October 29, 2012

Herpes Virus and the Eye

By James Wymore, M.D.
Eye Surgeons Associates

The word herpes is derived from the Greek herpo, meaning “to creep.” It was apparently thought a good term for cold sores, which appeared to creep across the face. There are eight known herpes viruses that may affect the eyes. Herpes virus 1 (HSV1) and varicella-zoster virus (VZV) are the most common.

Herpes simplex 1 is frequently spread in childhood and adolescence. The primary infection will occur many times as a nonspecific upper respiratory infection. The virus then becomes dormant in deep nerves. It can reactivate in the branches of those nerves, as is well known in cold sores. The eyes may be involved—sometimes with a simple pink eye, others with a more serious inflammation on the surface of the cornea or within the eye proper.

Symptoms include blurry vision, light sensitivity, redness, and a sensation of something in the eye. The clinical course is usually self-limited, but can leave a lot of damage to the eye. For that reason, antiviral drops and oral medication are almost always used to hasten resolution or prevent vision threatening complications. The infection can return, so people who have suffered from this problem are encouraged to recheck their eyes quickly with any recurrence of symptoms. If there are multiple episodes, long term oral therapy has been very helpful in prevention.

Varicella-zoster virus causes chickenpox primarily. Similar to HSV1, after the primary infection VZV enters a period of latency in nerve roots of the body. Reactivation for this virus more completely involves a dermatome, an area of skin supplied by a specific nerve. Thus, people will suffer from shingles, a patch of skin lesions on the right or left side of their trunk or forehead and scalp. Approximately 20 percent of the population will encounter an episode of shingles at some time, and in 15 percent of those, it will affect the eye, forehead, and scalp areas. When this happens, the eyes should be checked for possible involvement.

The symptoms for VZV are essentially the same as the simplex infection, but the typical pattern of skin lesions confirms the diagnosis. Oral medication is used for shingles to reduce the incidence, severity, and duration of ocular and systemic complications and symptoms. It’s most effective when started within a few days of onset. If shingles affects the eyes, it most commonly hits the surface. Again, like HSV1, inflammation from VZV reactivation can cause enough scarring to be a blinding disease. Eye drops may be necessary to reduce that inflammation.

A vaccine, Zostavax, is now available for shingles. If there are no contraindications, it is recommended for those over 60 years of age. It decreases the risk of getting shingles about 50 percent, and subsequent neuralgia by 60 percent.

Dr. Wymore, with Eye Surgeons Associates, is a board-certified general ophthalmologist. He is a member of the American Academy of Ophthalmology. Dr. Wymore practices at our offices in Bettendorf, Iowa and Rock Island and Silvis, Illinois. For more information, please see our website: www.esaeyecare.com.