Zoster Eye Disease Study: Rationale and Design

Herpes zoster in neuro-ophthalmology: a practical approach

Herpes Zoster (HZ) or shingles is the reactivation of the Varicella Zoster Virus (VZV), usually along a single sensory nerve, but can affect both sensory and motor cranial nerves. Major risk factors for HZ include immunosuppressed status and age older than 60 years. In the United States, the lifetime risk of HZ is approximately 30%. Worldwide, the median incidence of HZ is 4-4.5 per 1000 person-years across the Americas, Eurasia, and Australia. HZ ophthalmicus, occurring in 10-20% of patients, is an ophthalmic emergency characterized by VZV reactivation along the V1 branch of the trigeminal nerve. Approximately half of this patient subgroup will go on to develop ocular manifestations, requiring prompt diagnosis and management. While anterior segment complications are more common, neuro-ophthalmic manifestations are rarer and can also occur outside the context of overt HZ ophthalmicus. Neuro-ophthalmic manifestations include optic neuropathy, acute retinal necrosis or progressive outer retinal necrosis, cranial neuropathy (isolated or multiple), orbitopathy, and CNS manifestations. Although typically a clinical diagnosis, diagnosis may be aided by neuroimaging and laboratory (e.g., PCR and serology) studies. Early antiviral therapy is indicated as soon as a presumptive diagnosis of VZV is made and the role of corticosteroids remains debated. Generally, there is wide variation of prognosis with neuro-ophthalmic involvement. Vaccine-mediated prevention is recommended. In this review, we summarize neuro-ophthalmic manifestations of VZV.

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 Zoster Ophthalmicus: Presentation, Complications, Treatment, and Prevention

Herpes zoster (HZ) is caused by reactivation of latent infection of varicella zoster virus (VZV) in sensory (cranial, dorsal root) ganglia. Major risk factors for HZ are increasing age and immunosuppression. HZ ophthalmicus (HZO) is a subset of HZ with involvement of the ophthalmic division of the fifth cranial trigeminal nerve. Approximately 4-20% of patients with HZ develop HZO. Approximately 50% of patients with HZO develop ocular disease, among whom up to 25% develop chronic or recurrent disease. Common manifestations of ocular disease include conjunctivitis, keratitis, and uveitis, whereas optic neuropathy and retinitis are uncommon. Due to the potential for vision impairment, ocular involvement requires urgent ophthalmic consultation. Early recognition and timely treatment with antivirals may prevent ocular complications. HZO is preventable by vaccination against HZ. Vaccine efficacy/effectiveness studies have been largely conducted for HZ with few studies assessing HZO. Both the recombinant adjuvanted vaccine (RZV) and live-attenuated vaccine (ZVL) significantly reduce the incidence of HZ and HZO in older adults. RZV is more effective than ZVL. Data on the effectiveness of vaccines for prevention of recurrent disease in patients with HZO are limited; however, vaccination is recommended. Despite recommendations to vaccinate individuals likely to benefit from an HZ vaccine, coverage for adults remains suboptimal. Barriers to vaccination include patient beliefs about HZ or HZ vaccines, and factors related to healthcare providers. In particular, the lack of a recommendation from their primary care physician is often cited by patients as a reason for remaining unvaccinated. By encouraging vaccination against HZ, physicians not only prevent HZ and HZO but also potential vision loss due to HZO.Graphical abstract available for this article.

Herpes Zoster Ophthalmicus Recurrence: Risk Factors and Long-Term Clinical Outcomes

PURPOSE

To examine the frequency of recurrences, risk factors, and long-term clinical outcomes in subjects with herpes zoster ophthalmicus (HZO).

DESIGN

Retrospective cohort study.

METHODS

All subjects with acute HZO seen at a single center from 2006 to 2016 were included in the study. The primary outcome measure was eye disease recurrence. The secondary outcome measure was moderate vision loss (≤20/50).

RESULTS

A total of 869 patients with acute HZO were identified, with a median follow-up time of 6.3 years (interquartile range 3.7-8.9 years). In all, 551 recurrences were observed, and at least 1 recurrence was seen in 200 subjects (23.0%), with uveitis (34.8%) being the most common. The median time to first recurrence was 3.5 months. Predictors of disease recurrence included immunosuppression (P = .026), higher presenting intraocular pressure (P = .001), corneal involvement (P = .001), and uveitis (P < .001) on multivariate analysis. Topical steroids were initiated in the first month of presentation in 437 subjects, and recurrence was observed in 184 (42.1%) of these subjects. Following cessation of topical steroid treatment, recurrence occurred after a median of 1.4 months (90% within 7 months). Moderate vision loss (≤20/50) occurred in 15.5%, 28.6%, 31.4%, 50.0%, and 57.4% of eyes with 0, 1, 2, 3, and 4 or more recurrences.

CONCLUSIONS

Recurrence of HZO eye disease is common, with an increased risk of vision loss with more recurrences. These findings indicate the need for close monitoring for potential recurrences, especially after cessation of topical steroid treatment, and in individuals with identified risk factors for recurrence.

