Download MBBS Ophthalmology PPT 7 Ocular Tuberculosis Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Ophthalmology PPT 7 Ocular Tuberculosis Lecture Notes


Ocular Tuberculosis

Department of Ophthalmology

Acknowledgement

Some clinical photographs in this presentation are courtesy
Dr.Brad Bowling (Kanski's Clinical Ophthalmology, 8thEd.)

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Learning Objectives

? At the end of the class, students shall be able to

? Understand the pathophysiology of ocular tuberculosis.

? Recognize common manifestations of ocular tuberculosis.

? Understand the principles of managing the disease.

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INTRODUCTION

? Tuberculosis is a systemic disease of protean manifestations.
? It is a chronic infection caused by mycobacterium tuberculosis that is

characterized by formation of necrotizing granuloma

? Tuberculosis primary involves lung

? Secondary ocular TB is a common presenting form

? Incidence of Ocular TB ranges from 1.4 - 5.74%.

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? Ocular tuberculosis is an extra pulmonary form.
? Primary infection of the eyes is rare.
? Secondary ocular tuberculosis is the ocular involvement as a result of
-haematogenous spread from a distant site
-a direct invasion from adjacent areas like skin, sinus or cranial cavity
-as hypersensitivity response to distant infection.
? The disease is usually chronic and insidious with exacerbations &
remissions.

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PATHOPHYSIOLOGY

? Tuberculosis is caused by Mycobacterium tuberculosis
? An obligate aerobic ,slow growing ,nonspore forming ,nonmotile

bacterium

? Humans are the only natural host
? End organs with high oxygen tension (apices of the lungs , kidneys,

bones , meninges , eye ) are typically infected

? In the eyes , Choroid and Ciliary body are mainly affected

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TRANSMISSION OF INFECTION

? Primary airborne disease
? Spreads person to person : cough or sneezing
? Droplets measuring 1 to 5 micron suspended in air for several hours

can harbour the bacteria

? Usually 5 to 200 inhaled bacteria : sufficient for infection
? About 90 % of infected patients : asymptomatic

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? Epidemiology :

? Varying rates of prevalence have been reported

? World : USA ? 0.5%, Italy ? 6.31%, Japan -6.39%

? India :

? South India - 0.39%*

? North India - 9.86%**

*Biswas J, Narain S, Das D, Ganesh SK. Pattern of uveitis in a referral uveitis clinic in India. Int Ophthalmol 1996-97;20:223-228
**Singh R, Gupta V, Gupta A. Pattern of uveitis in a referral eye clinic in North India. Indian J Ophthalmol 2004;52:121?125.

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? Pathogenesis :
? Haematogenous seeding
? Primary complex
? Post primary reactivation of lung lesion ? most common
? Bacil i remain dormant for years before they are activated



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CLINICAL PRESENTATIONS

A) Adnexal manifestations

B) Anterior segment manifestations

C) Posterior segment manifestations

D) Neuro ophthalmic manifestations

E) Drug related ocular toxicity

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ADNEXAL MANIFESTATIONS

? 1) Lupus Vulgaris

? 2) Eyelid Tuberculous Granuloma

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LUPUS VULGARIS

? Unilateral , insidious
? Begins as painless , soft , reddish-brown
nodules which slowly enlarge to form
irregularly shaped red plaque and later
ulceration and scarring occur (painful ).
? Often accompanied by lymphadenopathy.
? Complications - squamous cell carcinoma
? Treatment includes ATT.

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EYELID TUBERCULOUS GRANULOMA
? Unilateral , insidious
? Manifests with a violet-brown , non-

tender, mobile nodule.

? Often accompanied by lymphadenopathy.
? The nodule may ulcerate after some time

and spread locally in an irregular fashion.

? Often accompanied by pain and discharge.
? Complications include trichiasis and

entropion.

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Anterior segment manifestations

? 1) Tuberculous conjunctivitis.
? 2) Conjunctival granuloma.
? 3) Phlyctenular keratoconjunctivitis.
? 4) Tuberculous Scleritis
? 5) Interstitial keratitis
? 6) Iridocyclitis

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TUBERCULOUS CONJUNCTIVITIS

? 1. Primary ? Unilateral
2. Secondary ? Bilateral
? Mucoid discharge, edema of lids and chemosis
? Large follicles which ulcerate
? Small, painless, and indolent ulcer,
nodule on the tarsal conjunctiva and fornix.
? Preauricular lymphadenopathy.

