Management of Bacterial CORNEAL ULCERS

This CME of the Jablapur Divisional Ophthalmic Society was held on the 18th of Septemeber 2005 at Hotel Krishna, the High Tea session was sponsored by Allergan India Ltd.

Presented by-
Dr ATUL SHARMA
Padma Eye Care Hospital

Introduction

• Break in corneal integrity with underlying stromal infiltrate
• Significant cause of visual impairment
• Infection is mainly responsible in majority cases
  

Etiology

• Almost any organism can invade cornea if corneal defense machenism compromised
  
• Lid abnormality
  
• Tear Film abnormalities
  
• Compromised corneal epithelium
  
• Developed countries- Viral infection
  
• Developing countries- Bacterial, Fungi, Acanthamoeba
  
• In a study - 71.9% culture positive
  
• 63.9%- Bacterial , 2.1% - Parasitic
  
• 33% - Fungal , 6.2% - Mixed infection
  

Organisms Profile

• Gram + cocci-
  
  • Staph. Epidermidis (32.4%), Strept. Pneum(13.1%)
    
  • Staph aureus(7.6%).
    
• Gram + Bacilli
  
  • Corynebacterium(13.9%)
    
• Gram - Bacilli
  
  • Pseudomonas(11.1%)
    
• Fungal
  
  • Aspergillus(33%), Furarium(35.1%)
    
• Parasite
  
  • Acanthamoeba
    

Probable Etiological Diagnosis

• No Distinctive sign to identify responsible organism
  
• Gram + cocci
  
  • Localized round & oval ulceration
    
  • Grayish white stromal infiltrate with distinct border
    
  • Minimal surrounding haze
    
• Gram - bacilli
  
  • Rapid inflammatory destructive course
    
  • Dense stromal suppuration
    
  • Hazy surrounding cornea with ground glass appearance
    
• Fungal Keratitis
  
  • Dry raised slough
    
  • Stromal infiltrate with feathery edge
    
  • Satellite lesion
    
  • Thick endothelial exudates
    
• Acanthamoeba
  
  • Epithelial irregularities, single or multiple
    
  • Stromal infiltrate
    
  • Classical ring shaped configuration
    
  • Severe pain & keratoneuritis
    

LAB Investigations

Routine systemic investigation

Smears (Staining)

• Conjunctiva, Sac -- Gram + Geimsa,
  
• Corneal ulcer(from scraping) -- Gram, Geimsa, KOH, Methenamine silver stain, calcoflour white flourescent dye
  
• Culture for Corneal ulcer [ protocol ]
  
• Lid margin -- Bl Agar, En chocolate agar
  
• Conjunctiva -- Bl Agar, En chocolate agar
  
• Sac -- Bl Agar, Br Ht infusion
  
• Anaerobic -- Thioglycate, CO2 media

Corneal ulcer (Scrapings)

• Moist swab culourette
  
• Klmura spatula- Bl Agar, En chocolate agar, Sabouraud's media, Br Ht infusion

A study shows - Despite a tendency towards favorable results in culture positive corneal ulcers, the influence of detection of organism on their outcome has not been proved. The role of initial antibiotics therapy remain important.

Treatment

Local

Mono-therapy drops - Fluoroquinolones, Aminoglycosides, Tetracyclines, Chloramphenicol

Fortified antibiotics drops - Cephalosporins, Macrolides, glycopeptides, Lincomycin

Lubricating eye drops

Cycloplegics (Atropine)

Oral

Penicillins,Tetracyclins, Sulphonamides

Sub-conjunctival Injection

Aminoglycosides, Fluoroquinolones

Microbiological investigation always done in following-

Severe ulcers(rapidly progressing infiltrate >6 mm)

Involving deeper stoma

Associated with imminent or actual perforation

Cases with H/O & clin. Exam suggestive of unusual pathogen

Supplementary t/t -

Cycloplegic agents
Antiglaucoma agents
Oral analgesics

Surgical t/t

Debridement of necrotic debris

Tissue adhesives with bandage contact lens

Amniotic membrane graft

Conjunctival flap

Mucous membrane flaps

Lamellar & Penetrating keratoplasty

Table: Anti-biotics used in the treatment of Corneal Ulcers:

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