<prompt> In Herpes-Zoster keratitis, all of the following occurs except:Pseudodendritic keratitisAnterior stromal invasionSclerokeratitisEndotheelitis  <response>: Ans. c. Sclerokeratitis Ref: Kansk is 7ep 187-91; Yanoff 3ep. 222-24Herpes Zoster ophthalmicus commonly causes acute epithelial keratitis i.e. punctuate epithelial keratitis in 50 and pseudo dendritic keratitis 50, nummular anterior stromal keratitis 40 disciform deep stromal keratitis or endothelitis 34 and serpiginous ulceration 7. However, sclera-keratitis limbal vascular keratitis is least common !.Herpes Zooster Opthalmicus HZO It is caused by varicella zoster virus0 DNA virus After an infection with chicken pox in childhood or youth the virus lies dormant in Gasserian ganglion of trigeminal nerve to appear later, particularly in elderly people with depressed cellular immunity e.g. cancer, leukaemia, AIDS, lymphoma and immunosuppressed organ transplant recipients etc.Herpes Zooster Opthatmicus HZOClinical features Hutchinson sign: In herpes zoster opthalmicus. Involvement of the tip of nose supplied by external nasal nerve a terminal branch of nasociliary nerve, signifies increase risk of ocular involvement uveitis. Lesions are strictly limited to the one side of midline. Bilateral lesions can occur in the immunocompromisedClinical PresentationGeneral featuresCutaneous lesionsOcular lesionsNeurological complications Onset of illness is sudden with fever, malaise Severe neuralgic pain along the course of the affected nerve Appear in the area of involved nerve after 3-4 days of onset of disease. Affected areas becomes red and edematous followed by vesicle formation. Can cause small permanent pitted scars. Active eruptive stage lasts for 3 weeks. Anaesthesia dolorosa: Anaesthesia of the affected skin with associated post herpetic neuralgia Conjunctivitis: One of the MC complication Episcleritis and scleritis Keratitis:- Punctate epithelial keratitis0fine or coarse- Microdendritic epithelial ulcers- Nummular keratitis0- Disciform keratitis- Neuroparalytic ulcerations- Exposure keratitis Iridocyclitis0 Secondary glucoma0 Anterior segment necrosis and pthisis bulbi Motor nerve palsies especially 3rd, 4th, 6th and 7th Optic neuritis EncephalitisTreatment: Oral acyclovir no later than 4 days after the onset of rash In scleritis, sclerosing keratitis or iritis, dexamethasone 0.1 along with antiviral is used topically Systemic steroids are used in progressive proptosis with total occulomotor nerve palsy and optic neuritis. Oxyphenbutazone NSAIDs are sometimes useful in severe scleritis not responding to steroids. 