---
title: What is bacterial keratitis?
description: "Bacterial keratitis is an infection of the cornea caused by bacteria invading a defect in the surface, leading to inflammation, ulceration, and potential scarring. It is an ophthalmic emergency because it can rapidly threaten sight. ## Causes and Risk Factors…"
url: "https://bluefinvision.com/knowledge-base/topics/conditions-diseases/what-is-bacterial-keratitis/"
updated: "2025-12-15"
category: "Conditions & Diseases"
---

# What is bacterial keratitis?

Bacterial keratitis is an infection of the cornea caused by bacteria invading a defect in the surface, leading to inflammation, ulceration, and potential scarring. It is an ophthalmic emergency because it can rapidly threaten sight.

## Causes and Risk Factors

Common risks include contact lens wear, trauma, corneal surgery, dry eye, and ocular surface disease.

- Organisms such as Pseudomonas, Staphylococcus, and Streptococcus species are frequent culprits, particularly in contact lens users.
- Symptoms include sudden pain, redness, discharge, light sensitivity, and blurred vision.
- Examination typically shows a white corneal infiltrate, epithelial defect, and surrounding inflammation.
- Severe cases can perforate the cornea or spread inside the eye.

## Treatment

Management requires prompt intensive topical antibiotics, often after taking corneal scrapes for culture and sensitivity.

- Fortified antibiotic drops may be given hourly at first, then tapered as infection comes under control.
- Cycloplegic drops relieve pain and help prevent synechiae.
- Slow or atypical ulcers may need broadened antimicrobial cover or investigation for fungal or amoebic causes.
- Residual scarring or irregularity may require later optical correction or, rarely, corneal transplantation.