AAO 2024: Main takeaways from the Zoster Eye Disease study

At this year's American Academy of Ophthalmology congress, Elizabeth Cohen, MD, discussed recent findings from the Zoster Eye Disease study. Here are her highlights from the research, which focused on suppressive valacyclovir use and results for patients with keratitis and iritis.

Editor's note: The below transcript has been lightly edited for clarity.

Elizabeth Cohen, MD: My name is Elizabeth Cohen, and I am Professor and Vice Chair of the Department of Ophthalmology at NYU Grossman School of Medicine, NYU Langone Health. So the Zoster Eye Disease study has just come out with its results, and the main takeaways are that if we treat patients or study participants who have shingles in the eye and have eye involvement, and we put them on a low dose of valacyclovir, 1000 milligrams daily for a year, we will reduce the likelihood of flare ups of their keratitis or iritis, statistically significant at 18 months. In addition, at both 12 and 18 months, we prevent people from having multiple flare ups of keratitis or iritis, which is very important, because those people can go on to chronic and recurrent disease and loss of vision.

The other take home point is that we look to see the benefit for this treatment with regard to post-herpetic neuralgia of chronic pain syndrome, as well as pain-related shingles, and we found very significantly that treatment with low dose of valacyclovir reduces the need for neuropathic pain medicine, which are very poorly tolerated. They make people tired, and valacyclovir is much better tolerated. There also were other benefits with regard to the amount of pain, the duration of pain, and the prevalence of postherpetic neurology in some groups, but overall, the biggest benefit with regard to pain was reducing the need for these pain medicines. So we really hope that ophthalmologists will lead the way and that their doctors will evaluate the use of suppressive valacyclovir to reduce pain related to Zoster in other locations.

...This study was modeled after the Herpetic Eye Disease Study, [an] acyclovir prevention trial that looked at low-dose acyclovir for reducing recurrences of herpes simplex virus disease, and we use the same approach to study herpes zoster caused by a different herpes virus, the varicella zoster virus. And in the head study on HSV disease, there was benefit at 12 months, but not at 18 months. And here we saw a greater benefit at 18 months, both regarding the eye as well as regarding the pain. So that was a little surprising, in how much—the difference in benefit for the eye wasn't that great, but enough of a difference to be between statistically significant and not significantly significant. So we still think there's benefit, period, for the eye manifestations, with regard to the post herpetic neuralgia and the pain, 12 and 18 months were equal endpoints, whereas for the eye problem, 12 months was the primary endpoint. So with regard to the pain, I think the greater benefit at 18 months may be because it takes nerves that are injured and inflamed time to heal. And when I'm asking myself, "Why do we have greater benefit with the eye disease," the benefit wasn't that much greater, but it also we had a lot of a number of early endpoints around 3 months into the study, and it may take more time for the suppressive treatment to kick in its benefits.