Enrollment in the Zoster Eye Disease Study

Low-Dose Valacyclovir for Postherpetic Neuralgia in the Zoster Eye Disease Study: A Randomized Clinical Trial

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 m2 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.

Low-Dose Valacyclovir in Herpes Zoster Ophthalmicus: The Zoster Eye Disease Randomized Clinical Trial

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 m2 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.

Clinical strategies to prevent recurrence of Herpes simplex and Herpes zoster following ocular surgery: A comprehensive review with practical guidelines

Recurrences of herpetic infections following intraocular surgeries pose a threat to optimal surgical outcomes. The high prevalence of herpetic diseases require ophthalmologists to be familiar with the special measures in the surgery of these patients. A thorough preoperative assessment and meticulous postoperative surveillance should be tailored for each patient, depending on the surgery and the risk of virus reactivation. We compile the relevant evidence in the literature and provide a comprehensive review of the preoperative assessment and postoperative diagnostic clues and management of the herpetic infections following different types of intraocular surgeries, including cataract surgery, keratoplasty, corneal crosslinking, glaucoma, and refractive surgeries.

Baseline Participant Characteristics at Enrollment in the Zoster Eye Disease Study

PURPOSE

The Zoster Eye Disease Study (ZEDS) is the first randomized clinical trial to study the efficacy of long-term (1 year) suppressive valacyclovir treatment on herpes zoster ophthalmicus (HZO) outcomes. This article details the baseline characteristics of participants.

METHODS

SETTING

The study was set at 95 participating clinical centers in 33 states, Canada, and New Zealand.

STUDY POPULATION

Immunocompetent adults with a history of a characteristic HZO unilateral rash and documentation of an episode of active dendriform epithelial keratitis, stromal keratitis, endothelial keratitis, or iritis within the preceding year, enrolled in ZEDS from November 2017 to January 2023.

INTERVENTION

Participants were randomized to double-masked oral valacyclovir 1 gm daily versus placebo for 1 year of treatment and followed for 18 months.

RESULTS

Five hundred twenty-seven participants were enrolled across 4 strata according to age at HZO onset (younger or older than 60 years) and duration of HZO at enrollment (less or greater than 6 months), with an even distribution of men and women and a median age of 60 years. More participants with recent (57%, 300/527) than chronic HZO and younger than 60 years at HZO onset (54%, 286/527) were enrolled. Most participants were treated acutely with a recommended antiviral regimen (91%, 480/527) and had not been vaccinated against zoster (79%, 418/527).

CONCLUSIONS

The broad ZEDS study population enhances the likelihood that ZEDS will provide generalizable high-quality evidence regarding the efficacy and safety of suppressive valacyclovir for HZO immunocompetent adults and whether it should become standard of care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03134196.

Characteristics of Prescreened Patients Who Did Not Participate in the Zoster Eye Disease Study

PURPOSE

The Zoster Eye Disease Study (ZEDS) is a multicenter randomized clinical trial (RCT) funded by the National Eye Institute aiming to determine the efficacy of suppressive valacyclovir treatment in herpes zoster ophthalmicus (HZO) that enrolled fewer participants than planned (527/780, 67.6%). Understanding reasons for nonparticipation of likely eligible prescreened patients provides insights into patient populations that are not represented by ZEDS and barriers in clinical trials.

METHODS

In this retrospective cohort study, HZO adults likely eligible for ZEDS with a history of a typical rash and a medical record within the past year of an episode of epithelial or stromal keratitis or iritis were prescreened at activated Participating Clinical Centers from 2017 to 2022 using a standard prescreening log. De-identified data including demographic information, reasons for exclusion because of ineligibility, and patient refusal were retrospectively entered into REDCap and analyzed.

RESULTS

Prescreening logs with reasons for nonconsent (1244/1706, 72.9%) were included in the data set. Patients were excluded from the study (915/1244, 73.6%) because they did not meet all inclusion criteria (619/915, 67.7%) or met an exclusion criterion (296/915, 32.3%). Among the 12 exclusion criteria for the ZEDS study, immunocompromise (76/296, 25.7%) and renal insufficiency (50/296, 16.9%) were most frequently reported. Patient refusal to participate (327/1,244, 26.3%) was common.

