High prevalence of herpes simplex virus type 2 in acute retinal necrosis syndrome associated with herpes simplex virus in Japan

Common Practice Patterns in the Diagnosis and Management of Acute Retinal Necrosis: A Survey Study of Uveitis Specialists

PURPOSE

Due to lack of large randomized clinical trials to determine best practices in treating acute retinal necrosis (ARN), there is not a clear consensus amongst ophthalmologists on how to best manage this potentially blinding condition. The aim of this study is to survey common practice patterns and analyze the factors that affect ophthalmologists' management of ARN.

METHODS

An anonymous survey was distributed to uveitis and retina specialists who are members of the American Uveitis Society (AUS) via email to query practice patterns regarding ARN. The survey included 22 questions with an additional 10 questions based on response. Survey question topics included demographic information, diagnostic testing, antiviral therapy, corticosteroids, and surgical procedures.

RESULTS

67 surveys were included for analysis. Most respondents (87%) always or frequently obtain intraocular aqueous fluid for diagnostic PCR testing. The majority of respondents would administer intravitreal antiviral injections to a unilateral immunocompetent ARN patient (67%), but would be even more likely to do so for a bilateral immunosuppressed ARN patient (87%). Respondents tend to treat ARN with systemic rather than local corticosteroids, with the majority (63%) of respondents initiating corticosteroid treatment 48 hours after treatment. Most respondents (79%) never perform a vitrectomy to manage ARN unless the patient has a retinal detachment or tear. The majority (63%) rarely or never perform prophylactic laser barricade, but may consider laser treatment if there is extensive retinal involvement.

CONCLUSION

Current practice patterns for diagnosis and management of ARN among AUS members generally align with the suggested practices outlined by the American Academy of Ophthalmology.

Role of Recent PCR Tests for Infectious Ocular Diseases: From Laboratory-Based Studies to the Clinic

Infectious uveitis is a vision-threatening condition that requires prompt clinical diagnosis and proper treatment. However, rapid and proper diagnosis in infectious uveitis remains challenging. Several examination tests, including polymerase chain reaction (PCR) tests, are transitioning from laboratory-based basic research-level tests to bedside clinical tests, and recently tests have changed to where they can be performed right next to clinicians. In this review, we introduce an updated overview of recent studies that are representative of the current trends in clinical microbiological techniques including PCR tests for infectious uveitis.

Long-term follow-up of acute retinal necrosis with retinal detachment secondary to herpes simplex virus type 2 with a successful visual outcome

A man in his early 20s presented with acute loss of vision in his only eye, the left eye (OS), and was on oral steroids. He had lost vision in his right eye during his childhood and the cause was unknown. There was no history of trauma. Best-corrected visual acuity (BCVA) in OS was 20/100 and in the right eye was hand movements. OS showed non-granulomatous keratic precipitates on the cornea, anterior chamber flare 1+ and cell 1+, early cataract, vitreous haze and cells 2+ with nasal retinal detachment and superior full thickness retinitis. He underwent pars plana vitrectomy with intravitreal ganciclovir and barrage laser away from the necrotic retina. PCR for herpes simplex virus 2 was positive from the aqueous and vitreous sample. He was started on oral valacyclovir 1 g three times a day and continued on tapering dose of oral steroids. BCVA in OS at 6-month follow-up was 20/25.

Advances in the microbiological diagnosis of herpetic retinitis

Viral retinitis associated with herpesvirus is one of the most severe forms of uveitis and is a potentially sight-threatening ophthalmologic disease. The prognosis is poor and a rapid and aggressive management is necessary to improve the visual and sometimes vital prognosis of these patients. The treatments used are not without side effects, while many differential diagnoses exist, such as toxoplasmic retinochoroiditis, syphilitic retinitis, endogenous endophthalmitis and intraocular lymphoma. Causatives viruses are herpes simplex virus, varicella-zoster virus, and cytomegalovirus, which require rapid detection in ocular fluid, mainly aqueous humor. However, only a small amount of intraocular fluid is available for analysis. Advances in microbiological diagnostic techniques therefore were key factors in improving the management of these diseases. Historically, the diagnosis was based on immunological tests but more recently advances in molecular biology, in particular polymerase chain reaction, have played a crucial role to obtain a reliable and rapid diagnosis of viral retinitis associated with herpesvirus, as discussed in this review.

Anterior segment involvement in Epstein-Barr virus: a review

The aim of this study is to describe the involvement of Epstein-Barr Virus (EBV) in the diseases of the ocular anterior segment. This is a narrative review designed using the PUBMED, SCOPE and Web of Science databases, searching for reported literature on findings in the anterior ocular segment related to EBV between 1990 and 2020. Epstein-Barr Virus (EBV) is implicated in the development of salmon-coloured conjunctival masses in the context of acute mononucleosis and lymphoproliferative disorders. Moreover, EBV can cause haemorrhagic conjunctivitis and its corneal implications appear as different types of keratitis patterns. The involvement of EBV in the pathogenesis of anterior segment inflammation is not well-defined. Current evidence regarding anterior segment disease caused by EBV infection has been proved by positive viral detection through polymerase chain reaction test in eyes with lymphoproliferative disorders known to be caused by EBV, as B- and NK/T-cell lymphoid tumours. Antiviral treatment (oral Aciclovir or Valaciclovir) in anterior segment disease caused by EBV remains controversial.

