Ocular Manifestation of Leprosy

Leprosy

Source: Systemic kanski

Definition:

Leprosy (Hansen disease) is a chronic granulomatous infection caused by the intracellular acid-fast bacillus Mycobacterium leprae.

- which has an affinity for skin, peripheral nerves and the anterior segment of the eye.

- The exact mode of infection is unknown although the upper respiratory tract appears the most likely portal of entry.

MORPHOLOGY-

Straight / slightly curved rods

Acid fast

Gm +ve

Appears as agglomerates,being bound by a lipid substance- ‘glia’. These masses are k/as- “GLOBI” 

Parallel rows of bacilli in globi gives ‘ cigar bundle’ appear.

Clinical features:

Systemic disease manifests in two ways- 

a) Lepromatous leprosy: 

It is a multisystemic infection affecting skin, peripheral nerves, upper respiratory tract, reticuloendothelial system, eyes, bones and testes. 

Clinical manifestations include 

• Leonine facies: characterized by cutaneous thickening, nasal widening and thickening of ear lobules. 
• Saddle shape nasal deformity
• Peripheral cutaneous plques and nodules. 
• Clave hands, shortening and loss of digits 

b) Tuberculoid leprocy: 

It is restricted to the skin and peripheral nerves. 

• Annular aneasthesia 
• Hypopigmented skin lesions 
• Thickening of peripheral nerves 

1. LEPROMATOUS- cutaneous - decreased CMI - Direct ocular involvement

Lepromatous form-
Macrophages with numerous AFB [ b/o decreased CMI]

Iris pearls- Macrophages filled with bacilli

 

2. TUBERCULOID- Neural - Good CMI- Indirect ocular involvement -Neurotrophic & neuroparalytic KP

Tuberculoid form- Granuloma + Lack of large no of bacilli [ b/o good CMI]

Systemic Manifestataion: 

SKIN-

Hypopigmentation

Erhythema nodosum

Plaques & nodules

NERVES-

Skin anaesthesia

Thickened peripheral Ns

Facial palsy

DEFORMITIES-

Saddle-shaped nose

Leonine facies

Claw hand [ulnar N palsy]

Ocular manifestations: 

• Leprosy remains one of the world’s major blinding disease 
• 20% patients develop sight threatening lesions and 5 % become blind. 
• Most of the complications can be prevented if treated in time. 
• Blind leprosy patients have irreversible double tragedy. They can neither see nor feel causing great burden on himself and the relatives. 
• Lepromatous leprosy is common cause of eye complications 
• Extra ocular structures and anterior segment are commonly affect 

Anterior segment complications 

LIDS-

Madarosis

Trichiasis

Lagophthalmos

CONJ & SCLERA-

Conjunctivitis

Episcleritis 

Scleritis

CORNEA-

Neurotrophic KP

Cor anaesthesia

Keratitis

UVEA-

Acute iritis –d/t immune complex deposit

Chronic iritis- d/t direct invasion

Aq flare & cells & Fine dust –like KPs

1. Corneal complications: 

• a) Corneal anaesthesia 
• b) Keratitis 
• c) Corneal Ulcers 

· Pathogenesis: 

Corneal anaesthesia: Cornea is supplied by anterior ciliary nerves which are branches of ophthalmic division of the fifth cranial nerve. Lapromatous infiltration causes nerve thickening, causing corneal anaesthesia 

Lagophtnalmos: Lapromatous infiltration of seventh cranial nerve especially the zygomatic branch causing paralysis of the orbicularis oculi muscles. Patient is unable to close the eyes resulting in unblinking staring look with the lids wide open. 

Corneal Ulcerations: Lagophthalmos causes failure of eyelid functions like keeping the cornea clean and moist gives rise to corneal ulcerations. Due to corneal anaesthesia patient has no symptoms and the eye is neglected causing perforation of ulcer, intraocular infections and eventually blindness. 

Keratitis: Cornea is avascular and M laprae invade either from adjacent structure or along the nerves, causing micronodules. Since the cornea is transparent these nodules can be easily seen as dense white corneal pearls and causes diffuse superficial punctate keratitis. 