CONCLUSION

The most common reasons for ineligibility were immunocompromise and renal insufficiency. There may be benefits to long-term antiviral use in these populations not captured in ZEDS. A quarter (26.3%) of prescreened patients refused participation, showing the substantial impact of patient preferences on trial participation.

Herpes simplex virus, varicella-zoster virus and cytomegalovirus keratitis: Facts for the clinician

Keratitis due to Herpes simplex virus (HSK), Varicella-Zoster virus (VZK) and Cytomegalovirus remains a frequent source of concern for many ophthalmologists. They are a frequent cause of emergency consultations at eye care centers and carry the risk of permanent loss of visual acuity or visual quality and/or chronic neurotrophic keratitis, resulting in a significant decrease in the quality of life. HSK and VZK can affect the corneal epithelium, stroma, or endothelium or a combination of layers. In contrast, most cases of CMV keratitis present as isolated endothelitis (CMVE), a clinical entity that has been described within the last 2 decades. These three types of viral keratitis are characterized by a high frequency of recurrences and each new episode increases the risk of sequelae. Hence, ophthalmologists must adapt the treatment to the clinical presentation of each recurrent episode in order to mitigate the immediate consequences of viral replication and the immune response on corneal transparency. In patients with frequent recurrences, preventive long-term antiviral treatment is strongly recommended. However, in some rare cases, continuous exposure to antivirals may promote the emergence of resistant viral strains, which can be difficult to manage. In the future, the introduction of new antiviral drugs, with differing modes of action compared to current medical therapy, could be an alternative until a truly effective preventive solution, such as a vaccine, is available.

Zoster Eye Disease Study: Rationale and Design

PURPOSE

The purpose of this study was to describe the rationale and design of the Zoster Eye Disease Study (ZEDS).

METHODS

ZEDS is a National Eye Institute-supported randomized clinical trial designed to determine whether 1 year of suppressive valacyclovir in patients with herpes zoster ophthalmicus (HZO) reduces complications because there is currently no high-quality evidence to support its use. Eligible patients are 18 years and older, immunocompetent, have a history of a typical rash at disease onset, and have had a record of active epithelial or stromal keratitis or iritis within 1 year before enrollment. Exclusion criteria include estimated glomerular filtration rate less than 45 or pregnancy. The primary endpoint is the time to first occurrence of new or worsening dendriform epithelial keratitis, stromal keratitis without or with ulceration, endothelial keratitis, or iritis due to HZO during 12 months of study treatment requiring prespecified treatment changes. The study has 80% power to detect a 30% difference between treatment groups, with a 30% rate of endpoints by 1 year assumed among controls. Secondary and exploratory questions include whether there is a persistent treatment benefit during the 6 months after treatment, whether development of postherpetic neuralgia varies by treatment group, and whether vaccinations against herpes zoster affect study outcomes and coronavirus disease 19 status.

RESULTS

Over approximately 4 years, over 400 study participants have been enrolled.

CONCLUSIONS

ZEDS aims to provide scientific evidence on whether suppressive valacyclovir treatment improves outcomes in HZO and should become the standard of care.

Herpes Zoster: A Brief Definitive Review

ABSTRACT

This brief definitive review of herpes zoster (HZ) will cover the current state of knowledge and questions that remain to be answered regarding HZ in general and HZ ophthalmicus in particular. A question-and-answer format will be used to address various important topics related to this common and serious disease. Questions to be addressed relate to common misconceptions, contagiousness of infection, unknowns regarding pathogenesis, rising incidence, risk factors and complications, relationship with temporal arteritis, vaccination, and current and future antiviral treatment. In addition, the importance of the Zoster Eye Disease Study to determine the efficacy of suppressive valacyclovir treatment in preventing complications of HZ ophthalmicus and the need to support enrollment will be discussed.