3. Viral Keratitis
dr. Frenky DJ
Introduction
Viral keratitis is the commonest cause of keratitis in the developed world.
There are two major types of the virus:
ā¢ Type I (most common and primarily infects the face), causing "cold sore" or
"fever blister."
ā¢ Type II (sexually transmitted form of herpes).
Infective keratitis is suppurative infection of cornea which may be associated
with epithelial defects and or signs of inļ¬ammation.
Reactivation including: stress, sun exposure or other UV light exposureĀ (such as
tanning beds), fever, trauma to the body (such as injury or surgery), menstruation,
certain medications.
ā¢ Individual layers of the cornea
ā¢ All the layers of cornea.
5. Viral Keratitis
dr. Frenky DJ
1. Herpes Simplex Virus
ā¢ Is a member of family Herpes Viridae.
ā¢ HSV is a large and complex enveloped virus measuring 150-200 nm.
ā¢ Direct contact by salivary droplets or fomites from children and adults with
active disease and also of asymptomatic virus shedding carriers.
ā¢ Humans are only natural host.
ā¢ Two types; HSV-1 & HSV-2.
MODE OF INFECTION
Lips, nose and cornea: HSV-1 (above
abdomen)āØ
(Close contact with patient suļ¬ering from
herpes labialis)
Genitals: HSV-2 (below abdomen)āØ
(to eye of neonate through infected genitalia
of mother)
8. Viral Keratitis
dr. Frenky DJ
a. Congenital & Neonatal Ocular Herpes
ā¢ Can be: Intrauterine (4%) Peripartum (10%) Post
partum (86%).
ā¢ HSV keratitis in a neonate is invariably associated
with conjunctivitis.
ā¢ Features; Diļ¬use microdendritis, serpiginous
epithelial defects or a punctate keratitis.
ā¢ Diagnosis; with nonpurulent conjunctivitis or keratitis.
ā¢ Treatment;
ā“ Topical antivirals (1% Triļ¬uridine ophthalmic solution
or 3% acyclovir ophthalmic ointment) in addition to
ā“ Systemic Acyclovir (2 g/day IV every 8 hourly for 14
days).
9. Viral Keratitis
dr. Frenky DJ
ā¢ Usually occurs in childhood.
ā¢ Uncommon during ļ¬rst 6 months of life.
ā¢ Mostly infection is subclinical or cause mild
fever, malaise & URTI.
ā¢ Ocular manifestation include;
b. Primary Ocular Herpes
ā“ Acute follicular conjunctivitis
ā“ Keratoconjunctivitis (lymphadenopathy)
ā“ Periocular & eyelid skin lesions
ā¢Early involvement of cornea; Diļ¬use punctate
keratopathy.
ā¢These lesions are mild and self limiting.
11. Viral Keratitis
dr. Frenky DJ
BLEPHARITIS
ā¢ Can result from primary infection or recurrent.
ā¢ C/F; vesicular lesions involving focal area of
eyelid with surrounding erythema.
ā¢ Typical lesion progresses to ulceration crusting
heals without scar, unless secondarily infected.
CONJUNCTIVITIS
ā¢Follicular conjunctivitis, is self limiting
ā¢May progress to keratitis
c. Recurrent Ocular Infection
KERATITIS
12. Viral Keratitis
dr. Frenky DJ
Epithelial involvement
Stromal involvement
Endothelium involvement
V
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A
L
K
E
R
A
T
I
T
I
S
Infectious epithelial keratitis
Neurotrophic keratopathy
Immune Stromal Keratitis
Necrotizing Stromal Keratitis
Endothelitis
13. Viral Keratitis
dr. Frenky DJ
ā¢ Caused by reactivation of live virus.
ā¢ C/F; pain, photopbobia, thin watery discharge, decrease vision if lesion is
central.
ā¢ Earliest epithelial lesion is characterized by corneal epithelial vesicles.
1. DENDRITIC ULCER
ā¢ Most common presentation of HSV keratitis.
ā¢ Derivative of DENDRON the Greek word for Tree.
ā¢ Features: branching linear lesion with terminal buds and swollen opaque
epithelial cells arranged in coarse punctate or stellate pattern that contain live
virus.
ā¢ Other associated features; Reduced corneal sensation, Mild subepithelial haze,
Follicular conjunctivitis.
EPITHELIAL INVOLVEMENT
Infectious Epithelial Keratitis
14. Viral Keratitis
dr. Frenky DJ
ā¢ Following healing there may be persistent punctate epithelial erosion and irregular
epithelium which settle spontaneously.
Dendrites; ļ¬uorescein along the length of lesion
Swollen epithelial borders; rose Bengal (devitalized cells)
15. Viral Keratitis
dr. Frenky DJ
ā¢ An enlarged dendritic ulcer is no longer
linear and is referred as geographic ulcer
(amoeboid)
ā¢ Feature; swollen epithelial borders that
contain live virus and scalloped borders.
