Two patients with the von Szily reaction: herpetic keratitis and contralateral retinal necrosis

The Role of Nervous System and Immune System in Herpes Zoster Ophthalmicus Dissemination and Laterality - Current Views

PURPOSE

Herpes zoster ophthalmicus (HZO) is a sight-threatening condition that is defined as HZ involving the ophthalmic division of the trigeminal nerve. Cases of bilateral HZO in recent literature question the notion of HZO being a strictly unilateral disease. Its pathogenesis is a topic of debate and current literature on VZV dissemination lacks insight into the underlying immunology. This review focuses on novel research in immunology of HZO and aims to formulate hypotheses of spread of lesions through the CNS.

METHODS

A literature search was conducted on Entrez PubMed using the search terms "bilateral" and "herpes zoster ophthalmicus". Articles on ("Immunology" or "immune cells") and "herpes zoster ophthalmicus" were also searched for. Articles published from January 1942 to April 2020 that were in English language were included.

RESULTS

Our findings revealed that hypothesised mechanisms of dissemination causing bilateral ocular disease include transmission from nerves to vessel walls, the synergistic action of the immune and nervous systems through the action of substance P and the von Szily reaction.

CONCLUSIONS

These mechanisms may be investigated using newer models of animal experimentation. It is imperative to define the molecular mechanisms behind VZV transmission to improve methods of identification, treatment, and prevention of HZO.

Case Report: Herpes Simplex Virus Type 2 Acute Retinal Necrosis With Viral Encephalitis in Children

Background

Few cases concerning acute retinal necrosis with viral encephalitis in children have been reported, especially cases where the fundus cannot be identified due to severe vitreous opacity in the early stage that makes diagnosis difficult.

Methods

We conducted a retrospective review of an unusual case of herpes simplex virus-2 (HSV-2) acute retinal necrosis with viral encephalitis in an immunocompetent child, along with a review of relevant literature published up to September 2021.

Result

An 11-year-old girl presented with an approximate 20-day history of ocular redness and decreased visual acuity in the left eye. Examination revealed anterior uveitis and vitreous opacity in the left eye. An anterior chamber tap was performed because the fundus could not be observed clearly, and the aqueous humor was positive for HSV-2 DNA. Cerebrospinal fluid also tested positive for HSV-2. She was diagnosed with acute retinal necrosis syndrome and viral encephalitis. The condition was controlled with timely antiviral and steroid therapy. She was also treated with prophylactic laser therapy to prevent retinal detachment during subsequent follow-up. The pathogenesis, diagnosis, and treatment of HSV-2 acute retinal necrosis in children and the association between acute retinal necrosis and viral encephalitis are further discussed, based on published literature.

Conclusion

HSV-2-related pediatric acute retinal necrosis may be due to the acquisition of subclinical infection with HSV-2 during parturition, followed by reactivation of the virus latent in the body on account of certain factors. Moreover, it may be complicated with viral encephalitis. For suspected cases with invisible fundus, early intraocular fluid examination is especially helpful for differential diagnosis. Early diagnosis, early treatment, and timely prophylactic laser treatment to prevent retinal detachment are key to a better prognosis. Physicians need to pay attention to such suspected cases during diagnosis and treatment.

Herpes Simplex Virus 2 Blepharokeratoconjunctivitis

PURPOSE

To retrospectively review the clinical characteristics of patients with herpes simplex virus type 2 (HSV-2) blepharokeratoconjunctivitis.

METHODS

Laboratory-proven HSV-2 blepharokeratoconjunctivitis cases were reviewed between 1995 and 2021.

RESULTS

Ten of 725 (1.4%) patients had HSV-2 infection. Data were available for nine patients. Associated conditions included neonatal herpes (1/9, 11%), severe atopy (1/9, 11%), genital herpes (2/9, 22%), and systemic immune disorders (2/9, 22%). The most common presenting finding was pain and blurred vision (55.5%). Two patients (22%) had dendritic lesions and one patient (11%) had reduced corneal sensation. Complete resolution was reported in four patients (44.5%). Recurrence was noted in four patients (44.5%) despite antiviral prophylaxis. Corneal complications included scarring and neovascularization. The visual acuity at the last follow-up was 20/40 or worse in four patients (44.5%).

CONCLUSIONS

HSV-2 is an uncommon cause of keratitis. Dendrites and loss of corneal sensation were uncommon. Recurrence was noted despite antiviral prophylaxis.

