Keratitis is inflammation of the cornea. There are a number of causes of keratitis:
- Viral infection with herpes simplex
- Bacterial infection with pseudomonas or staphylococcus
- Fungal infection with candida or aspergillus
- Contact lens acute red eye (CLARE)
- Exposure keratitis is caused by inadequate eyelid coverage (e.g. eyelid ectropion)
Herpes simplex infection is the most common cause of keratitis. This is called herpes simplex keratitis. It can cause inflammation in any part of the eye however it most commonly affects the epithelial layer of the cornea. Herpes simplex keratitis can be primary or recurrent.
Herpes keratitis usually affects only the epithelial layer of the cornea. If there is inflammation of the stroma (the layer between the epithelium and endothelium), this is called stromal keratitis. This is associated with complications such as stromal necrosis, vascularisation and scarring and can lead to corneal blindness.
- Painful red eye
- Vesicles around the eye
- Foreign body sensation
- Watering eye
- Reduced visual acuity. This can vary from subtle to significant.
Staining with fluorescein will show a dendritic corneal ulcer. Dendritic describes the appearance of branching and spreading of the ulcer.
Slit-lamp examination is required to find and diagnose keratitis.
Corneal swabs or scrapings can be used to isolate the virus using a viral culture or PCR.
NICE Clinical Knowledge Summaries on red-eye say patients with potentially sight-threatening causes of red eye should be referred for same-day assessment by an ophthalmologist.
Management options in secondary care:
- Aciclovir (topical or oral)
- Ganciclovir eye gel
- Topical steroids may be used alongside antivirals to treat stromal keratitis
A corneal transplant may be required after the infection has resolved to treat corneal scarring caused by stromal keratitis.
Last updated April 2019