ACUTE RETINAL NECROSIS: Difference in Outcome by Viral Type and Options for Antiviral Therapy

PURPOSE

To investigate differences in outcomes of acute retinal necrosis with confirmed viral polymerase chain reaction between viral types and highlight different treatment options.

METHODS

The study evaluated 22 eyes in 18 patients of polymerase chain reaction-positive acute retinal necrosis at the University of Pittsburgh Medical Center from 2007 to 2018. Outcome measures included final visual acuity, treatment paradigms, and retinal detachment rate.

RESULTS

Eight eyes were polymerase chain reaction-positive for varicella zoster virus, two eyes for herpes simplex virus Type 1 (HSV-1), and 12 eyes for herpes simplex virus Type 2 (HSV-2). Final Snellen best-corrected visual acuity averaged 20/51 for varicella zoster virus, 20/25 for HSV-1, and 20/814 for HSV-2. Retinal detachment occurred in 2 (25%) of varicella zoster virus eyes and 8 (75%) of HSV-2 eyes. One eye with HSV-1 and three eyes with HSV-2 received cidofovir for treatment of refractory retinitis.

CONCLUSION

Acute retinal necrosis secondary to HSV-2 tended to have persistent active retinitis with a higher rate of retinal detachment despite similar treatment protocols, suggesting that in some cases combination intravenous acyclovir and adjuvant intravitreal foscarnet injections are not sufficient. Despite the risk of renal toxicity, intravenous cidofovir may be a consideration in select patients.

Practical use of multiplex and broad-range PCR in ophthalmology

BACKGROUND

Polymerase chain reaction (PCR) can be used to confirm or deny infectious ocular inflammation such as uveitis. The purpose of this article is to review the current practical use of PCR examination in ophthalmology, especially multiplex and broad-range PCR, and a novel PCR, termed Strip PCR. At first, in the Introduction, we show the development of the PCR examination in ophthalmology. We next show the clinical applications of multiplex PCR and broad-range PCR. These advances in PCR continue to contribute greatly to the ophthalmology field. We also show how the sample for PCR is collected. Recently, we established a novel examination, a multiplex real-time PCR (Strip PCR) prototype for detecting 24 pathogens responsible for ocular infectious diseases. Moreover, we developed the Direct Strip PCR method, which skips the DNA extraction step in the procedure. This PCR is anticipated to ease etiologic evaluation, increasing pathogen detection in the intraocular fluids of uveitis patients even by general ophthalmologists. We also describe the following: (1) representative cases in which PCR is useful, (2) representative cases in which PCR can exclude a diagnosis, (3) the current status of PCR in the diagnosis of infectious uveitis and advanced medical service, and (4) the prospects for clinical PCR in ophthalmology.

CONCLUSION

We have established and developed the multiplex PCR, broad-range PCR, Strip PCR, and Direct Strip PCR methods and have reported the efficacy of such tests in multicenter studies. Our goal is "rapid and simple comprehensive PCR diagnosis anywhere and by anyone" for ocular infections.

In Vitro and In Vivo Activity, Tolerability, and Mechanism of Action of BX795 as an Antiviral against Herpes Simplex Virus 2 Genital Infection

Herpes simplex virus type 2 (HSV-2) causes recurrent lesions in the anogenital area that may be transmitted through sexual encounters. Nucleoside analogs, such as acyclovir (ACV), are currently prescribed clinically to curb this infection. However, in some cases, reduced efficacy has been observed due to the emergence of resistance against these drugs. In our previous study, we reported the discovery of a novel anti-HSV-1 small molecule, BX795, which was originally used as an inhibitor of TANK-binding kinase 1 (TBK1). In this study, we report the antiviral efficacy of BX795 on HSV-2 infection in vaginal epithelial cells in vitro at 10 μM and in vivo at 50 μM. Additionally, through biochemical assays in vitro and histopathology in vivo, we show the tolerability of BX795 in vaginal epithelial cells at concentrations as high as 80 μM. Our investigations also revealed that the mechanism of action of BX795 antiviral activity stems from the reduction of viral protein translation via inhibition of protein kinase B phosphorylation. Finally, using a murine model of vaginal infection, we show that topical therapy using 50 μM BX795 is well tolerated and efficacious in controlling HSV-2 replication.

Looking back to move forward: a twenty-year audit of herpes zoster in Asia-Pacific

Background

Herpes zoster (HZ) is a prevalent viral disease that inflicts substantial morbidity and associated healthcare and socioeconomic burdens. Current treatments are not fully effective, especially among the most vulnerable patients. Although widely recommended, vaccination against HZ is not routine; barriers in Asia-Pacific include long-standing neglect of adult immunisation and sparse local data. To address knowledge gaps, raise awareness, and disseminate best practice, we reviewed recent data and guidelines on HZ from the Asia-Pacific region.

Methods

We searched PubMed, Scopus, and World Health Organization databases for articles about HZ published from 1994 to 2014 by authors from Australia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, New Zealand, the Philippines, Singapore, Taiwan, Thailand, and Vietnam. We selected articles about epidemiology, burden, complications, comorbidities, management, prevention, and recommendations/guidelines. Internet searches retrieved additional HZ immunisation guidelines.

Results

From 4007 retrieved articles, we screened-out 1501 duplicates and excluded 1264 extraneous articles, leaving 1242 unique articles. We found guidelines on adult immunisation from Australia, India, Indonesia, Malaysia, New Zealand, the Philippines, South Korea, and Thailand.

