Shingles, or herpes zoster, is a viral infection known for its painful, burning, or itchy rashes. This rash appears along a particular affected nerve, such as in a band on one side of the chest or abdomen that extends around the back. In fact, the name of shingles comes from cingulum, the Latin word for belt, belt or belt.
Shingles is caused by reactivation of the varicella-zoster virus, the virus that causes chickenpox. After the initial chickenpox infection resolves, the virus lives in nerves all over the body, but is controlled by the immune system. the risk of shingles therefore increases with any process that can weaken the immune system, including age, disease, and immunosuppressive drugs. About one million cases of shingles occur in the United States each year.
Up to 20% of shingles episodes involve nerves in the head, where infection can affect various parts of the eye, including the eyelid, the surface of the eye, and the deepest parts of the eye . A viral infection of the eye can cause pain, drainage, redness, and sensitivity to light. In some cases, this can lead to visual impairment, including blindness.
Shingles at the front of the eye
Shingles can affect the cornea, the curved, transparent dome of tissue in the front of the eye. This is called keratitis and it can occur as a complication of herpes zoster ophthalmic (HZO), which refers to shingles with a rash that usually affects one side of the upper face, forehead and scalp. More than half of patients with HZO can have keratitis.
If you have shingles affecting your upper face, forehead, or scalp area, it is important to see an eye doctor for a formal eye exam, whether or not you notice eye symptoms. Keratitis usually develops within a month of the shingles rash and can lead to corneal numbness, scarring, additional infections, and more corneal damage, which can ultimately lead to blindness.
HZO, like shingles episodes in other areas of the body, is usually treated with oral antiviral drugs to treat the underlying viral infection. Treatment decreases the risk of subsequent eye complications by about 40% to 60%. When started within 72 hours of symptom onset, antiviral therapy also reduces the overall severity of infection and the risk of postherpetic neuralgia, a long-term form of pain that can occur after an episode. shingles.
Shingles at the back of the eye
Shingles involving the retina or optic nerve – structures at the back of the eye – is usually not associated with a rash or other symptoms on the surface of the eye. This type of shingles infection is called viral retinitis and occurs much less frequently than HZO. But it can significantly damage the retina through a combination of infection and inflammation. Viral retinitis can take the form of acute retinal necrosis (RNA) or progressive external retinal necrosis (PORN).
Unlike patients with HZO or other forms of shingles associated with a rash, patients with RNA are often middle-aged and generally healthy. Diagnosing RNA requires careful ophthalmologic examination by an ophthalmologist, and a sample can be taken from inside the eye to be tested to confirm that the infection is caused by the varicella zoster virus. In mild cases, RNA can be treated with oral antiviral drugs, with or without injections of antiviral drugs into the eye. In more severe cases, or if there is no improvement with oral medications and intraocular injections, these infections are treated with intravenous (IV) antiviral drugs until the infection begins to s ‘improve.
Fortunately, PORN is rare. It usually occurs in people with severely compromised immune function that progresses rapidly. PORN is treated aggressively, with intraocular injections and IV antiviral drugs.
Often, for patients with shingles, including those with HZO or RNA, efforts are made to strengthen the immune system until the infection is under control. For people taking immunosuppressive drugs, this may mean lowering the dose or giving the infection time to respond to antiviral therapy before giving another dose of immunosuppressive drugs. Sometimes the inflammation associated with shingles in the eye is so severe that steroids are needed to control the inflammation before it damages the eye.
The shingles vaccine is the best prevention
The best way to prevent shingles, including shingles in the eye, is shingles vaccine. Zostavax live shingles vaccine is no longer used in the United States. Shingrix is a newer and more effective non-living shingles vaccine. Shingrix is a two-dose vaccine recommended for adults over 50 years of age. It is over 90% effective in preventing shingles. Unfortunately, the shingles vaccine does not treat shingles or postherpetic neuralgia; the vaccine is only effective as a prevention strategy.
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