If you had chickenpox as a child, you face the risk of developing shingles in adulthood. Most people who develop shingles are 50 and older. As you get older, your risk of shingles increases, with the highest incidence of shingles seen in people in their 80s.
Most often, the blistering, painful rash that accompanies shingles initially appears on one side of the torso. In 10 to 20 percent of people, shingles develops in and around one eye. This form of shingles, called herpes zoster ophthalmicus, or ocular shingles, can threaten your eyesight if not treated promptly.
What is shingles of the eye?
Shingles, also known as zoster, is caused by the varicella-zoster virus—the same virus that causes chickenpox. Once you’ve had chickenpox, the virus lies dormant in nerve tissue and can reactivate as shingles years or decades later.
Ocular shingles affects a nerve—called the fifth cranial nerve—that sends signals from the forehead and eyes to the brain. The first sign that shingles might be affecting your eyes is usually a tingling of the scalp and forehead or burning or shooting pain in the same area. These symptoms are sometimes accompanied by a fever, a headache, fatigue, and sensitivity to light in one eye.
One to three days later, a painful rash may appear anywhere from your forehead to your eyelids to the tip of your nose, where small, reddish blisters develop, which is a telltale symptom of ocular shingles. The entire rash may blister, and the pain may be acute. Other symptoms may include blurry vision and dry eye, and you can develop eye infections, including conjunctivitis (pinkeye).
If you have any signs or symptoms of shingles near your eye, it’s imperative to see an ophthalmologist immediately. Early diagnosis and treatment are critical. That’s because serious eye complications can occur with ocular shingles and threaten your vision. For example, ocular shingles can cause:
- Keratitis, an inflammation of the cornea. Sometimes, the inflammation can become so severe that it breaks down the cornea, requiring a corneal transplant.
- Iritis, an inflammation resulting in pain and swelling inside the eye.
- Optic neuritis, a swelling of the optic nerve behind the eye.
- Retinitis, an inflammation of the retina, which is known as acute retinal necrosis. It can cause retinal holes or a detached retina.
- An elevated risk of glaucoma, which can occur when ocular shingles leads to increased pressure in your eye.
Ocular shingles should be treated with oral antiviral medications like acyclovir (Zovirax), famciclovir (Famvir), or valacyclovir (Valtrex) within 72 hours of symptom onset to minimize pain, speed healing, and help avoid the risk of complications.
The drugs are typically taken for a week to 10 days. Eyedrops containing steroids can be used simultaneously to reduce inflammation, but they can cause their own complications. Because traces of the virus can remain in the cornea for as long as a month, some patients, such as those who are elderly or have a compromised immune system, may be advised to stay on the treatments longer.
For most people, the shingles rash heals and pain diminishes within three to five weeks. However, some patients will have debilitating pain that persists for three or more months, and sometimes for years. In rare cases, the pain can remain for life. This pain, called postherpetic neuralgia, is from nerve cell damage caused by the viral infection. It can often be eased by the antiseizure drugs gabapentin or pregabalin or a low-dose tricyclic antidepressant.
Several studies have linked shingles with a 1.3- to 4-fold increased risk for stroke or heart attack in the weeks and months following a bout with the disease, according to an analysis in the April 2019 issue of the Journal of Clinical Medicine. However, the link appears less pronounced among patients treated with antiviral drugs.
One study of more than 6,000 patients in the United Kingdom found that people who had ocular shingles had a threefold increased risk of stroke occurring five to 12 weeks after shingles. Some researchers hypothesize that the link may have to do in part with the inflammation caused by shingles, which can raise the risk of stroke. The virus might also invade and damage blood vessels.
A sight-saving vaccine
You’re at risk for shingles only if you’ve had chickenpox. Your best line of defense against shingles and its eye complications is the shingles vaccine. The Centers for Disease Control and Prevention (CDC) recommends that all adults over age 50 receive the new shingles vaccine Shingrix. You’ll need two Shingrix shots two to six months apart to be fully protected.
You should get the Shingrix vaccine even if you’ve already been vaccinated with the older shingles vaccine, Zostavax, since the latter’s protective effects wane with age. Shingrix was shown to be more than 90 percent effective in adults over age 50 in a study published in the New England Journal of Medicine in May 2015. And it remains 88 percent effective four years after vaccination, according to a follow-up study in the same journal in September 2016.
Shingrix has been equally effective at preventing ocular shingles, according to a review published in 2018 in BMJ. In two trials involving more than 14,000 patients, Shingrix also proved superior to placebo at preventing the virus from emerging in the eye, whereas Zostavax did not.