Clinical course of von Szily reaction: Case report and comprehensive review of the literature

Purpose

To describe a rare case of von Szily reaction (VSR) accompanied by a comprehensive review of the literature.

Observations

A 57-year-old woman with herpes zoster ophthalmicus (HZO) associated with ipsilateral sectoral scleritis and anterior uveitis (sclerouveitis) subsequently developed contralateral necrotizing retinitis, leading to a diagnosis of VSR. A literature review revealed 10 additional cases of VSR. The full VSR cohort of 11 subjects included six women and five men, had a median age of 39 years (range 21–78 years), and most presented with HZO (n = 7, 63.6%), often associated with either ipsilateral anterior uveitis (n = 5; 45.5%) or keratitis (n = 4; 36.4%). All 11 cases developed necrotizing retinitis in the fellow eye, at a median of six weeks following onset in the sentinel eye. The most frequently implicated agent was varicella zoster virus (VZV; n = 8, 72.7%). A high proportion of the eight patients with VZV-associated VSR were identified as having increased risk of VZV reactivation, including age of 50 years or greater (n = 5, 62.5%), an underlying malignancy (n = 3, 37.5%), and/or use of immunosuppressive medication (n = 2, 25.0%).

Conclusion

This was the first reported case of VSR presenting as HZO-associated with sclerouveitis. A comprehensive literature review revealed that most previously reported cases presented with HZO associated with isolated anterior uveitis and/or keratitis, and that all reported cases of VSR developed necrotizing retinitis in the fellow eye, typically within two months of initial presentation. Patients with VZV-associated VSR often had known risk factors for VZV reactivation.

Concomitant herpetic keratitis and acute retinal necrosis: clinical features and outcomes

BACKGROUND/OBJECTIVES

The aim of this study was to identify risk factors, prognosis, and management in patients with concomitant herpetic keratitis and acute retinal necrosis (ARN).

SUBJECTS/METHODS

In this retrospective observational series, ARN patients in the Greater Vancouver area from 2004 to 2018 were identified through key words, billing codes, and dispensing data from medical records of affiliate researchers and the pharmacy at Vancouver General Hospital.

RESULTS

Twenty-eight patients were diagnosed with ARN during this period. Five of those were also diagnosed with herpetic keratitis. Thus, the incidence of combined keratitis and ARN was 18% of patients with ARN. The two diseases occurred concomitantly in four out of five patients. Mean age at diagnosis was 55 ± 17 years. Of the five patients with both corneal and retinal involvement, three patients were immunocompromised and three had a history of herpetic diseases. Three developed disciform keratitis and two developed stromal immune keratitis. Clinical management and outcomes of these patients did not differ from patients with ARN alone, except for a lower rate of retinal detachment (p = 0.006) and a higher proportion with visual acuity ≥ 20/200 (p = 0.01).

CONCLUSIONS

Keratitis may complicate the clinical picture of one out of five to six patients with ARN. Comprehensive ophthalmic examination, including careful anterior segment exams in patients with ARN and sequential dilated fundus exams in patients with herpetic keratitis, should always be conducted to identify cases of concomitant disease.

Herpes zoster keratitis development after acute retinal necrosis

PURPOSE

To report a case of herpes zoster keratitis in a patient undergoing treatment for herpetic acute retinal necrosis.

METHODS

Case report.

RESULTS

A 71 year old male presented with acute retinal necrosis of the left eye due to herpes zoster and was treated with intravitreal foscarnet and oral valcyclovir. He developed a retinal detachment and underwent surgical repair. After four weeks, he developed an ipsilateral herpetic zoster keratitis demonstrated by Rose-Bengal staining that was responsive to topical ganciclovir gel.

CONCLUSIONS

This case report describes the unusual development of herpes zoster keratitis after the development of unilateral acute retinal necrosis (ARN) in a patient on antiviral treatment.

Herpes simplex virus type 2 mediated acute retinal necrosis in a pediatric population: case series and review

BACKGROUND

We report 15 eyes with herpes simples virus type 2 (HSV-2) mediated acute retinal necrosis (ARN) in order to better characterize pathogenesis, clinical course, diagnosis, and outcomes of the disease.

METHODS

Retrospective observational case series of 14 patients (15 eyes) all aged 21 years or younger with acute retinal necrosis resulting from HSV-2 and examined between 1995 and 2009. Patients were diagnosed by various techniques, including polymerase chain reaction (PCR) of aqueous, vitreous, and serum, antibody determination of serum and intraocular fluids, fundoscopic exam, a therapeutic trial of antivirals active against HSV-2, or a combination thereof.