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CONJUNCTIVAL GRANULOMAS

? A Type IV Hypersensitivity reaction.
? Presents as an inflammatory mass on
the conjunctiva.
? It is usually occurs due to tuberculosis
but can be associated with Staphylococcus
aureus .

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PHYLYCTENULAR KERATOCONJUNCTIVITIS

? Manifests as slightly raised, small,
pinkish white or yellow nodule
surrounded by dilated vessels
on conjunctiva near the limbus
? Classically, there is no clear zone between
the limbus and the lesion.
? Is a delayed hypersensitivity reaction to
mycobacterial antigens

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INTERSTITIAL KERATITIS

? An inflammation of the corneal stroma
without primary involvement of the
epithelium or endothelium.
? In most cases, the inflammation is
an immune-mediated process triggered
by an appropriate antigen.
? Treatment- systemic antitubercular drugs,
topical steroids and cycloplegics

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TUBERCULOUS SCLERITIS

? Mostly presents as anterior scleritis

Posterior scleritis is rare .

? Localized focal elevated nodules

or Necrotizing scleritis.

? The sclera may be infected by direct spread

from a local conjunctival or choroidal lesion or
more commonly by haematogenous spread.

? This may undergo necrosis and may lead to

scleromalacia

? It does not respond to topical steroids and requires

antituberculous therapy

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ANTERIOR UVEITIS

? Acute or Chronic granulomatous

uveitis

? May be associated with iris or angle

granuloma

? Mutton fat KPs
? Posterior synechiae ?broad based

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? Iris findings
? Nodules at pupillary margin( Koeppe nodule),
? Busacca nodules
? Small gray nodules at iris root ?miliary TB
? Iris atrophy may be seen in some cases
? Severe cases, hypopyon may be seen
? Complications : cataract,glaucoma, vitritis

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INTERMEDIATE UVEITIS

? Low-grade, chronic uveitis
? Vitritis with
? - snowball opacities
? - snow banking,
? - peripheral vascular sheathing,
? - peripheral granuloma.

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Complications

? Cystoid macular edema
? Cataract
? Raised intraocular pressure
? Peripheral neovascularization
? Retinal detachment
? Vitreous haemorrhage

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POSTERIOR SEGMENT MANIFESTATIONS

? Choroidal tubercles

? Choroidal tuberculoma

? Serpiginous like choroiditis

? Subretinal abscess.

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Choroidal tubercles

? Most common manifestation
of intra-ocular tuberculosis
? Hematogenous spread
? Less than 5, upto 50 in number
? Unilateral or bilateral
? Grayish white to yellow in colour
? Indistinct borders
? Mostly in the posterior pole

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Choroidal tubercles
? Seen in miliary tuberculosis and central

nervous system tuberculosis

? Active Choroidal tubercles usually

respond well to ATT and generally take

up to 3 to 4 months to heal.

? On healing,the tubercles result in

pigmented and atrophic scars.

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CHOROIDAL TUBERCULOMA

? Choroidal tubercle continues to grow,
it forms a solitary mass known as
tuberculoma.
? Present as a solitary, yel owish,
subretinal mass with surrounding
exudative retinal detachment.
? May mimic a choroidal tumour.
? May be located anywhere
? Measures from 4 to 14 mm in size

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CHOROIDAL TUBERCULOMA

? May occur in immunocompetent
patients and in patients with
disseminated tuberculosis.
? On ultrasonography, these lesions are
solid, elevated masses with moderate
to low internal reflectivity.
? Respond well to antituberculosis
treatment.

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SERPIGINOUS LIKE CHOROIDITIS

? Chronic, progressive and recurrent

inflammation that primarily involves

the choroid and choriocapillaris.

? Progresses to involve the retina

secondarily .

? These lesions begin in the peri papillary

area and spread centrifugally.

