Gelston, Christopher D.

Importance High-quality evidence regarding suppressive valacyclovir treatment in herpes zoster ophthalmicus (HZO) is necessary to guide care. Objective To determine whether suppressive valacyclovir compared with placebo delays the occurrence of new or worsening stromal keratitis (SK), endothelial keratitis (EK), iritis, or dendriform epithelial keratitis (DEK) during 12 months of treatment and if treatment benefit persisted at 18 months (secondary end point). Design, Setting, and Participants The Zoster Eye Disease Study (ZEDS) was a randomized clinical trial conducted in 95 sites from November 2017 to June 2024. Immunocompetent, nonpregnant adults with a history of an HZO rash, documented active keratitis or iritis within 1 year, and an estimated glomerular filtration rate of 45 mL/min/1.73 m 2 or greater were eligible. After determined to be eligible, participants were randomized in 4 strata: age at onset (<60 years vs ≥60 years) and disease duration (<6 months vs ≥6 months). Interventions A total of 12 months of double-masked daily valacyclovir, 1000 mg, or placebo. Main Outcomes and Measures The primary outcome was time to first occurrence within 12 months of new or worsening SK, EK, iritis, or DEK. Results A total of 527 participants (median [IQR] age, 60 [50-68] years; 266 female [50.5%]; 266 in the valacyclovir group; 261 in the placebo group) were randomized in 4 strata; 481 completed 12 months, and 460 completed 18 months. Data were analyzed by intention to treat. At 12 months, primary end points occurred in 86 participants (33%) assigned to placebo and 74 (28%) assigned to valacyclovir, and at 18 months in 104 participants (40%) assigned to placebo and 86 (32%) assigned to valacyclovir. The hazard ratio (HR) of the primary end point at 12 months was 0.77 for participants taking valacyclovir vs placebo (HR, 0.77; adjusted 95% CI, 0.56-1.05; P = .09) and 0.73 at the secondary end point at 18 months (HR, 0.73; adjusted 95% CI, 0.55-0.97; P = .03). There was a reduction of multiple other secondary end points at 12 months (HR, 0.70; 95% CI, 0.52-0.95; P = .02) and 18 months (HR, 0.72; 95% CI, 0.55-0.95; P = .02). Conclusions and Relevance Although the primary outcome did not show a benefit of suppressive valacyclovir treatment, secondary study outcomes showed treatment superiority at the 18-month end point and reduced number of multiple episodes of keratitis or iritis at both 12 and 18 months. These results support consideration of 1 year of suppressive valacyclovir treatment for HZO. Trial Registration ClinicalTrials.gov Identifier: NCT03134196

Importance Evidence regarding suppressive valacyclovir treatment on postherpetic neuralgia is necessary to guide care. Objective To test the hypothesis that suppressive treatment with 1000 mg/d of oral valacyclovir for 12 months reduces the prevalence, severity, and duration of postherpetic neuralgia compared with placebo at 12 and 18 months in participants with herpes zoster ophthalmicus (HZO). Design, Setting, and Participants Multicenter, placebo-controlled randomized clinical trial including 527 immunocompetent, nonpregnant adults with history of HZO rash, documented keratitis, or iritis within 1 year and an estimated glomerular filtration rate of 45 mL/min/1.73 m 2 or greater. The study was conducted at 95 participating sites (in Canada, New Zealand, and the US) from November 2017 to June 2024 and participant visits occurred every 3 months. Intervention Treatment with 1000 mg/d of valacyclovir or placebo for 12 months. Main Outcomes and Measures Prevalence of postherpetic neuralgia, severity as determined by pain score (a score of ≥3 on a scale of 1-10), pain duration (≥3 months after HZO onset), and total daily dose of pain medication. Results Of the 527 participants (490 completed 12 months of treatment and 460 completed 18 months), 73 (14%) had postherpetic neuralgia and were analyzed by age at HZO onset (<60 years or ≥60 years) and disease duration (recent [<6 months] or chronic [≥6 months]). Of the 73 participants with postherpetic neuralgia (34 in the valacyclovir group and 39 in the placebo group), the mean age was 62.4 years (SD, 13.6 years), 59% were female, 5% were Black or African American, and 10% were Hispanic. The prevalence of postherpetic neuralgia at 12 months was not reduced by valacyclovir (12/32 [38%]) compared with placebo (14/35 [40%]) (between-group difference, 2.5% [95% CI, −20.8% to 25.8%]; P >.99). The participants who were younger than 60 years at HZO onset and had a chronic disease duration had lower pain scores in the valacyclovir group (mean score, 0.3 [SD, 0.9]) vs the placebo group (mean score, 0.8 [SD, 1.9]) at 12 months ( P = .045) and at 18 months (mean score, 0.2 [SD, 0.9] vs 1.0 [SD, 2.3], respectively; P = .02). There was a decrease in pain duration in the valacyclovir group at 18 months (mean, 13.6 [SD, 11.4] months) vs the placebo group (mean, 18.7 [SD, 29.5] months) (linear mixed-effects model between-group difference, −3.39 months [95% CI, −6.73 to −0.04 months]; P = .046). The total daily dose of neuropathic pain medication was lower in the valacyclovir group (mean, 271.4 [SD, 593.8] mg/d) vs the placebo group (mean, 363.4 [SD, 592.2] mg/d) at 12 months (linear mixed-effects model P = .006) and at 18 months (mean, 209.0 [SD, 412.8] mg/d vs 286.2 [SD, 577.9] mg/d, respectively; linear mixed-effects model P = .01). Conclusions and Relevance One year of suppressive treatment with valacyclovir was associated with a lower dosage of neuropathic pain medication. Participants in the valacyclovir group, who were younger at HZO onset and had a chronic disease duration, had lower pain scores. These secondary outcomes support consideration of 1 year of suppressive treatment with valacyclovir to reduce dosage of pain medications and pain due to HZO. Trial Registration ClinicalTrials.gov Identifier: NCT03134196