2. GEOGRAPHIC ULCER
16. Viral Keratitis
dr. Frenky DJ
Treatment
Predominantly with nucleosidide analogue that disrupt viral DNA
1. TOPICAL
ā¢ Aciclovir 3%
ā¢ Ganciclovir 0.15%
ā¢ Triļ¬uridine
2. DEBRIDEMENT; for resistant cases
(protects adjacent healthy epithelium and eliminates antigenic stimulus to stromal
inļ¬ammation)
3. ORAL ANTIVIRAL THERAPY; Aciclovir 200-400mg
ā¢ CYCLOPLEGICS; Homatropine 1%
ā¢ Topical ANTIBIOTICS
ā¢ Skin lesion; Aciclovir cream
17. Viral Keratitis
dr. Frenky DJ
ā¢ Results from active viral diseases.
ā¢ It has proximity to limbus with
accompanying blood vessels.
ā¢ Features; epithelial lesion,
inļ¬ltrates with WBC from nearby
limbal vessels with adjacent limbal
injection, anterior stromal inļ¬ltrates
underlying the ulcer.
ā¢ More symptomatic due to intense
inļ¬ammation.
ā¢ Rare and most often confused with
staphylococcal marginal diseases
3. MARGINAL ULCER
18. Viral Keratitis
dr. Frenky DJ
ā¢ Arises from impaired corneal innervation combination with decrease tear
secretion.
ā¢ Failure of re-epithelization resulting from corneal anaesthesia.
ā¢ Features; irregularity of corneal surface. lack of normal corneal lustre.
ā¢ Defect is oval in shape with smooth borders, stroma beneath it is grey and
opaque, may become thin
ā¢ Ulcer has thickened border formed by heaped up epithelium.
ā¢ Complication; stromal scarring, NVZ, necrosis, perforation, secondary
bacterial infection.
Treatment;āØ
Stop all unnecessary topical medications.
- Artiļ¬cial tears.āØ
- Topical Antibiotics.āØ
- Gentle debridement.āØ
- Bandage contact lens.āØ
- Conjunctival ļ¬apping.āØ
- Tarsorrhaphy (Botulinum, Surgical)
Neurotrophic Keratopathy
EPITHELIAL INVOLVEMENT
19. Viral Keratitis
dr. Frenky DJ
ā¢ Occurs due to active viral replication within stroma, immune mediated
ā¢ Characterised by: āØ
- Epithelial defect.āØ
- Stromal necrosis & melting.āØ
- Dense stromal inļ¬ltrate.āØ
- Associated Ant. Uveitis with KPās underlying areas of active stromal
inļ¬ltration.
ā¢ Complications:āØ
- Corneal thinning & perforation.
- Scarring āØ
- VascularizationāØ
- Lipid deposition.
ā¢ Treatment
- Topical Antiviral
- Topical antibiotics & cycloplegics.āØ
- Conjunctival ļ¬apping & cyanoacrylate glue in cases of perforation.
STROMAL INVOLVEMENT
1. Necrotizing Stromal Keratitis
20. Viral Keratitis
dr. Frenky DJ
ā¢ Found in about 20% of patients with ocular HSV.
ā¢ Viral antigen in stroma triggers intra stromal inļ¬ammation.
ā¢ Overlying epithelium is usually intact.
ā¢ Characterised by: āØ
- Stromal inļ¬ltration (punctate) - Stromal edema.āØ
- Wessley immune ringāØ
- Stromal neovascularisation āØ
- Lipid keratopathy.
ā¢ Complications:āØ
- Disciform keratitis āØ
- Scarring
ā¢ Treatment;
- Topical steroids
- Topical AntiviralsāØ
- Topical Antibiotics, Lubricants & Cycloplegics. - Oral steroids in severe
cases.
2. Immune Stromal Keratitis
STROMAL INVOLVEMENT
21. Viral Keratitis
dr. Frenky DJ
ā¢ P a t h o g e n e s i s u n k n o w n , m a y b e
immunologic.
ā¢ Classiļ¬ed; 1. Disciform 2. Diļ¬use 3. Linear
ENDOTHELITIS
ā¢ C/F; blurred vision with haloes around
light discomfort redness
ā¢ Signs; central zone of stromal oedema,
often with overlying epithelial oedema,
granulomatous KP underlying oedema,
DM folds in severe cases, WESSELY
RING, Decreased corneal sensation.
