## Herpes simplex keratitis

- dsDNA virus
    - HSV1: airborne
    - HSV2: sexually transmitted
    - Ascends the sensory nerve axon to reside in the trigeminal ganglion

- Ocular involvement: blepharoconjunctivitis, keratitis (epithelial, stromal, endothelial, neurotrophic), uveitis, retinitis, bacterial superinfection
    - Primary infection in childhood commonly manifests with blepharoconjunctivitis, malaise, periorbital vesicular rash and preauricular lymphadenopathy

### Epithelial keratitis
- FB sensation, pain, blurred vision, lacrimation
- Superficial punctate keratitis progresses to stellate erosion then to dendritic ulcer with terminal bulbs
- Ulcer base stains with fluorescein, margins and terminal bulbs stain with Rose Bengal
- Reduced corneal sensation
- Patchy iris atrophy

Tests
- Conjunctival and corneal swabs
- Scrapes: Giemsa stain shows multinuclear giant cells
    - Histopathology shows intranuclear inclusion bodies (Lipschutz bodies or Cowdy type A inclusions, also seen in VZV infection)

Management
- Topical antiviral
- Cycloplegia
- Oral antivirals in recurrent attacks

### Stromal keratitis
- Multiple diffuse opacities
- Corneal vascularisation (‘interstitial keratitis’)
- Lipid exudation
- Scarring
- Thinning
- Anterior chamber activity, possibly raised intraocular pressure

Management
- Topical steroids: defer until the epithelium is intact. Use minimum effective dose
- Systemic antivirals: associated with reduced risk of recurrence
- Cycloplegia
- Monitor/treat IOP
- Surgery: gluing, tectonic graft, DALK, or PK (less desirable)

### Disciform keratitis (endotheliitis)
- Possibly viral antigen hypersensitivity rather than reactivation
- Typically painless
- Blurred vision
- Haloes
- Central/paracentral disc of corneal oedema
- Descemet’s folds
- Mild AC activity may be chronic
    - Focal KPs: Wessley’s ring
    - Mutton fat KPs

- Raised IOP

Tests
- Consider AC tap for PCR if atypical presentation or no previous history of herpetic disease

 Management
- Topical steroids: defer until epithelium intact and use minimum effective dose
- Preservative free treatments
- Systemic antivirals: continued prophylactically
- Cycloplegia
- Monitor and treat IOP

### Other manifestations
- Geographic ulcer: in immunocompromised, or those given inappropriate steroids
- Metaherpetic ulcer: no live virus, but failure of epithelial healing
- Drug toxicity, neurotrophic cornea, low-grade inflammation

## Differences between HSV and VZV
- Zoster
    - Demographic:
        - Elderly
        - Immunosuppressed

    - Dermatome
        - Complete
 
    - More painful and more likely to develop post-herpetic neuralgia
    - Nummular stromal infiltrates (coin shaped)
    - Raised plaque-like lesions stain with Rose-Bengal
    - Mucous epithelial plaques
    - Sectoral iris atrophy
    - No terminal bulbs

- HSV
    - Incomplete dermatome
    - Patchy iris atrophy
    - Terminal bulbs

## Herpes Zoster Ophthalmicus (HZO)
- Tzanck smear: an easy test but not sensitive
    - Involves de-roofing vesicular lesions and spreading fluid on a slide followed by Giemsa staining to look for multinucleated giant cells

- Direct fluorescent antibody and PCR of corneal scrapes or vesicular fluid is highly sensitive and specific
- However the diagnosis is clinical and antivirals should be started for those where clinical suspicion is high

### HZO risk factors
- Immunosuppression: chronic illness, drugs, HIV
- Age (>60)
- Caucasian (4 times more likely than Afro-Caribbean)

### Neurotrophic ulcers
- Round ulcers with heaped-up elevated edges
- Typically inferonasal location due to Bell’s reflex
- Most common causes
    - HSV/VZV
    - Aneurysms
    - Stroke
    - Vn palsy
    - Diabetes
    - MS
    - Leprosy
    - Topical medication toxicity
    - Tumours: acoustic neuroma, angioma, neurofibroma

