Herpes Zoster Ophthalmicus Increasing

When varicella-zoster virus (VZV) causes a primary chickenpox infection and remains dormant for years, the potential for reactivation is great. Older individuals may develop shingles with its characteristic fever, malaise, headache, and intensely painful lesions. Among older Americans, VZV is nearly ubiquitous. One million Americans are diagnosed with shingles annually, with the oldest, and most vulnerable most likely to be affected. VZV can develop into or present as herpes zoster ophthalmicus (HZO), and this condition is also increasing in frequency.

The journal Current Opinion in Ophthalmology includes a descriptive article that covers HZO. Authored by a faculty member at the University of California, Davis, its comprehensive coverage of the topic provides ample evidence in support of vaccination for shingles.

HZO is the presenting complaint, and up to 20% of herpes zoster cases. The causative virus most often occupies the frontal branch (the nerve servicing the forehead in the upper eyelid), but it can also inhabit both branches of the nasociliary nerve. When the latter nerve is involved, patients often have symptoms on the tip of the nose, called Hutchinson’s sign. The nasociliary nerve also innervates the cornea, conjunctiva, sclera, and uvia.

HZO, like shingles without ophthalmic manifestations, is terribly painful. It can affect any layer of the cornea, but the author notes that once the involvement is epithelial or stromal keratitis develops, risk of permanent vision loss increases. Estimates indicate that about 6% of patients may experience long-term vision loss.

Clinicians need to initiate oral antiviral therapies within 72 hours of the onset of ocular involvement. Options include

• valacyclovir here 1000 mg 3 times daily for 5 days
• famciclovir 500 mg 3 times daily for 3 days, or
• acyclovir 800 mg 3 times daily for 5 days.

All 3 antiretrovirals are considered equally effective.

If keratitis develops, no typical treatment regimen has been identified to date. Patients may respond to ganciclovir 0.15% gel. Many ophthalmologists prescribe topical corticosteroids as either ophthalmic ointments or drops, but tapering patients can be challenging. Some patients, unable to taper their doses, may need topical corticosteroids chronically, which increases risk of cataracts and steroid-induced glaucoma.

Clinicians also need to help patients deal with the pain. Although the antivirals will help mitigate the pain over time, patients will almost surely need analgesics.

Reference

Li JY. Herpes zoster ophthalmicus: acute keratitis. Curr Opin Ophthalmol. 2018;29(4):328-333.