1. Disciform Endothelitis
ENDOTHELIUM INVOLVEMENT
22. Viral Keratitis
dr. Frenky DJ
ā¢ Topical steroids with antiviral cover-prednisolone1% or dexamethasone
0.1%
ā¢ Monitor IOP
ā¢ Cycloplegics for comfort if needed
ā¢ With active epithelial lesion; steroid as low as possible, more frequent
antiviral regimen.
ā¢ Oral steroids- .
ā“ Severe stromal inļ¬ammation
ā“ Reduce steroid induced IOP elevation
ā“ Avoid viral promotion in infectious viral keratitis
ā¢ Topical ciclosporin 0.05%
ENDOTHELIUM INVOLVEMENT
23. Viral Keratitis
dr. Frenky DJ
ā¢ Scattered KP spread over the entire endothelium
ā¢ Stromal oedema involving entire cornea
ā¢ Microcystic epithelial oedema
ā¢ T/t-topical and systemic; steroids, antivirals
2. Diļ¬use Endothelitis
3. Linear Endothelitis
ā¢ Line of KP from limbus, may be sectoral or circumferential
ā¢ Edema present peripheral to line of KP, extending to limbus
ā¢ Microcystic epithelial oedema
ā¢ T/t-topical and systemic antivirals and corticosteroids
ā¢ Corneal decompensation is common
ENDOTHELIUM INVOLVEMENT
24. Viral Keratitis
dr. Frenky DJ
ā¢ Varicella zoster virus also referred as human herpes virus type 3.
ā¢ Causes; varicella (chickenpox) & herpes zoster (shingles).
ā¢ Herpes zoster derives its name from Greek word HERPEIN; to spread, to creep
Zoster; girdle or zone.
ā¢ Life time risk of herpes zoster is 10-30%.
2. Herpes Zoster
25. Viral Keratitis
dr. Frenky DJ
ā¢ Increasing risk (>70 years)āØ
ā¢ Neoplastic diseasesāØ
ā¢ Immunosuppressive drugs
ā¢ Organ transplant recepients
ā¢ HIV
ā¢ Others; syphilis, TB, malaria, emotional & physical stress.
Risk Factors
Pathogenesis
ā¢ Humans are only known natural host to VZV
ā¢ Structure; core of double stranded DNA surrounded by icosahedral
nucleocapsid with an outer cell membrane containing glycoproteins,
carbohydrates, lipids.
ā¢ This outer envelope helps in attachment and penetration of virus into human.
27. Viral Keratitis
dr. Frenky DJ
ā¢ Painful erythematous areas with a maculopapular rash which respects the
midline.
ā¢ Within 24 hours, groups of vesicles appear and these become conļ¬uent over
2ā4 days.
ā¢ Boggy oedema of the upper and lower lids is common and often spreads to
the contralateral side of the face.
ā¢ Vesicles pass through a pustular phase crust and dry after 2ā3 weeks.
ā¢ Large, deep haemorrhagic lesions in immunodeļ¬cient patients
ā¢ Lesions heal to leave residual skin destruction and depigmented scars
ā¢ Zoster sine herpete is shingles without a rash.
Skin Lesions
29. Viral Keratitis
dr. Frenky DJ
Oral antiviral;
ā¢ Aciclovir (800 mg 5 times/day)
ā¢ Newer agents; valaciclovir 1 g TID or famciclovir 250ā500 mg TID have more
convenient regimens, are better tolerated and are at least as eļ¬ective as
Aciclovir..
Intravenous Aciclovir; 5ā10 mg/kg TID in encephalitis, and
immunocompromised individuals
Systemic steroids; Prednisolone in tapering doses.
Treatment
30. Viral Keratitis
dr. Frenky DJ
ā¢ Causative agent for epidemic keratoconjunctivits
ā¢ Caused by serotype 8,19,37
ā¢ Highly contagious, via hands and fomites
ā¢ Corneal trauma facilitates infection
ā¢ Incubation period-8 days
ā¢ Symptoms-insidious onset Pain, photophobia, watering, Children may have
fever and lymphadenopathy.
ā¢ Associated with-Follicular keratoconjunctivitis, Palpebral oedema,
Preauricular lymphadenopathy (pathognomic), Haemorrhagic conjunctivitis.
3. Adenovirus
31. Viral Keratitis
dr. Frenky DJ
STAGE-1: corneal epithelial vesicle like elevation, 25-30 microns.āØ
STAGE-2: 2-5 days later, lesions coalesce and involve deeper epithelium,
classical epithelial punctate keratitis lesion.
STAGE-3: faint subepithelial inļ¬ltrates present beside the punctate keratitis.
STAGE-4: nummular opacities, may be present weeks to month after initial
episode. (residual scarring & visual impairment may occur)
32. Viral Keratitis
dr. Frenky DJ
ā¢ Treatment-āØ
Artiļ¬cial tears
Topical vasoconstrictors
Steroids
Cold compress