HZ epidemiology in Asia-Pacific is similar to elsewhere; incidence rises with age and peaks at around 70 years – lifetime risk is approximately one-third. Average incidence of 3–10/1000 person-years is rising at around 5% per year. The principal risk factors are immunosenescence and immunosuppression. HZ almost always causes pain, and post-herpetic neuralgia is its most common complication. Half or more of hospitalised HZ patients have post-herpetic neuralgia, secondary infections, or inflammatory sequelae that are occasionally fatal. These disease burdens severely diminish patients’ quality of life and incur heavy healthcare utilisation.

Conclusions

Several countries have abundant data on HZ, but others, especially in South-East Asia, very few. However, Asia-Pacific countries generally lack data on HZ vaccine safety, efficacy and cost-effectiveness. Physicians treating HZ and its complications in Asia-Pacific face familiar challenges but, with a vast aged population, Asia bears a unique and growing burden of disease. Given the strong rationale for prevention, most adult immunisation guidelines include HZ vaccine, yet it remains underused. We urge all stakeholders to give higher priority to adult immunisation in general and HZ in particular.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2198-y) contains supplementary material, which is available to authorized users.

Diagnosis and Treatment of Acute Retinal Necrosis: A Report by the American Academy of Ophthalmology

PURPOSE

To evaluate the available evidence in peer-reviewed publications about the diagnosis and treatment of acute retinal necrosis (ARN).

METHODS

Literature searches of the PubMed and Cochrane Library databases were last conducted on July 27, 2016. The searches identified 216 unique citations, and 49 articles of possible clinical relevance were reviewed in full text. Of these 49 articles, 27 were deemed sufficiently relevant or of interest, and they were rated according to strength of evidence. An additional 6 articles were identified from the reference lists of these articles and included. All 33 studies were retrospective.

RESULTS

Polymerase chain reaction (PCR) testing of aqueous or vitreous humor was positive for herpes simplex virus (HSV) or varicella zoster virus (VZV) in 79% to 100% of cases of suspected ARN. Aqueous and vitreous specimens are both sensitive and specific. There is level II and III evidence supporting the use of intravenous and oral antiviral therapy for the treatment of ARN. Data suggest that equivalent plasma drug levels of acyclovir can be achieved after administration of oral valacyclovir or intravenous acyclovir. There is level II and III evidence suggesting that the combination of intravitreal foscarnet and systemic antiviral therapy may have greater therapeutic efficacy than systemic therapy alone. The effectiveness of prophylactic laser or early pars plana vitrectomy (PPV) in preventing retinal detachment (RD) remains unclear.

CONCLUSIONS

Polymerase chain reaction testing of ocular fluid is useful in supporting a clinical diagnosis of ARN, but treatment should not be delayed while awaiting PCR results. Initial oral or intravenous antiviral therapy is effective in treating ARN. The adjunctive use of intravitreal foscarnet may be more effective than systemic therapy alone. The role of prophylactic laser retinopexy or early PPV is unknown at this time.

Protection from lethal herpes simplex virus type 1 infection by vaccination with a UL41-deficient recombinant strain

The UL41 gene of herpes simplex virus type 1 (HSV-1) encodes a virion host shut off protein which is involved in immune evasion.　The growth and virulence of HSV-1 is markedly reduced by the deletion of UL41.　In this report, the UL41-deleted recombinant HSV-1 strain VR∆41 was evaluated as a prophylactic live attenuated vaccine against lethal HSV-1 infection in a mouse model.　Intraperitoneal (i.p.) inoculation with the VR∆41 strain clearly inhibited lethal wild-type HSV-1 (VR-3 strain) infection after both i.p. and intracerebral (i.c.) inoculations.　Vaccination with the VR∆41 strain was safer than VR-3 vaccination and was able to protect against a wild-type challenge to the same degree as VR-3 vaccination.　In contrast, i.p. inoculation with ultraviolet-irradiated VR-3 induced resistance against i.p. infection, but not against i.c.

INFECTION

Although replication of the VR∆41 strain in mice was greatly reduced compared to that of the VR-3 strain, VR∆41 strain maintained the ability to spread to the central nervous system (CNS) from a peripheral inoculation site. These results indicated that the VR∆41 strain evoked a potent immune reaction through viral protein expression within CNS without the induction of lethal encephalitis.　The entry of antigens into the CNS was essential for the establishment of protective immunity against the lethal HSV encephalitis.　We concluded that only a live attenuated vaccine is able to afford a prophylactic effect against CNS infection with HSV.　In order to fulfill this requirement, UL41-deleted viruses provide a strong candidate for use as a recombinant live vaccine.

Herpes simplex virus 2 infection: molecular association with HIV and novel microbicides to prevent disease

Infection with herpes simplex viruses is one of the most ancient diseases described to affect humans. Infection with these viruses produces vexing effects to the host, which frequently recur. Infection with herpes simplex viruses is lifelong, and currently there is no vaccine or drug to prevent or cure infection. Prevalence of herpes simplex virus 2 (HSV-2) infection varies significantly depending on the geographical region and nears 20% worldwide. Importantly, HSV-2 is the first cause of genital ulcers in the planet. HSV-2 affects approximately 500 million people around the globe and significantly increases the likelihood of acquiring the human immunodeficiency virus (HIV), as well as its shedding. Thus, controlling HSV-2 infection and spread is of public health concern. Here, we review the diseases produced by herpes simplex viruses, the factors that modulate HSV-2 infection, the relationship between HSV-2 and HIV and novel therapeutic and prophylactic microbicides/antivirals under development to prevent infection and pathological outcomes produced by this virus. We also review mutations associated with HSV-2 resistance to common antivirals.