Risk of Herpes Zoster Ophthalmicus Recurrence After Recombinant Zoster Vaccination

Importance

The recombinant zoster vaccine (RZV) is currently recommended for immunocompetent adults aged 50 years or older and immunocompromised adults aged 19 years or older and is effective in preventing herpes zoster ophthalmicus (HZO). However, questions about the safety of RZV in patients with a history of HZO remain.

Objective

To evaluate whether there is an increased risk of HZO recurrence after RZV in patients with a history of HZO.

Design, Setting, and Participants

This retrospective cohort study used medical and outpatient pharmacy claims data for commercial and Medicare Advantage enrollees from the Optum Labs Data Warehouse. Patients with incident HZO from January 1, 2010, to December 31, 2021, were identified; the study period ended on March 31, 2022. The vaccinated group consisted of patients with at least 1 dose of RZV more than 90 days following the initial HZO diagnosis. The unvaccinated group consisted of patients without any record of RZV in the study period. Vaccinated and unvaccinated patients were matched using exact k:1 matching without replacement.

Exposure

Recombinant zoster vaccination.

Main Outcomes and Measures

The main outcome was the number of HZO recurrences with and without RZV exposure.

Results

A total of 16 408 patients were included in the matched analysis, of whom 12 762 were unvaccinated (7806 [61.2%] female; mean [SD] age at diagnosis, 68.8 [10.3] years) and 3646 were vaccinated (2268 [62.2%] female; mean [SD] age at diagnosis, 67.4 [9.8] years). Within the primary risk period of 56 days after the index date (ie, the start of follow-up for the outcome), the incidence of HZO recurrence after any RZV exposure was 37.7 per 1000 person-years compared with 26.2 per 1000 person-years in the unexposed group. After controlling for race and ethnicity, inpatient stays, emergency department visits, concomitant vaccines, and eye care practitioner visits, the association between vaccination status and HZO exacerbation in the primary risk period had an adjusted hazard ratio for any RZV exposure of 1.64 (95% CI, 1.01-2.67; P = .04).

Conclusions and Relevance

In this study, RZV exposure was associated with a higher likelihood of HZO recurrence in patients with a history of HZO compared with no RZV exposure. These findings support consideration that patients with a history of HZO may benefit from monitoring after receiving RZV in case of HZO recurrence.

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.

Steroids in the Management of Infectious Keratitis

PURPOSE

To summarize the evidence base on the use of topical corticosteroids for infectious keratitis.

METHODS

Narrative review.

RESULTS

Infectious keratitis is a painful condition that often results in visually significant corneal stromal scarring, even when antimicrobial therapy is successful. Corticosteroids may reduce inflammation and subsequent scar formation and while relieving the acute ocular pain associated with a corneal ulcer. However, corticosteroids also reduce the host immune response, which could hinder the ability to clear infection. The safety and effectiveness of corticosteroids depends to a large part on the efficacy of the antimicrobials being used to treat the underlying infection. Randomized trials have found that corticosteroids are safe and effective for herpetic keratitis when used with appropriate antiviral therapy, and are safe for bacterial keratitis when used with broad spectrum topical antibiotics. The effectiveness of corticosteroids for bacterial keratitis has not been shown conclusively, although more advanced bacterial corneal ulcers may do better with corticosteroids. No randomized trials have assessed the safety and effectiveness of steroids for fungal or acanthamoeba keratitis. Animal studies suggest corticosteroids may be harmful in fungal keratitis, and observational human studies have found that steroids are harmful for fungal and acanthamoeba keratitis when started prior to anti-amoebics.

CONCLUSIONS

Topical corticosteroids, when used as an adjunct to antimicrobial therapy, may be beneficial if the antimicrobial being used can effectively clear or suppress the infection, such as in bacterial and herpetic keratitis. Randomized trials would be helpful to further delineate the role of corticosteroids for infectious keratitis.

Infectious keratitis: A review

Globally, infectious keratitis is the fifth leading cause of blindness. The main predisposing factors include contact lens wear, ocular injury and ocular surface disease. Staphylococcus species, Pseudomonas aeruginosa, Fusarium species, Candida species and Acanthamoeba species are the most common causal organisms. Culture of corneal scrapes is the preferred initial test to identify the culprit organism. Polymerase chain reaction (PCR) tests and in vivo confocal microscopy can complement the diagnosis. Empiric therapy is typically commenced with fluoroquinolones, or fortified antibiotics for bacterial keratitis; topical natamycin for fungal keratitis; and polyhexamethylene biguanide or chlorhexidine for acanthamoeba keratitis. Herpes simplex keratitis is mainly diagnosed clinically; however, PCR can also be used to confirm the initial diagnosis and in atypical cases. Antivirals and topical corticosteroids are indicated depending on the corneal layer infected. Vision impairment, blindness and even loss of the eye can occur with a delay in diagnosis and inappropriate antimicrobial therapy.