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.
