in this article we will discuss viral

keratitis and we will give a short brief

about herpes simplex and zoster

viruses

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H e r p e ss i m p l e x

Definition

Etiology

It is superficial , linear , branching ulcer due toinfection of the cornea by Herpes simplex virus

HSV is an epithelio-tropic virus , found in the trigeminalganglia in about 100% of population producing no symptoms .But when the body resistance decreases , it becomes activeinfecting the epithelium causing vesicles .

Precipitating factors

( which activates the virus )1- fever : common after pneumonia , influenza , common cold … etc.- Decreased immunity- Fever activates the virus .So, hot fomentation not used in treatment .2- Stress : as in operations , pregnancy , onset of menstruation .3- Immuno suppressant drugs : local of systemic .So, cortisone not used in treatment .4- U.V rays over exposure .

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Type 1

responsible for 75% of ocular infection . itusually affects the oropharyngeal region .

Types of HSV

H e r p e ss i m p l e x

Type 1 responsible for 25% of ocular infection .it usually affects the genital region .

The two types are differentiatedby specific antigens

1- primary herpes

2- recurrent infection

• Age : 6 months – 6 years . [ uncommon before 6 months dueto maternal antibodies ]• Clinical picture :- lid vesicles - follicular conjunctivitis- punctuate epithelial lesion ( no stromal lesion )

• Age : 15- 60 years .

The latent virus which is dormant in the Gasserian ( trigeminal )ganglion is re-activated and travel along the 5th nerve leading to :- lid vesicles - follicular conjunctivitis- dendretic ulcer - stromal immune keratitis- iritis

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clinical picture

sign

symptoms

Their is collection of symptomes accompanied togither thatpatiant complain from incloding:-pain:caused by exposure of nerve endings but not sever due tohypothesia -photophobia ,tearing,blepharospasm and redness-dimention of vision due to affection of epithelium espitially incentre.

first time HSV infection occurs from 6mounthes to 5 years onlyrepresented by mild fever and upper respiratory tract infection .

Epithelial lesions: -Dendretic ulcer;branching from ulcer end by bulbs(knobs)

-Geographical ulcer (Ameboid);flaring of ulcer when using steroidor immunosuppresed patiants.

-Marginal;on edge of cornea.

Rose bengal andlissamine green inhibit PCR detection of HSV DNA so scraping for PCR should be taken before staining.

Stromal lesion: -Non necrotizing (disciform) Keratitis;due to Ag-Abreaction. -Necrotizing Keratits;due to viral invasion.

H e r p e ss i m p l e x

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Treatment of dendritic ulcer

Most cases may resolve spontaneously in 3 weeksbut it is advised to give treatment to minimizestromal lesion caused by viral antigen.

• topical anti viral:

- Gancyclovir,

- Acyclovir.

- Trifluridine.

- Vidarabine.

- A cycloplegic agent may be added to avoid cilliary spasm.

- Topical treatment has the advantages of being less toxic and specificity also response usually occur in 2-5 dys and complete resolution I 2 weeks.

• oral therapy:

- Acyclovir may be used alone orally or with topical drugs It has the advantage of no ocular toxicity when used orally It is used rally in pediatric an immuocompromised persons It is used as long term prophylaxis in recurrent hsv ulcer.

- Vitamin A and C may be used also.

• depridement:

- the use of sharp instruments should be avoided to avoid cutting bowmans membrane and causing opacity it should be done by a cotton-tipped applicator and alchoholic solution of iodine.

• keratoplsty:

if other methods fail.

H e r p e ss i m p l e x

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organism

h e r p sz o s t e r

clinical picture

treatment

Varicella-zoster virus:Neurotropic virusAffect the eye if trigeminal ganglion isinfected with virus:In naso ciliary nerve affection ... cornealaffection In frontal nerve affection ... lid affection

sign

symptoms

Red eye Sever pain (neuralgic painPhotophobiaLacrimationBlepharospasmDecrease of visionVesicle

Cornea: Punctate keratitis Herpetic ulcer Deep keratitis Corneal anasthesia

their is another sign in lids and sclera a optic nerve : - HUTCHINSON’S SIGN: if tip of nose is affected with vesicle we can expect that ehe cornea will be affected (as tip of nose is supplied by a terminal branch of naso-ciliary nerve

Rest, Sedative and Analgesic for PainSkin lesion:Local: calamine lotion . Antibiotic PowderGeneral: Acyclovar tablet(zovirax) 1*4 for 7 days andAntibiotic(to prevent 2ry infection)corneal ulcer: Acyclovar mohamed mostafa

Differential diagnosis

Diffrantiate it from1- HSV2- red eye3- decrese of vision

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v i r a lk e r a t i t s

reverence

-Author: Jim C Wang (王崇安), MD Vitreo-Retinal and Cornea/Anterior Segment Subspecialist, Department of Ophthalmology, Kaiser Permanente Fontana Medical Center- Coauthor(s) David C Ritterband, MD, FACS Assistant Director of Cornea Service, New York Eye and Ear Infirmary; Clinical Professor of Ophthalmology, Icahn School of Medicine at Mount Sinai- Chief Editor Hampton Roy, Sr, MD Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences- date: Dec 07, 2015- web site: medscape.com

1-HSV

- Original article contributed by: Lisa M Nijm- All contributors: Alex Kozak, Brad H. Feldman, M.D., Lisa Nijm, MD, Mallika Doss, MD and Vatinee Bunya, MD- Assigned editor: Vatinee Bunya- Review: Assigned status Update Pending by Vatinee Bunya, MD on July 4, 2015.

- Original article contributed by: John B. Cason MD- All contributors: Brad H. Feldman, M.D. and John B. Cason MD

2-HSV

3-HZO

- Herpes Zoster Ophthalmicus(- Herpes Zoster Virus Ophthalmicus; Ophthalmic Herpes Zoster; Varicella-Zoster Virus Ophthalmicus)- By Melvin I. Roat, MD, FACS- website:http://www.merckmanuals.com/home/eye-disorders/corneal-disorders/herpes-zoster-ophthalmicus mohamed mostafa

the end of the article

thanks

VIRALKERATITS

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