Corneal Scraping For C/S

Function

Corneal Scraping for Culture and Sensitivity (C/S) is a critical diagnostic procedure used to identify the specific causative agent (bacteria, fungi, or protozoa like Acanthamoeba) of a corneal ulcer or keratitis. A small sample of the infected corneal tissue is carefully 'scraped' by an ophthalmologist and placed onto various growth media to see what organism grows.

Why it is Ordered

This test is vital for sight-threatening infections. It is ordered when:

• Infection is Severe: Large or central corneal ulcers require precise identification to save the patient's vision.
• Treatment Failure: The patient is not responding to broad-spectrum antibiotic drops.
• History of Risk: The patient wears contact lenses (increased risk of Pseudomonas or Acanthamoeba) or has had vegetable matter trauma (increased risk of fungal keratitis).

Associated Conditions

The results guide the use of targeted antimicrobial therapy. Common isolates include Staphylococcus aureus, Pseudomonas aeruginosa (often aggressive), and Fusarium species. Determining 'Sensitivity' is just as important as identifying the organism, as it tells the doctor which specific antibiotics or antifungals will successfully kill the pathogen, preventing corneal perforation and permanent blindness.