Ocular Herpes (Herpes of the Eye)

Herpes viruses can cause not only cold sores but can also affect the eyes. In the eye, a herpes infection can involve the eyelids, the cornea, the iris, and in rare cases even the retina. Early detection and treatment are crucial to prevent lasting damage to vision.

Which herpes viruses affect the eye?

Herpes simplex virus (HSV): the same virus that causes cold sores (HSV-1). It can be transmitted to the eye, for example by touching an active blister and then rubbing the eyes. HSV eye infections are the most common form of ocular herpes.
Varicella-zoster virus (VZV): this virus causes chickenpox and can be reactivated as shingles (herpes zoster). When shingles affects the eye nerve (ophthalmic nerve), it is called herpes zoster ophthalmicus – a condition that is more common in adults and can cause serious complications.

Symptoms

The symptoms depend on which part of the eye is affected:

Eyelid blisters: small, painful blisters on the eyelid skin or at the eyelid margin
Corneal inflammation (keratitis): redness, pain, light sensitivity, foreign-body sensation, blurred vision, and watering. A tree-shaped ulcer on the cornea (dendritic keratitis) is typical.
Iris inflammation (iritis): dull eye pain, light sensitivity, red eye
Retinal involvement (rare): sudden deterioration of vision, flashes of light

Diagnosis

The ophthalmologist usually makes the diagnosis based on the typical appearance under the slit lamp. When the cornea is involved, staining with fluorescein reveals the characteristic pattern of the herpes ulcer. In unclear cases, laboratory tests (swab, PCR) can confirm the diagnosis.

Treatment of Ocular Herpes

Antiviral medication: depending on severity, antiviral eye ointments (e.g. aciclovir), eye drops, or tablets are used. In herpes zoster ophthalmicus, systemic antiviral medication (tablets) is particularly important.
Anti-inflammatory drops: when the iris or deeper corneal layers are involved, cortisone-containing eye drops may be necessary – but only under strict ophthalmological supervision, since cortisone can further damage the cornea during active herpes.
Pupil-dilating drops: they relieve pain and prevent the iris from sticking to the lens.
Pressure-lowering drops: if the intraocular pressure rises, pressure-lowering eye drops are used in addition.

Recurrences

After the initial infection, herpes viruses remain in the body for life (in nerve ganglia) and can be reactivated at any time. Triggers for recurrences include stress, fever, strong sunlight, injuries, or a weakened immune system. Some patients need ongoing low-dose antiviral therapy to prevent frequent recurrences.

Possible complications

Corneal scars with permanent reduction in vision
Chronic inflammation of the cornea or iris
Raised intraocular pressure (glaucoma)
In rare cases, a corneal transplant is required

When should you seek medical help?

If you have redness, pain, light sensitivity, or blurred vision, especially if blisters are present at the same time on the eyelid or face, you should see an ophthalmologist promptly. Ocular herpes is not an emergency that can wait for hours: the sooner treatment begins, the better the prognosis.