barr virus, or adenovirus

Pseudodendrite: esp day 1 abrasion, exposure keratopathy, neurotrophic cornea (esp diabetic)

QUICK FACTS

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