Herpes simplex (cold sore) virus (HSV)

This is a common infection. It  causes keratitis (inflammation and ulceration of the cornea), iritis, and cyclitis. In immunocompromised people it is especially serious.


By skin or mucous membrane contact with a person with HSV.

Types of HSV

HSV-1: orofacial
HSV-2: genital

Both types can cause ocular disease


After initial infection, which often has no symptoms, the virus lies dormant in a large nerve called the trigeminal nerve in the head. Reactivation of the virus may occur months to years later.


This may be triggered by a number of factors shown below. In most cases, however, there is no consistent trigger factor

Sun exposure
Surgery eg. corneal graft, laser surgery to eye

Within one year of primary infection, 10-25% of patients have a recurrence. Those who have had one recurrence are more likely to have further recurrences.

Symptoms of infection outside the eye

Characteristic skin eruptions, especially around the mouth, lips and eyes. These usually resolve on topical aciclovir [Zovirax] ointment which in the United Kingdom is available without prescription.

Symptoms of infection in the eye

Painful red eye
Loss of visual acuity
Photophobia (sensitivity to light)

Less common symptoms are:

Conjunctivitis (sticky eyes)
Blepharitis (inflammation of the eyelids)

If you have had HSV in the past, and you have these symptoms, you should see an ophthalmologist.

Signs which an ophthalmologist would look for

(Do not worry if you do not understand the technical terms)

Dendritic keratitis (dendritic ulcer)
Stromal (disciform) keratitis
Non-granulomatous keratic precipitates
Iris atrophy (uncommon)
Raised intraocular pressure


The diagnosis is usually made on the history of previous cold sores and the characteristic appearance of the eye (especially where there is a dendritic keratitis). Scrapings of cornea and conjunctiva for viral culture may be useful in cases where the diagnosis is suspect.


Aciclovir 3% eye ointment 5x/day
Steroid eye drops (eg. Prednisolone [PredForte, Predsol], Dexamethasone [Maxidex]) may be used if there is severe iritis
Cycloplegics to enlarge the pupil (eg. Cyclopentolate, Atropine)
Pressure-lowering drops (numerous) if the pressure is raised

In very severe cases with permanent corneal scarring, a corneal transplant may be considered to restore vision.

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