Human anelloviruses: an update of molecular, epidemiological and clinical aspects

Human torque teno viruses (TTVs) are new, emerging infectious agents, recently assigned to the family Anelloviridae. The first representative of the genus, torque teno virus (TTV), was discovered in 1997, followed by torque teno mini virus (TTMV) in 2000, and torque teno midi virus (TTMDV) in 2007. These viruses are characterized by an extremely high prevalence, with relatively uniform distribution worldwide and a high level of genomic heterogeneity, as well as an apparent pan-tropism at the host level. Although these viruses have a very high prevalence in the general population across the globe, neither their interaction with their hosts nor their direct involvement in the etiology of specific diseases are fully understood. Since their discovery, human anelloviruses, and especially TTV, have been suggested to be associated with various diseases, such as hepatitis, respiratory diseases, cancer, hematological and autoimmune disorders, with few arguments for their direct involvement. Recent studies have started to reveal interactions between TTVs and the host's immune system, leading to new hypotheses for potential pathological mechanisms of these viruses. In this review article, we discuss the most important aspects and current status of human TTVs in order to guide future studies.

Acute retinal necrosis (ARN) in the context of neonatal HSV-2 exposure and subconjunctival dexamethasone: case report and literature review

HSV-2 is an important cause of the acute retinal necrosis (ARN) syndrome in younger patients. We describe an atypical case of HSV-2 ARN in the context of neonatal exposure and subconjunctival steroid injection. Clinicians should be aware of the association of neonatal or congenital exposure to HSV-2 as a risk factor for this disease because early treatment may improve outcome and/or avoid involvement of both eyes.

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.

[Acute retinal necrosis from the virologist's perspective]

Acute retinal necrosis occurs in approximately one per million persons per year and is caused in approximately 70% of the cases by the varicella zoster virus or in about 30% of the cases by herpes simplex virus. The early diagnosis is primarily based on virus-specific polymerase chain reaction in fluid from the anterior chamber or vitreous humor and can be supported by the determination of specific antibody titers from fluid and serum. Virus detection provides the basis for early causative therapy which limits disease progression and risk of complications. Retinal infections by varicella zoster virus or herpes simplex virus are treated with aciclovir, ganciclovir, or famciclovir. Ganciclovir and valganciclovir are used for the therapy of retinal cytomegalovirus infections. In the case of resistance development, foscarnet or cidofovir are available as second line antiviral drugs. The early use of specific antiviral agents is a crucial prerequisite for optimized therapy of acute retinal necrosis.

17-beta estradiol promotion of herpes simplex virus type 1 reactivation is estrogen receptor dependent

Correlations between estrogen and herpes simplex virus (HSV) reactivation from latency have been suggested by numerous clinical reports, but causal associations are not well delineated. In a murine HSV-1 corneal infection model, we establish 17-beta estradiol (17-betaE) treatment of latently infected ovariectomized mice induces viral reactivation, as demonstrated by increased viral load and increased immediate-early viral gene expression in the latently infected trigeminal ganglia (TG). Interestingly, the increased HSV reactivation occurred in the absence of inhibition of viral specific CD8(+) T-cell effector function. 17-betaE administration increased HSV reactivation in CD45(+) cell-depleted TG explant cultures, providing further support that leukocyte-independent effects on latently infected neurons were responsible for the increased reactivation. The drug-induced increases in HSV copy number were not recapitulated upon in vivo treatment of latently infected estrogen receptor alpha-deficient mice, evidence that HSV reactivation promoted by 17-betaE was estrogen receptor dependent. These findings provide additional framework for the emerging conceptualization of HSV latency as a dynamic process maintained by complex interactions among multiple cooperative and competing host, viral, and environmental forces. Additional research is needed to confirm whether pregnancy or hormonal contraceptives containing 17-betaE also promote HSV reactivation from latency in an estrogen receptor-dependent manner.

Acute retinal necrosis caused by herpes simplex virus type 2 in a 3-year-old Japanese boy

Acute retinal necrosis (ARN), which is characterized by rapidly progressing peripheral retinal necrosis, is caused mainly by herpes simplex virus type 1, herpes simplex virus type 2 (HSV-2), or varicella-zoster virus. A previously healthy 3-year-old Japanese boy developed ARN in his left eye after being bruised by a milk container. HSV-2 DNA was detected in the aqueous humor of the affected eye. Serological testing suggested that the route of infection was from mother to child, although there was no past history of apparent HSV-2 infection. Childhood ARN has not been previously reported in Japan, possibly because of the low seroprevalence of HSV-2 in Japanese women. Pediatricians must be aware of this rare disease, which can affect individuals without a previous history of HSV even in a country with a low seroprevalence of HSV-2.

