CORNEAL DENDRITE. What else do you want to know about this patient? What would be your initial treatment?

Transcription

1 Viral Keratitis

2 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 Dec8;(12) 2

3 RISK FACTORS: REFRACTORY AND RECURRENT Mucci 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 Jul;35(4):

4 ORAL ANTIVIRALS Why do most ophthalmologists still use acyclovir as their oral agent of choice? Why use others? valacyclovir (Valtrex) famciclovir (Famvir) Why not topicial trifluridine? 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 Jul;33(4): 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 Jul;45(7):

5 Drug Treatment Prevention Acyclovir 400mg 5 x day 400mg bid Valacylovir 1000mg tid mg daily Famciclovir mg tid 250mg bid / 500mg daily 5

6 Cost of Oral Antivirals WHOLESALE COST Per Pill 1 month Generic valacyclovir 500 mg tab $ $25.43 (500mg) Generic famciclovir 500 mg tab $ $50.72 Generic acyclovir 400 mg tab $ $76.20 (800mg) 6

7 MARGINAL KERATITIS? 7

8 CHILDREN 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 8

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10 HZV HSV FACE OFF HSV HZV Dendrite Ulcerated, terminal bulb Elevated, taper Corneal sensation Variable Loss IOP Rare elevation Trabeculitis Live virus Yes YES Antiviral Less / More Yes: viroptic 5-9xday Acyclovir 400mg x 5 More often multiple lesions, endotheliitis Yes: topical and Famvir 500 tid More often epi defects, iris defects, diffuse haze 10

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12 STROMAL KERATITIS? 12

13 The Answered Questions The Unanswered Questions Clinical Practice Stromal keratitis improves with steroids (HEDS 1 SKN) Stromal keratitis patients on steroids and trifluridine don t need acyclovir (HEDS 1 SKS) Acyclovir may help when added to steroid / topical antiviral treatment (HEDS 1 IRT) Addition of acyclovir to trifluridine in epithelial disease does not reduce the incidence of stromal keratitis (HEDS II) Acyclovir 400mg bid prevents recurrent herpetic eye disease Would longer steroid duration / taper lead to less treatment failures? Would oral antiviral prophylaxis benefit? What if the patient is not on trifluridine? Does it help? Could acyclovir be used as an alternative to trifluridine? Lower dose? Treatment duration? Longer taper, oral antiviral coverage is used commonly, trend toward leaving longterm Oral antiviral is commonly substituted for topical antiviral With trabeculitis, iritis, stromal keratitis, oral antiviral is commonly used Patients with first episode usually don t receive oral acyclovir 6 to 12 months duration, other oral antivirals substituted 13

14 HOW DID WE GET HERE? 14

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16 NEUROTROPHIC ULCER V. PERSISTENT EPITHELIAL DEFECT 16

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19 DISINFECTION AND HYGIENE 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 19

20 ACUTE TREATMENT 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 20

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22 WHEN TO TREAT VISION PAIN SEVERE 22

23 TORONTO WESTERN HOSPITAL 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) 23

24 TAKE HOME POINTS Don t debride routine or high risk HSV dendrites Have your hospital stock viral cultures Oral and topical antiviral for HZV pseudo-dendrites Zostavax: the vaccine for your cataract patients! Be aggressive with epithelial defects in neurotrophic corneas: punctal cautery, tarsorraphy, serum tears Prevent and perhaps treat adenoviral conjunctivitis 24

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26 QUICK FACTS 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) 26