What Is Herpes Simplex Keratitis?

The herpes virus is best known for causing cold sores on the lips and genital herpes, but it can also cause other problems, including herpes, keratitis, also known as ocular herpes. The specific subtype that usually causes herpes keratitis is known as herpes simplex 1. As herpes simplex 1 is also the subtype that causes most cases of cold sores, herpes keratitis most often originates from a cold sore infection.

Frequency

• Herpes keratitis affects about 20,000 people for the first time in the United States each year. Another 28,000 people suffer recurrences of older infections. In Western countries, the infection is the No. 1 cause of infection-related blindness. Herpes keratitis is most common in adults.

Symptoms

• If you come down with herpes keratitis, you are likely to experience redness of the eye along with pain, redness, sensitivity to light , swelling and blurry vision. It's also common to have a watery discharge. It is an easy infection for doctors, even ophthalmologists, to miss, because the symptoms are relatively nonspecific. Typically the infection affects only the cornea's top level and heals without leaving a scar. More severe cases, however, can reach deeper tissues, especially if left untreated, and cause serious damage to the eye.

Treatment

• The first line of treatment for herpes keratitis generally involves one of three antiviral medications: acyclovir, famciclovir and valacyclovir, sold under the brand names Zovirax, Famvir and Valtrex, respectively. Taken orally or in eye-drop form, they can control the symptoms, particularly if you take them near the beginning of an outbreak. Another treatment, called debridement, involves a doctor scraping away diseased corneal tissue. The most severe cases, where scarring and vision loss occur, can require cornea transplant surgery. The herpes virus itself cannot be eradicated from the body, so recurrences are always a possibility.

Prevention

• The best way to avoid acquiring herpes keratitis is to avoid touching your eyes when you have a cold sore around the oral cavity. If you have already experienced an outbreak of herpes keratitis, you may be able to head off future outbreaks by avoiding common herpes outbreak triggers, such as stress, injury and excessive sun exposure. Contact lenses can also trigger reactivations. If you have repeated outbreaks, low dose of acyclovir, famciclovir or valacyclovir, taken daily, may reduce their frequency.

Risks

• Despite the benign course of most herpes keratitis cases, the disease is one of the most common indications for cornea transplant. It is important to seek treatment at the first sign of an ocular herpes infection. In the rare cases where it affects children, the disease is especially serious, with a higher chance of affecting both eyes, causing vision problems and recurring.