2. Conjunctival complications: 

• a) Chronic conjunctivitis 
• b) Lapromatous nodules 
• c) Erythema nodosum. 
• d) Pterygium

· Pathogenesis: 

Continued exposure of conjunctiva due to non-blinking eye leads to chronic conjunctivitis. 

Erythema nodosum leprosum lesions may appear on the conjunctiva. 

Pterygium, with collection of macrophages containing M. leprae has been reported. 

3. Ciliary body and iris related complications: 

• a) Iritis 
• b) Iridocyclitis 
• c) Cateract 

· Pathogenesis: 

The granulomatous lesions cause iritis and iridocyclitis. 

Chronic iridocyclitis may lead to early cataract formation. Steroids used in treatment of lepra reactions may hasten the formation of subcapsular cataract. 

Ulceration in granulomatous lesion may produce an exudate composed of fibrin and polymorphs and the pupillary margins may adhere to the anterior capsule of the lens causing posterior synechiae, resulting in fixed, narrow, non-reacting pupil. 

Eventually, destruction of the tissues of the Iris and ciliary body causes atrophy and shrinkage of the globe known as phthisis bulbi. 

Collection of lepra bacilli k/as-  IRIS PEARLS - adhere to papillary margin & iris surface like a necklace → Pearls slowly enlarge→ Coalesce → Pedunculated → Drop into AC→ disappear → iris atrophy → miosis

 

4. Episclera and sclera: 

• a) Scleritis (commonly seen) 
• b) Episcleritis (rare) 

· Pathogenesis: 

Scleritis is commonly seen in untreated patients. 

Episcleritis is rarely seen. 

Scleritis produce nodules at sclerocorneal junction and may weaken the globe. 

5. Posterior segment complications: 

• Leprosy lesions in the posterior segment are very rare. 
• There are extension of lesions from the ciliary body to the choroid and retina manifesting as yellowish nodules.

 

6. Other complications: 

• a) Madarosis: complete loss of eyebrows 
• b) Lagophthalmos: Non-blinking wide open eye 
• c) Chronic dacryocystitis 
• d) Enteropion on upper eye lid 
• e) Blepherochalasis Trichiasis: Inward turning of eye lashes

Investigations :

• Skin biopsy
• Skin test- Lepromin  test -Mitsuda reaction 
• CULTURE-
• Specimen collected from –skin, ear lobule, nasal mucosa
• Smear stained with Zeihl-Nelson stain using 5% H2SO4 acid for decolourization

Grading of smear-

1-10 bacilli / 100 fields – 1+

1-10 bacilli / 10 fields- 2+

1-10 bacilli /field       - 3+

10-100 bacilli / field -  4+

100-1000 bacilli / field – 5+

> 1000 bacilli & globi / field -6+

• Bacteriological index- Total no of + /  no of smear
• Morphological index- %  uniformly stained bacilli / total no of bacilli counted

Treatment: 

- Trichiasis- 

• Epilation
• Electrolysis-A fine electrocautery needle is passed down into the hair follicle & a current of 2 mAmp is passed
• Cryotherapy [ double freeze –thaw at -20 deg C]
• Argon laser ablation [ 50 µm. 0.2 sec, 1000mW]
• Surgery-Full-thickness wedge resection or Anterior lamellar excision

- Lagophthalmos- 

• Tarsorrhaphy

- Episcleritis- 

• Fluorometholone e/d qid
• -oral NSAIDs

- Scleritis

• oral NSAIDS
• oral steroids
• Immunosuppressants- cyclophosphomide, azathioprine,cyclosporine

- Conjunctivitis- 

• antibiotic e/d or e/o

- Keratitis- 

• Cycloplegic-mydriatic
• Analgesic
• Antibiotic e/d
• BSCL- for perforation → Tiss adhesive→ Therapeautic KP

- Iritis- 

• Topical mydriatic & steroid

-Systemic- 

• T. Dapsone 100mg /day
• Or T. Rifampicin [ 600mg]/ Clofazimin [100mg]