RESULTS

Mean age of presentation was 11.7 years (range, newborn to 21.0 years) with a standard deviation of 7.0 years. Mean initial vision was 20/200 (median, 20/400; range, 20/20 to LP). Eleven patients (73.3 %) had received oral, injectable, or topical corticosteroids, and 14 (93.3 %) had received antiviral therapy. All patients were diagnosed based on evaluation of intraocular fluids and tissue by antibody determinations, culture, PCR, histopathologic examination, or a combination thereof. Mean final visual acuity was 20/400 (median, CF; range, 20/25 to LP) with worsened visual acuity in five eyes (33.3 %). Anatomically, 14 of 15 eyes had healed or improved retinal appearance.

CONCLUSIONS

In a pediatric population with acute retinal necrosis, HSV-2 should be considered as the prime candidate virus. Diagnosis of HSV-2 acute retinal necrosis is accomplished mainly by PCR of ocular specimens. Prompt diagnosis may lead to appropriate anti-viral therapy.

Role of nectin-1, HVEM, and PILR-alpha in HSV-2 entry into human retinal pigment epithelial cells

PURPOSE

Herpes simplex virus-type 2 (HSV-2) can cause acute retinal necrosis (ARN), which can lead to exudative and rhegmatogenous retinal detachment, yet little is known about the cellular and molecular mechanisms of HSV-2 entry into retinal pigment epithelial (RPE) cells. The goal of this study was to establish the identity of the critical receptors used by the virus for infection.

METHODS

A reporter HSV-2 virus, which expresses beta-galactosidase, was used to quantify entry into RPE cells, and viral replication was ascertained using a plaque assay. Flow cytometry and immunocytochemistry were used to determine cellular expression of entry receptors. Localization of these receptors to the apical or basal surface of RPE cells was determined with immunocytochemistry. The necessity of these receptors, individually and in combination, for viral entry was established using receptor-specific antibodies and siRNAs.

RESULTS

RPE cells are highly susceptible to HSV-2 entry and replication. Several assays demonstrated the expression of the entry receptors nectin-1, HVEM, and PILR-alpha and their localization primarily to the apical surfaces of RPE cells. Receptor-specific antibodies and siRNA knockdown of receptors significantly reduced viral entry and implicated nectin-1 as an important receptor, with HVEM and PILR-alpha potentially also contributing to entry.

CONCLUSIONS

HSV-2 is capable of developing a productive infection in RPE cells by using nectin-1 as an important entry receptor. To lesser degrees, HVEM and PILR-alpha may also contribute to HSV-2 entry into RPE cells.

Role for nectin-1 in herpes simplex virus 1 entry and spread in human retinal pigment epithelial cells

Herpes simplex virus 1 (HSV-1) demonstrates a unique ability to infect a variety of host cell types. Retinal pigment epithelial (RPE) cells form the outermost layer of the retina and provide a potential target for viral invasion and permanent vision impairment. Here we examine the initial cellular and molecular mechanisms that facilitate HSV-1 invasion of human RPE cells. High-resolution confocal microscopy demonstrated initial interaction of green fluorescent protein (GFP)-tagged virions with filopodia-like structures present on cell surfaces. Unidirectional movement of the virions on filopodia to the cell body was detected by live cell imaging of RPE cells, which demonstrated susceptibility to pH-dependent HSV-1 entry and replication. Use of RT-PCR indicated expression of nectin-1, herpes virus entry mediator (HVEM) and 3-O-sulfotransferase-3 (as a surrogate marker for 3-O-sulfated heparan sulfate). HVEM and nectin-1 expression was subsequently verified by flow cytometry. Nectin-1 expression in murine retinal tissue was also demonstrated by immunohistochemistry. Antibodies against nectin-1, but not HVEM, were able to block HSV-1 infection. Similar blocking effects were seen with a small interfering RNA construct specifically directed against nectin-1, which also blocked RPE cell fusion with HSV-1 glycoprotein-expressing Chinese hamster ovary (CHO-K1) cells. Anti-nectin-1 antibodies and F-actin depolymerizers were also successful in blocking the cytoskeletal changes that occur upon HSV-1 entry into cells. Our findings shed new light on the cellular and molecular mechanisms that help the virus to enter the cells of the inner eye.