Medroxyprogesterone acetate inhibits CD8+ T cell viral-specific effector function and induces herpes simplex virus type 1 reactivation

Clinical research suggests hormonal contraceptive use is associated with increased frequencies of HSV reactivation and shedding. We examined the effects of medroxyprogesterone acetate (MPA), the compound most commonly used for injectable hormonal contraception, on HSV type 1 (HSV-1) reactivation and CD8(+) T cell function in murine trigeminal ganglia (TG). In ex vivo TG cultures, MPA dramatically inhibited canonical CD8(+) T cell effector functions, including IFN-gamma production and lytic granule release, and increased HSV-1 reactivation from latency. In vivo, MPA treatment of latently infected ovariectomized mice inhibited IFN-gamma production and lytic granule release by TG resident CD8(+) T cells stimulated directly ex vivo. RNA specific for the essential immediate early viral gene ICP4 as well as viral genome DNA copy number were increased in mice that received MPA during latency, suggesting that treatment increased in vivo reactivation. The increase in HSV-1 copy number appeared to be the result of a two-tine effect, as MPA induced higher reactivation frequencies from latently infected explanted TG neurons in the presence or absence of CD45(+) cells. Our data suggest hormonal contraceptives that contain MPA may promote increased frequency of HSV reactivation from latency through the combinatory effects of inhibiting protective CD8(+) T cell responses and by a leukocyte-independent effect on infected neurons.

Evaluation of mixed infection cases with both herpes simplex virus types 1 and 2

Herpes simplex virus type 1 (HSV-1) is isolated principally from the upper half of the body innervated by the trigeminal ganglia whereas herpes simplex virus type 2 (HSV-2) is generally isolated from the lower half of the body innervated by the sacral ganglia. However, recent reports suggest that HSV-1 and HSV-2 can each infect both the upper and lower half of the body causing a variety of symptoms and there is a possibility that HSV-1 and HSV-2 infections can occur simultaneously with both causing symptoms. HSV type in clinical isolates from 87 patients with genital herpes and 57 with ocular herpes was determined by the polymerase chain reaction (PCR), and six cases of mixed infection with both HSV-1 and HSV-2 were identified. Of the six cases, three were patients with genital herpes and three were ocular herpes patients. Analysis of the copy number of the HSV-1 and HSV-2 genome by a quantitative real time PCR demonstrated that HSV-1 was dominant at a ratio of approximately 100:1 in the ocular infections. In contrast, the HSV-2 genome was present at a 4-40 times higher frequency in isolates from genital herpes patients. There was no obvious difference between the clinical course of mixed infection and those of single HSV-1 or HSV-2 infections. This study indicated that the frequency of mixed infection with both HSV-1 and HSV-2 is comparatively higher than those of previous reports. The genome ratio of HSV-1 and HSV-2 reflects the preference of each HSV type for the target organ.

Acute retinal necrosis: a national population-based study to assess the incidence, methods of diagnosis, treatment strategies and outcomes in the UK

AIM

To determine the incidence, methods of diagnosis, treatment strategies and outcomes for acute retinal necrosis (ARN) in the UK.

METHODS

A 12-month active case ascertainment study was carried out between March 2001 and March 2002 to record cases of ARN presenting to ophthalmologists via the British Ophthalmological Surveillance Unit (BOSU) reporting system. Questionnaires were sent to the reporting consultants, requesting data on patient characteristics, presentation, clinical findings, investigations and treatment. Diagnosis was made using the American Uveitis Society diagnostic criteria. Further questionnaires were sent at 2 weeks and 6 months to assess outcome and therapies.

RESULTS

74 cases of ARN were reported by 58 consultants between March 2001 and March 2002. Questionnaires were returned for 49 cases (66.2%), of which 18 (36.7%) were excluded. Of the 31 cases included, 22 (71.0%) were male and 9 (29.0%) were female. The age range was 13 to 85 years (mean 54.3 years). 28 cases (90.3%) were unilateral, with 3 patients (9.7%) presenting with bilateral ARN. An aqueous or vitreous biopsy was performed in only 18 patients, with one patient having both. Herpes viral DNA analysis was performed on all 19 biopsies, with identification of the viral DNA in 16; results from 3 biopsies were not documented. Varicella zoster virus (VZV) was the commonest cause identified in 10 patients (56%). Of the 31 subjects, 27 (87.1%) were treated for ARN with systemic antiviral treatment: with intravenous antiviral in 23 cases (85.2%) and oral antiviral in 4 cases (14.8%). 21 of these patients went on to receive oral antiviral maintenance therapy. In addition to antiviral treatment, systemic steroids were given to 16 subjects (51.6%). Surgical intervention for retinal detachment was performed on 5 patients.

CONCLUSIONS

During the 12-month study period, 31 cases of ARN met the diagnostic criteria set by the American Uveitis Society. The incidence in the UK based on this study is approximately 1 case per 1.6 to 2.0 million population per year. We have ascertained that the management of ARN throughout the UK is variable, suggesting that national guidelines would be of benefit.

Diagnostic testing of vitrectomy specimens

PURPOSE

To assess the usefulness of diagnostic tests that are performed on vitrectomy specimens from patients with suspected lymphoma or infection.

DESIGN

Noncomparative, retrospective, interventional case series.

METHODS

Seventy-eight consecutive patients (84 eyes) underwent pars plana vitrectomy for diagnostic purposes. Vitrectomy with cytologic, cytofluorographic, or microbiologic analysis of vitreous samples was performed. The main outcome measures were the efficiency of diagnostic procedure and positive and negative predictive values (PPV and NPV).