<HotTopic>

**The Herpetic Eye Disease Study**

Multiple arms

1. Effectiveness of topical steroids in stromal keratitis (on topical antivirals): safe and effective

2. Effectiveness of oral aciclovir in stromal keratitis: no benefit

3. Effectiveness of oral acyclovir in herpetic uveitis: effective

4. Effectiveness of oral acyclovir in recurrent HSV: decreased recurrence rate by 50%

5. Oral acyclovir does not prevent progression from epithelial to stromal disease

</HotTopic>

Herpes simplex keratitis dsDNA virus HSV1: airborne HSV2: sexually transmitted Ascends the sensory nerve axon to reside in the trigeminal ganglion Ocular…

Cornea

Herpetic Eye Disease

Intro

FRCOphth Part 2 Study Notes

Tumours, masses and neoplasia

Tumours overview

Uveitis

Uveitis background

Anterior uveitis

Intermediate uveitis

Uveitis in JIA

Uveitis with JIA

Retinal vasculitis

Sarcoidosis

Behcet's disease

Toxoplasmosis

Viral uveitis

Strabismus

Overview

Esotropia

Fungal uveitis

Mycobacterial uveitis

Adnexal masses

Spirochaetal uveitis (including Syphilis)

Exotropia

Melanoma

Nematode uveitis

Retinoblastoma

Retinoblastoma (for Part 2)

Incomitent

Voyt-Koyanagi-Harada syndrome

Conjunctival intraepithelial neoplasia

Vertical deviations

Sympathetic ophthalmia

Orbit and ocular adnexae

Orbit

AV Malformations and hamartomas

Arteriovenous malformations and hamartomas

Restriction syndromes

Paediatrics

Leucocoria

Congenital Cataract

Paediatric Glaucoma

Retinopathy of prematurity

Retinopathy of Prematurity

ROP-like disorders

Congenital nasolacrimal duct obstruction

White dot syndromes

Aniridia: Short Arm 11 Deletion (11p13)

Choristomas

Management Of Amblyopia

Alphabet patterns

Scleritis

Iris Nodules

Meningioma

Strabismus surgery

Optic nerve glioma

Lymphoma

Extraocular Muscles

Rhabdomyosarcoma

Idiopathic orbital inflammation

Orbital neuroblastoma

Anterior Persistent Foetal Vasculature

Lacrimal system

Metastatic lesions

Surgical Retina

Retinal Detachment

Vitreoretinal Interface And Macular Hole

Epiretinal Membrane

Medical Retina

Diabetic Eye Disease

Orbital Blood Vessels

Retinal Vascular Disease

Macular Degeneration

Central Serous Chorioretinopathy (CSCR)

Sickle Cell Retinopathy

Retinitis Pigmentosa

Albinism

Retinal Telangiectasias

Miscellaneous Retinopathies

Atropine And Myopia Progression

Pharmacology

Side Effects Of Systemic Drugs

Foetal Alcohol Syndrome

Neuro-ophthalmology

Optic Neuropathy

Papilloedema

Idiopathic Intracranial Hypertension

Chiasmal Disorders

Retrochiasmal Disorders

Migraine

Paranasal Sinuses

Supranuclear Motility Disorders

Third Nerve Palsies

Fourth Nerve Palsies

Sixth Nerve Palsies

Seventh Nerve Palsies

Anisocoria

Myasthenia Gravis

Myopathies

Blepharospasm

Functional Visual Loss

Lacrimal Glands

Phakomatoses

Developmental diseases

Tear Film

Eyelids

Blinking

Lid Malpositions

Anterior segment - ocular surface

Conjunctiva

Conjunctivitis

Sclera

Pigmented Conjunctival Lesions

Squamous Cell Carcinoma Of The Conjunctiva

Ocular Cicatricial Pemphigoid

Corneal Structure And Development