Long-Term Antiviral Therapy May Prevent Shingles-Related Vision Damage

New research led by the Perelman School of Medicine at the University of Pennsylvania and NYU Grossman School of Medicine reveals that year-long antiviral therapy can reduce the risk of eye complications from herpes zoster ophthalmicus (HZO), a serious form of shingles that affects the eye. The findings, presented at major ophthalmology conferences, provide a compelling case for long-term antiviral treatment to prevent vision loss associated with shingles.

Long-Term Therapy Shows Promising Results

The study, part of the Zoster Eye Disease Study (ZEDS), investigated the prolonged use of valacyclovir, an antiviral typically prescribed for shingles for only 7–10 days. It enrolled over 500 participants who had shingles affecting their eyes. About half of participants received daily doses of valacyclovir for a year, while the rest received a placebo. The results demonstrated that extending treatment to a year decreased the risk of new or worsening eye disease by 26% at 18 months post-treatment. Additionally, patients taking valacyclovir were 30% less likely to experience multiple HZO flare-ups over the same period compared to those receiving a placebo. The study also found that this treatment reduced chronic nerve pain associated with shingles.

Key Implications for Treatment and Prevention

HZO, which impacts approximately 100,000 of the one million annual U.S. shingles cases, can lead to severe eye inflammation, including keratitis and iritis, potentially causing significant vision loss. Roughly 30,000 patients who develop HZO experience reduced vision to 20/60 or worse, and 10,000 patients experience legal blindness (20/200 vision or worse).

“Up until now, there has been no proven long-term treatment for new, worsening, or repeated episodes of this disease, so the results of this study provide convincing evidence for using long-term, low-dose antiviral treatment,” said Dr. Bennie Jeng, co-chair of the study. With valacyclovir already being a standard short-term therapy for shingles, researchers believe that its extended use could be a feasible, low-barrier option to protect vision and improve outcomes for patients with HZO. 

The study also underscored the importance of shingles vaccination, particularly for individuals aged 50 and older, as prevention remains the most effective strategy. Despite recommendations for vaccination since 2018, only 12% of this population has received the zoster vaccine. Lead investigator Elisabeth J. Cohen, MD, emphasized that “prevention is even more effective than any treatment.” 

Future Directions in Shingles Research 

Moving forward, researchers will examine whether long-term antiviral treatment lowers the risk of other complications like glaucoma and scleritis. They also aim to investigate the impact of shingles vaccination on the study’s participants, including the relationship between shingles vaccination and outcomes related to COVID-19 diagnosis and severity.