RESULTS

There were 28 patients (33 eyes) with suspected intraocular lymphoma and 50 patients (51 eyes) with suspected infection, which was subdivided into chronic endogenous endophthalmitis, atypical chorioretinitis, or chronic postoperative inflammation. Vitreous testing led to a diagnosis in 48 of 78 patients (61.5%); 14 patients with a final diagnosis of lymphoma/leukemia, and 34 patients with a final diagnosis of infection. When preoperative indication was compared with final clinical diagnosis, the efficiency of the diagnostic procedure of cytologic evaluation, flow cytometry, and bacterial/fungal culture was 67%, 79%, and 96%, respectively. For lymphoma, the PPV of cytologic evaluation was 100% and the NPV 60.9%. For infection, the PPV of bacterial/fungal culture was 100% and the NPV 94.9%. CD22+ B lymphocytes >or=20% of total cells on cytofluorographic analysis had a PPV of 88% for lymphoma. A cytofluorographic CD4:CD8 T-lymphocyte ratio >or=4 had a PPV of 70% for immunologically mediated uveitis. Surgical complications were rare and manageable.

CONCLUSION

Diagnostic vitrectomy in selected patients with carefully planned testing is an effective means of supporting diagnoses in intraocular lymphoma, chronic intraocular infections, and atypical chorioretinitis. Flow cytometry quantitates the percentages and ratios of various cell types and is helpful in contrasting intraocular lymphoma with immunologically mediated uveitis.

Herpes simplex virus type 2 acute retinal necrosis 9 years after neonatal herpes

Many cases of acute retinal necrosis caused by HSV-2 have been reported in children, teenagers, and young adults as a result of reactivation of congenital or neonatal infections, which may have been subclinical. Pediatricians should be aware of this entity and alert to recurrences that may be delayed by years.

Necrotising retinopathies simulating acute retinal necrosis syndrome

AIM

To determine an aetiological diagnosis in patients presenting with necrotising retinopathies that simulate acute retinal necrosis (ARN).

METHODS

Retrospective non-comparative case series. The charts of 16 patients presenting with a clinical impression of ARN at Pitie-Salpetriere Hospital, Paris, France, between 1994 and 1999, who required initial antiviral therapy were reviewed. All of the patients had extensive laboratory tests. Anterior chamber paracentesis was performed on 14 patients and evaluated by polymerase chain reaction (PCR) and/or the Witmer-Goldmann coefficient to determine the cause of retinitis. Three of the 14 cases also had diagnostic vitrectomy. Responses to specific treatment, initiated based on laboratory results, and the final outcome were evaluated.

RESULTS

Seven of the 16 patients were female and nine were male. The retinitis was bilateral in five patients and unilateral in 11 patients. The average age of the patients at presentation was 53.6 years. 13 patients were immune deficient for various reasons. Upon initial presentation, the patients' visual acuities were less than 20/200 in 68% of the affected eyes. The final diagnoses, based on laboratory data and therapeutic response were toxoplasmic retinochoroiditis (62.5%), syphilitic retinitis (12.5%), aspergillus endophthalmitis (12.5%), Behcet's disease (6.2%), and intraocular lymphoma (6.2%). Visual acuity was stabilised or improved in 12 patients (75%). Two patients with aspergillosis died despite antifungal therapy.

CONCLUSIONS

Toxoplasmic retinochoroiditis is the major cause of retinal necrosis that simulates ARN, and PCR analysis of the aqueous humour is helpful in establishing the diagnosis. Such atypical toxoplasma retinochoroiditis may be associated with poor visual outcome.

Nécrose rétinienne aiguë bilatérale associée à une méningo-encéphalite à Herpes simplex virus 2

INTRODUCTION

Acute retinal necrosis syndrome (ARN syndrome) is a rare viral disease with a poor prognosis in most cases. It is characterized by substantial ocular inflammation with progressive retinal necrosis, occlusive vasculitis and sometimes extraocular features.

CASE REPORT

We report the case of a 62-year-old woman who was referred for a suspicion of a stroke. Ophthalmological examination revealed a profound bilateral visual loss due to extensive retinal necrosis. The patient was immediately treated with antiherpetic drugs. ARN syndrome with meningoencephalitis caused by herpes simplex virus type 2 was confirmed by PCR studies performed on aqueous humor and cerebrospinal fluid. Herpes simplex virus 2 (IgG+ , IgM-) was probably reactivated after intrathecal injection of steroids because of pain associated with narrowing of the lumbar vertebral canal. The patient was treated with intravenous Acyclovir for 3 weeks. After 4 months, both retinas were detached.

DISCUSSION AND CONCLUSION

ARN syndrome caused by herpes simplex virus 2 most often occurs after reactivation of the latent virus in patients with a neurological medical history or congenital infection. Antiviral treatment must begin early to decrease risks of bilateralization and complications.

Rétinites nécrosantes herpétiques

The diagnosis of necrotic herpetic retinitis is suggested on clinical grounds, prompting urgent appropriate intravenous and intravitreal treatment. PCR on ocular samples is most often successful in identifying the herpetic agent. Classic acute retinal necrosis syndrome caused by herpes simplex or zoster virus and the different clinical forms present in immunocompetent or immunodepressed patients are described. The differential diagnosis includes atypical presentation of retinal necrosis caused by toxoplasmosis, syphilis, or ocular lymphoma; the ocular samples are useful in establishing the etiological diagnosis. We describe the different therapeutic strategies in the acute phase and as secondary prophylactic treatment. The clinical outcome appears to be influenced by rapid, appropriate treatment, limiting the extension of the retinal necrosis.

Clinical characteristics of acute HSV-2 retinal necrosis

PURPOSE

To report the clinical features and evaluate the visual outcome of eleven cases of herpes simplex virus-2 (HSV-2) related acute retinal necrosis syndrome (ARN).