? On progression, acquires an

active advancing edge

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? It represents an immune-mediated hypersensitivity
reaction with progression despite administration of
antitubercular treatment.
? Antituberculosis treatment in conjunction with oral
corticosteroids/immunosuppressive agents may
reduce the number of recurrences.
? The healing of such lesions may lead to peripapillary
retinochoroiditis scar.

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SUB-RETINAL ABSCESSES

? Results following liquefaction of caseous material in the
granuloma.
? Yellowish lesions associated with overlying vitritis,
retinal haemorrhages and serous retinal detachment.
? Rarely, these lesions can rupture into the vitreous cavity
and may lead to endophthalmitis or panophthalmitis

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RETINAL VASCULITIS

? Involves mainly the veins
? Characteristic feature is Periphlebitis
? Associated features
? vitreous infiltrates (vitritis)
? perivascular cuffing
? retinal haemorrhages
? neo- vascularization
? neuro-retinitis

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NEURO-OPHTHALMIC MANIFESTATIONS

? The optic neuropathy develops either from direct infection induced

by mycobacteria or from a hypersensitivity to infectious agent.

? The involvement may manifest as
? papillitis,
? retrobulbar neuritis
? neuroretinitis.

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? Clinical features

? Rapid painful loss of vision

? Vitreous haze

? Hyperemia of the disc

? Blurring of disc margins

? Optic atrophy

? Treatment

? Systemic steroids: methyl prednisolone 1g IV

? ATT

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DRUG-RELATED OCULAR TOXICITY

1. Isoniazid
? Optic neuritis
? Steven Johnson syndrome involving lids and conjunctiva
2. Rifampicin
? Orange-red discoloration of tears
3) Rifabutin
? Anterior uveitis .

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4)Ethambutol
Ocular toxic effects include
? Optic neuritis, colour vision abnormalities and visual field defects.
? Toxicity is dose and duration dependent.
? The incidence is up to 6% at a daily dose of 25 mg/kg
and rare with a daily dose not exceeding 15 mg/kg.
? Toxicity typically occurs within 3?6 months of starting treatment.

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COMPLICATIONS OF OCULAR TUBERCULOSIS

? Cataract

? Glaucoma

? Cystoid Macular oedema

? Retinal detachment

? Corneal Scarring

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DIAGNOSIS

? Confirmation of the diagnosis is a challenge since
intraocular tissue or fluids are examined rarely.
The diagnosis of ocular tuberculosis has remained largely
presumptive and dependent on associated systemic
infection.
? The diagnosis is typically made based on the clinical
presentation in conjunction with corroborative evidence,
direct evidence, and therapeutic response.

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INVESTIGATIONS

? Corroborative evidence
? Mantoux test
? Chest X RAY / CT Scan
? Serodiagnosis
? Interferon Gamma Release Assays (IGRA )
? Direct evidence
? Smear and Culture of AFB
? PCR

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? Ocular Investigations
? Fundus Fluorescein Angiography and ICG

? Optical Coherence Tomography

? Ultrasonography

? Ultrasound Bio Microscopy

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TREATMENT

? Based on evidence - Clinical
? - Indirect and direct evidence
? ATT ? drugs similar to the regimen for pulmonary
TB, with varying duration
? Corticosteroids ? Concomitant use
? Prolonged and difficult in MDR TB

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Treatment

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Treatment

? Addition of ATT to corticosteroids in uveitis patients

leads to significant reduction in recurrence.

? Systemic corticosteroids used for the first 4?6 weeks,

together with ATT, may limit damage to ocular tissues caused

from delayed type hypersensitivity.

? One should avoid using corticosteroids alone without

concomitant ATT.

? Close follow-up and monitoring of the liver function and renal

function is mandatory.

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SUMMARY

? Ocular tuberculosis involves almost all ocular structures except lens.
? Commonest manifestation is in the posterior segment.
? Diagnosis depends on clinical findings and suspicion of TB.
? Newer diagnostic modalities, IGRA and PCR are better tools in
diagnosis and for initiating antitubercular treatment.
? All patients on ATT should be screened for ocular toxicity.

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THANK YOU

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This post was last modified on 07 April 2022