Herpes simplex keratitis is an infection of the cornea by herpes simplex virus, usually a reactivation of an old infection. It tends to come back, and repeated scarring makes it a leading infectious cause of corneal blindness.
Key symptoms
- Red, painful eye, usually on one side
- Tearing and sensitivity to light
- Blurred vision
- Feeling of something in the eye
- Past episodes or cold sores
What you find on exam
- Visual acuity in each eye
- Fluorescein shows a branching (dendritic) ulcer with end bulbs
- Reduced corneal sensation
- Slit lamp for corneal haze or cells in the anterior chamber
Tests
- Diagnosis is mostly clinical with fluorescein and the slit lamp
- PCR of a corneal swab if the picture is unclear
- Viral culture is rarely needed
Treatment basics
- Oral acyclovir or valacyclovir, or topical ganciclovir gel
- Never give steroid drops for an epithelial ulcer
- Steroid drops only under ophthalmology for deeper (stromal) disease, with antiviral cover
- Long-term oral acyclovir to prevent frequent recurrences
- Ophthalmology follow-up within 1 to 2 days
Red flags
- Drop in vision or a white spot in the cornea
- Worsening after steroid drops
- Contact lens wearer with a corneal ulcer (possible bacterial or Acanthamoeba infection)
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations. Written by Making Synapses. Making Synapses is not affiliated with these organizations.