Shingles, also known as herpes zoster, is a viral infection that causes a painful rash. It arises from the reactivation of the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After a chickenpox infection, VZV can remain dormant in nerve cells for years. If reactivated, the virus travels along nerve pathways, leading to a characteristic rash and symptoms.
Ocular Shingles Explained
Shingles can affect the eye, a condition termed herpes zoster ophthalmicus (HZO). This occurs when the varicella-zoster virus reactivates in the trigeminal nerve’s ophthalmic division (cranial nerve V1), which supplies sensation to the face and eye. The virus then causes symptoms in these areas. About 10% to 20% of shingles cases involve this ophthalmic division.
Recognizing Symptoms and Diagnosis
Early recognition of shingles affecting the eye is important. Initial symptoms often include tingling, burning, or shooting pain on one side of the face. This sensation is followed by a characteristic rash of fluid-filled blisters. The rash commonly develops on the forehead, eyelids, or around the eye, usually respecting the midline of the face.
Hutchinson’s sign, a rash on the tip or side of the nose, is a specific indicator. This sign indicates involvement of the nasociliary nerve, a trigeminal nerve branch that also supplies the eye, strongly indicating ocular involvement. Diagnosis is primarily made through clinical examination by a healthcare professional, often an ophthalmologist, who assesses the rash and checks for infection within the eye.
Potential Eye Complications
Ocular shingles can lead to serious eye complications, requiring prompt medical attention. Inflammation can affect various eye parts, including conjunctivitis (inflammation of the white of the eye), episcleritis, and keratitis (inflammation of the cornea). Uveitis, inflammation of the middle layer of the eye, is also a possible complication.
More severe issues can arise, such as increased intraocular pressure, potentially leading to glaucoma, which damages the optic nerve. Other vision-threatening complications include cataracts, retinal necrosis (damage to the retina), and post-herpetic neuralgia (PHN) affecting the eye area, causing persistent nerve pain. If not managed, these complications can result in permanent vision loss.
Treatment and Management
Treatment for herpes zoster ophthalmicus involves antiviral medications. These include acyclovir, valacyclovir, and famciclovir, the mainstay of therapy. For optimal effectiveness in reducing illness severity and duration, and minimizing complications, antiviral treatment should be initiated as early as possible, ideally within 72 hours of rash onset.
In addition to antivirals, supportive treatments may be used to manage symptoms. These can include pain relievers and cold compresses applied to the affected area. Specific eye drops, such as corticosteroids to reduce inflammation or lubricating drops, might be prescribed. Close monitoring by an ophthalmologist is important throughout treatment to assess eye health and manage developing complications.
Prevention Strategies
The most effective strategy for preventing shingles, including ocular shingles, is vaccination. The shingles vaccine, Shingrix, is highly effective in preventing the disease and its long-term complication, post-herpetic neuralgia. The vaccine is recommended for adults aged 50 and older. While vaccination is the primary preventive measure, supporting immune system health through general wellness practices can also reduce the risk of viral reactivation.