corneal ulcer(bactrial,fungal) 25.02.16, dr.k.n.jha

Corneal UlcerDR K N Jha,MS

Professor of OphthalmologyEmail : kirtinath.jha@gmail.com

Learning AimWhat is corneal ulcer ?

Etiology, pathology, symptoms and signs

Differential diagnosis

Laboratory diagnosis

Treatment

Complications

Corneal ulcer●Loss of corneal epithelium with inflammation

in the surrounding cornea is called corneal

ulcer.

●Corneal ulcer is one the common cause of blindness.

●It is an ocular emergency.

Causative OrganismsInfections are almost always exogenous

Causative organism: S.aureus, S.epidermidis,

S. pneumoniae, Pseudomonas aeruginosa,.

Uncommon: Neisseria gonorrhoeae, E. coli

Fungi : Aspergillus and Fusarium sp

Predisposing factors • Trauma: e.g. Contact lenses, trichiasis, surgery

• Topical steroids

• Dry eye syndrome

• Lagophthalmos : e.g. Facial nerve palsy

• Neurotrophic keratitis resulting from viral infections and

lesions of ophthalmic division of Trigeminal nerve

• Deficiency states ( Vit. A ) and metabolic diseases ( DM)

• Poor local hygiene, and local infection ( chronic

dacryocystitis)

Pathogenesis of Bacterial Ulcers Bacterial adherence, proliferation, and invasion of corneal stromal lamellae

Corneal inflammation with local production of cytokines and chemokines

Diapedesis and migration of neutrophils into the peripheral cornea from limbal

vessels

Release of bacterial proteases. Enzymes released by neutrophils and activation

of matrix metallopreoteinases exacerbate inflammatory necrosis.

Healing begins with control of microbial replication.

Pathology of Corneal Ulcer• Localized necrosis of the anterior layers of the cornea

• Desquamation of the epithelium and damage to the

Bowman’s membrane

• Formation of the slough and purulent infiltration

• Regeneration of the epithelium

Clinical Features of Corneal ulcer

Symptoms : Painful red eye, diminution of

vision, photophobia

Signs: Circumcorneal congestion, ulceration,

inflammation, and necrosis of corneal layers

Fungal Corneal ulcerHistory of trauma with vegetable matter e.g.,

eye trauma during harvesting of crops.

Ulcer appears dry; it has feathery edges.

Satellite lesions may be seen.

Endothelial plaque may be visible.

Hypopyon is common.

Fungal corneal ulcer

Differential Diagnosis- Acute conjunctivitis

- Acute iridocyclitis

- Acute congestive glaucoma

Complications of Corneal Ulcer• Descematocele

• Perforation and its complications

- Anterior synechia , Iris prolapse, expulsion of lens and vitreous, Intraocular hemorrhage, Endophthalmitis / panophthalmitis

• Secondary glaucoma

• Anterior capsular cataract

• Staphyloma formation

Assessment of Corneal ulcer

History, general, and systemic examination

- Visual acuity: may be low

- Eye and Ocular adnexa: Eye lid , lacrimal sac

Conjunctiva: circumcorneal congestion

Corneal ulcer: size, site ,surface, margin, slough, corneal

sensation, thinning , satellite lesions

Anterior chamber: Cells, flare, hypopyon

Pupil

Microbiological Investigations The majority are managed without smears or

cultures.

Scraping from the ulcer margins and the base of

the ulcer

Examination of Smear stained with Gram stain,

Giemsa stain, KOH mount for fungi

Culture on blood agar, chocolate agar,

thioglycollate broth, and Sabouraud’s dextrose

agar

Management

Principles:

• Control of infection

• Symptomatic relief

• Prevention of complications

Control of InfectionTopical antibiotics

• Fortified cephazolin eye drop 50 mg / ml 1/4/6 hourly

• Fortified tobramycin eye drop 14 mg/ ml 1/4/6 hourly

Alternatives

Fortified vancomycin eye drop 25-50 mg/ml drop

Fluoroquinolone eye drop ( Cipro/ oflo/ moxifloxacin/

gatifloxacin) 0.3 % drop

Dose: 1 drop every 5-15 min for 1 hour . ½ to 1 hourly

thereafter. Reduce the dose later.

Antimicrobials for Fungal corneal ulcer

Topical antifungal drops:

- Natamycin 5 % 1 hourly by day and 2 hourly by night for 6 weeks to 6 mo

- Amphotericin B 0.15/ 0.3 % frequent instillation

Oral antifungal agents; Ketoconazole 200-600 mg/ day

Fluconazole 200-400mg/ day

Supportive TherapyCycloplegics : Atropine 1 % eye drop t.i.d.

Debridement of the ulcer

Treatment of complications: perforation,

secondary glaucoma

Outcome of corneal ulcerHealing with out

opacity

Healing with opacity

Staphyloma

Secondary glaucoma

Cataract

Phthisis bulbi

Complete healing

Point to rememberCorneal ulcer causes painful red eye.

Trauma often is the predisposing event.

Community acquired infection often does not require

microbiological work-up.

Fluoroquinolone 0.3 % eye drop 1-2 hourly, is adequate

for small, peripheral ulcers.

Atropine ointment 1% tds relieves pain, prevents

synechia.

All cases must be referred to ophthalmologist.

Can you recall ?Definition of a corneal ulcer

Causative organisms

Symptoms and Signs

Microbiological investigation

Treatment of corneal ulcer

Complications of corneal ulcer

Outcome of corneal ulcer