DESIGN

Retrospective interventional case series.

METHODS

Twelve eyes of eleven patients from two European centers, diagnosed with HSV-2 related acute retinal necrosis syndrome were retrospectively reviewed. Herpes simplex virus-2 DNA was detected by polymerase chain reaction in intraocular fluids (aqueous and/or vitreous). Findings at initial examination, clinical evolution with antiviral therapy, complications and final visual acuity were evaluated.

RESULTS

Herpes simplex virus-2 DNA was detected in all cases. No sample was positive for more than one virus. The mean age of disease in the first eye was 36 years (ranged from 10 to 57 years). Five patients were women and six were men. All patients were immunocompetent. Previous medical history included neonatal herpes (n = 1), previous ARN (n = 3), trauma (n = 1) and systemic corticosteroid administration before occurrence of ARN (n = 3). Preexisting pigmented chorioretinal scars were found in three cases. Patients were treated with high dose intravenous acyclovir or foscarnet +/- intravitreal ganciclovir +/- interferon. The mean follow-up was 14.5 months (from 5 to 22 months). At the end of the follow-up period, five eyes (41.7%) showed improvement of visual acuity of two or more lines. Final visual acuity was 20/60 or better in four eyes (33.3%), 20/400 or better in four eyes (33.3%) and less than 20/400 in four eyes.

CONCLUSION

History of neonatal herpes, triggering events such as neurosurgery, periocular trauma, high-dose corticosteroids, and chorioretinal scars suggest that HSV-2 retinitis reflects reactivation of HSV-2 infection.

Prise en charge diagnostique et thérapeutique des rétinites nécrosantes herpétiques

PURPOSE

To study the viral cause and present the management of necrotizing herpetic retinopathies.

METHODS

Charts of patients presenting with acute retinal necrosis (ARN) or progressive outer retinal necrosis (PORN) diagnosed between March 1997 and June 2001 were retrospectively reviewed. Intraocular specimens were obtained in 33 cases to determine the viral cause using polymerase chain reaction-based assays and/or detection of intraocular antibody production.

RESULTS

The mean age was 43.4 Years. Herpesvirus genome was identified in 29 patients (80.5%). In the ARN group (32 patients, 38 eyes), herpes simplex virus (HSV) DNA was found in 11 patients (34.4%), varicella-zoster virus (VZV) in nine patients (28.1%), and cytomegalovirus (CMV) in four patients (12.5%). One patient (3.1%) presented an Epstein-Barr virus (EBV) infection. ARN was bilateral at initial examination in six patients and secondary bilateralization was observed in four patients. In the PORN group (four patients, eight eyes), the retinitis was bilateral and VZV DNA was detected in all cases. Two patients were treated with intravenous acyclovir, six with foscarnet alone, ten with intravenous foscarnet + acyclovir, 18 with intravenous foscarnet and intravitreous ganciclovir injections. Complications of necrotizing herpetic retinitis were cataract (26%), optic nerve atrophy (23.9%), and retinal detachment (17.4%). Final visual acuity was less or equal to 20/200 in 47.8% of cases.

CONCLUSIONS

It is important to determine the specific viral etiology since progression and prognosis may be different in herpetic necrotizing retinitis caused by HSV, VZV, or CMV. Visual prognosis is improved by intensive antiviral therapy, but remains poor if complications occur.

Nonnecrotizing herpetic retinopathies masquerading as severe posterior uveitis

OBJECTIVE

Aqueous humor analysis can be performed in severe atypical forms of posterior uveitis unresponsive to conventional treatment to exclude a viral infection.

DESIGN

Noncomparative interventional case series.

PARTICIPANTS

Thirty-seven immunocompetent patients seen with corticosteroid-resistant forms of posterior uveitis underwent extensive evaluation, including anterior chamber paracentesis, to rule out a nonnecrotizing viral retinopathy.

INTERVENTION

Aqueous fluid samples were prospectively obtained. Polymerase chain reaction (PCR) and serologic evaluation of intraocular antibody production against herpesviruses were performed by molecular techniques and enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURES

Polymerase chain reaction and local antibody production for herpes simplex virus types 1 and 2, varicella-zoster virus, cytomegalovirus, and Epstein-Barr virus were determined on aqueous fluid samples.

RESULTS

Viral infection was confirmed in 5 cases (13.5%). Clinical presentation included birdshot-like retinochoroidopathy, occlusive bilateral vasculitis, and cystoid macular edema. An antiviral regimen was initiated in all cases. Inflammation was stabilized, and steroid dosage could be significantly reduced.

CONCLUSIONS

Identification of a viral agent during severe posterior uveitis can dramatically change therapeutic management.

Polymerase chain reaction as a rapid diagnostic tool for therapy of acute retinal necrosis syndrome

Herpesviruses are involved in the pathogenesis of acute retinal necrosis syndrome (ARN). A rapid and accurate diagnosis of herpetic infections is crucial for prompt administration of a specific antiviral therapy. The purpose of this study was to evaluate a polymerase chain reaction (PCR)-based assay to detect herpesvirus DNA in the aqueous humor of clinical samples from ten patients with uveitis and clinical suspicion of ARN. Samples were assayed for herpes simplex virus type 1-2 (HSV 1-2), varicella zoster virus (VZV) and cytomegalovirus (CMV). Clinical suspicion of ARN was confirmed for four patients. Two patients (one with bilateral ARN) tested PCR-positive for VZV DNA and the other two were positive for HSV 1-2 DNA. CMV DNA was not detected in any of the samples, and no sample was positive for DNA from more than one virus. The remaining patients did not show any evidence of herpesvirus DNA in their aqueous samples. Our findings demonstrate that the use of PCR for detecting herpesvirus DNA in aqueous humor of uveitic subjects may be a valuable tool for early diagnosis of acute retinal necrosis syndrome and for timely administration of a suitable therapy.

Polymerase chain reaction analysis of aqueous humour samples in necrotising retinitis

AIM

To evaluate the diagnostic value of polymerase chain reaction (PCR) performed on aqueous humour for the detection of viral DNA in patients with necrotising herpetic retinitis.

METHODS

The clinical features and laboratory results of 22 patients (29 eyes) presenting with necrotising herpetic retinitis between March 1999 and June 2001 were reviewed retrospectively. Aqueous humour was obtained after anterior chamber paracentesis and PCR was performed in all cases.

RESULTS

Viral DNA was detected in the aqueous humour of 19 patients (86.4%). Epstein-Barr virus (EBV) seroconversion was evidenced in one additional patient. In the acute retinal necrosis (ARN) group (n = 19), varicella zoster virus (VZV) DNA was identified in six patients, herpes simplex virus 1 (HSV-1) DNA in two patients, herpes simplex virus 2 (HSV-2) DNA in four patients, and cytomegalovirus (CMV) genome in four patients. In the progressive outer retinal necrosis (PORN) group (n = 3), VZV DNA was detected in all patients. No sample was positive for more than one virus.

CONCLUSIONS

PCR analysis of aqueous humour in patients with clinical features of necrotising viral retinitis can provide specific aetiological orientation and the method appears to be safe and highly sensitive.

Herpes simplex virus type 2 acute retinal necrosis in an immunocompetent patient

PURPOSE

To report a case of acute retinal necrosis caused by herpes simplex virus 2 in an otherwise healthy patient.

CASE REPORT

A 45-year-old man presented with one month's history of decreased vision in the right eye. He had previously received a course of intravenous gancyclovir because of a clinical suspicion of cytomegalovirus retinitis. The patient's ocular history was remarkable for a similar episode in the left eye thirty years earlier, resulting in important visual impairment. System and laboratory investigations were unremarkable. Ocular examination showed severe anterior granulomatous uveitis, vitreous haze, areas of necrosis and retinal exudates. The anterior chamber tap disclosed the presence of HSV type 2, and oral steroids and acyclovir were instituted. Two weeks after the patient had been discharged, a retinal detachment occurred in the right eye, necessitating surgical repair. The presence of HSV type 2 was confirmed in the vitreous. Visual acuity recovered completely after surgery and the patient was placed on a maintenance dose of oral acyclovir.

CONCLUSIONS

HSV type 2 is a rare cause of acute retinal necrosis in healthy patients. Bilateral involvement can occur in the fellow eye, even with a long delay. Acute retinal necrosis is a severe ocular inflammatory syndrome associated with a very poor visual outcome. It is caused by VZV, HSV type 1 and, less commonly, by HSV type 2. The disease can affect healthy patients and cause bilateral involvement in the fellow eye, even with a long delay.

Viral causes of the acute retinal necrosis syndrome

Acute retinal necrosis has been described as a clinical entity for nearly 30 years. Acute retinal necrosis is a potentially visually devastating necrotizing vaso-occlusive retinitis affecting both healthy and immunocompromised patients. Acute retinal necrosis is caused by the herpes group of viruses, mainly varicella zoster, herpes simplex types 1 and 2, and, rarely, cytomegalovirus. Recently, polymerase chain reaction techniques have enabled detection of very small amounts of viral DNA from intra-ocular fluid samples. This can help in both the diagnosis of atypical cases of retinitis and uveitis and directing treatment in cases of acute retinal necrosis.

Herpes simplex virus epidemiology and ocular importance

PURPOSE

To review the changing epidemiology of herpes simplex disease and correlate it with the epidemiology of ocular herpes simplex disease.

METHOD

A review of pertinent reports in the world literature about the epidemiology of herpes simplex and specifically about ocular herpes simplex.

RESULTS

In developed countries, many individuals are reaching adolescence and adulthood without prior herpesvirus infection. Herpes simplex genital infection is increasing at a rapid rate in sexually active adolescents and adults, with about one in six adults now infected in the United States. Similar statistics are confirmatory worldwide in developed countries. Active herpes simplex infection is a risk factor for acquisition of human immunodeficiency virus. The Herpetic Eye Disease Study, as well as prior studies from Moorfields Eye Hospital and the Mayo Clinic in Rochester, Minnesota, provides us with the epidemiology of ocular herpes simplex. Recent studies suggest an older age of onset and perhaps overall more severe ocular disease as compared with the older literature.

CONCLUSIONS

Herpes simplex is a significant health concern at present with genital infections increasing in epidemic proportions. This is also reflected in a rise in the incidence of neonatal herpes. Herpes simplex virus type 1 (HSV-1) infection is being acquired for the first time in an older age group. A significant and increasing proportion of genital herpes is caused by HSV-1. Serologic studies are no longer as useful in distinguishing orofacial herpes from genital herpes. More acute retinal necrosis syndrome cases are associated with HSV-2. Speculation about the future of ocular herpes is made based on this changing epidemiology.