Acute retinal necrosis syndrome

Clinical Insights: Antimicrobial Therapy for Infectious Uveitis

Infectious uveitis is a major global cause of vision impairment. Despite the eye's immune privilege, afforded by the blood-ocular barrier that restricts microbial entry, several pathogens such as bacteria, viruses, fungi, and parasites can still infiltrate and cause ocular infections and complications. Clinicians often encounter significant challenges in treating infectious uveitis due to limited or ineffective treatment options. Modern molecular techniques and imaging can aid in diagnosing and assessing intraocular infections. Various antimicrobial therapies exist, spanning topical and systemic treatments, but these are constrained by issues like drug concentration, penetration, effective duration, toxicity, and side effects. Treatment approaches also differ based on the infection's etiology. This review provides recent updates on antimicrobial therapies from a clinical perspective, covering topical, systemic, and regional treatments for infectious uveitis.

RETINAL DETACHMENT AFTER ACUTE RETINAL NECROSIS AND THE EFFICACIES OF DIFFERENT INTERVENTIONS: A Systematic Review and Metaanalysis

PURPOSE

To estimate the rate of retinal detachment (RD) after acute retinal necrosis (ARN) and evaluate the efficacies of different interventions.

METHODS

The databases Medline and EMBASE from inception to March 2020 were searched to identify the relevant studies. R software version 3.6.3 was used to perform the statistical analyses. Results in proportion with 95% confidence interval were calculated using generalized linear mixed models.

RESULTS

Sixty-seven studies involving 1,811 patients were finally included. The pooling results suggested the general RD rate of ARN was 47%. The RD rate increased with the extent of retinitis and was slightly lower when involved Zone III. The RD rate was 37% for herpes simplex virus ARN and 46% for varicella-zoster virus ARN; 52% for immunocompetent patients and 39% for immunocompromised patients. Retinal detachment presented in 2% of eyes at the first visit. Systemic antiviral therapy could lower the RD rate significantly from 67% to 43%, and prophylactic vitrectomy could lower the RD rate significantly from 45% to 22%. Systemic antiviral therapy plus vitrectomy achieved the lowest RD rate to 18%. Although the efficacy of prophylactic laser or intravitreal antiviral therapy was still limited. Prophylactic vitrectomy might significantly increase the incidence of proliferative vitreoretinopathy from 7% to 32%.

CONCLUSION

About half of the eyes might develop RD during the entire course of ARN. Systemic antiviral therapy and prophylactic vitrectomy are effective interventions to prevent RD, whereas the roles of prophylactic laser or adjunctive intravitreal antiviral therapy are still unclear. Varicella-zoster virus ARN and cases with extensive retinitis might need intensified interventions.

Acute Retinal Necrosis Presenting as Central Retinal Artery Occlusion with Cilioretinal Sparing

Purpose

To report a case of acute retinal necrosis presenting as central retinal artery occlusion with cilioretinal sparing.

Methods

Single inter ventional case report. The findings of the ophthalmic examination, MRI, blood parameters, biopsy results and clinical course are reported.

Results

A forty two year old gentleman reporting sudden loss of sight, ophthalmic examination revealing uveitis, central retinal artery occlusion with cilioretinal sparing and peripheral necrotizing retinitis.

Conclusions

Central retinal artery occlusion can be an early feature of acute retinal necrosis (ARN).

Efficacy of Oral Valacyclovir Treatment in a Case with Acute Retinal Necrosis

Acute retinal necrosis (ARN) is a rapidly progressive disease with poor prognosis, leading to visual loss in most cases. Rapid diagnosis and early anti-viral treatment significantly affect the course and prognosis of the disease. In this case report, we present a 34-year-old female patient referred to our clinic with symptoms of blurred vision and ocular pain diagnosed as acute glaucoma elsewhere. A clinical diagnosis of ARN was made and anti-viral treatment was started immediately. We herein describe our treatment approach to this particular case and discuss previously reported treatment modalities.

Delayed recurrence of acute retinal necrosis (ARN): A case series

PURPOSE

To report five cases of acute retinal necrosis (ARN) that reactivated in the same eye or presented in the contralateral eye between two and nineteen years after the initial episode of acute retinal necrosis.

CASES

Five patients with a previous history of ARN developed recurrent ARN infection following a lengthy latency period. In all five patients who initially presented with unilateral disease, four developed infection in the contralateral eye and one developed recurrent infection in the ipsilateral eye. Latency periods ranged from two to nineteen years, and final visual acuity in the affected eyes ranged from 20/30 to no light perception. Each patient was treated with antiviral medication for both the initial infection and for subsequent reactivations, but was not on long-term prophylaxis at the time of recurrent disease.

CONCLUSION

Although rare, delayed onset reactivation of ARN can occur in either the same eye or contralateral eye despite adequate treatment. While contralateral spread of initial infection is fairly common, these reactivations rarely occur more than six weeks after initial infection. Currently there are no guidelines for use of prophylactic antiviral medication to prevent late recurrence of ARN.

Viral encephalitis complicated by acute retinal necrosis syndrome: A case report

Acute retinal necrosis syndrome (ARN) is a viral infection characterized by focal retinal necrosis. Viral meningitis complicated by ARN is relatively rare. In the present case study, a 44-year-old male presented with fever, headache and mental disorder. After four days, the patient developed blurred vision. The patient was diagnosed with viral encephalitis complicated by bilateral ARN, based on the examination results. After treatment with antivirals and systemic glucocorticoids, the symptoms of the patient improved. Viral encephalitis may be an important risk factor for ARN. For a patient with viral encephalitis who experiences decreased visual acuity or vitreous opacification, the possibility of ARN should be considered.

Bilateral acute retinal necrosis associated with neuroinfection in patient after renal transplantation

Background

Acute retinal necrosis (ARN) is characterized by the triad of acute vitritis, peripheral necrotizing retinitis and vasculitis.

Case Report

We report a case of 54-year-old woman with bilateral acute retinal necrosis associated with neuroinfection. Her past medical history included renal transplantation, hypertension and aortic stenosis. Observational case report: Diagnostic investigations included biochemical tests, lumbar puncture, eye ultrasonography and MRI of the brain.

Anti-HSV IgG antibody titers were elevated in the blood and cerebrospinal fluid. In MRI T2-mode, inflammatory changes were found in the white matter of the right hemisphere. The patient was treated with systemic acyclovir, itraconazole, metronidazole and ciprofloxacin for 3 weeks. Retinal detachment was observed in both eyes.

Conclusions

Acute retinal necrosis can be the single manifestation of herpes virus reactivation in patients after organ transplantation.

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.

Varicella-zoster virus: atypical presentations and unusual complications

Varicella-zoster virus (VZV) is the etiologic agent of varicella (primary infection) and herpes zoster (reactivation of latent infection). Although varicella is most often a relatively benign and self-limited childhood illness, the disease can be associated with a variety of serious and potentially lethal complications in both immunocompetent and immunocompromised persons. One complication of varicella that appears to be increasing in frequency is serious bacterial soft tissue infections caused by group A streptococci. Issues related to management of varicella become especially complex when varicella involves pregnant women or susceptible neonates. Herpes zoster can be associated with a variety of neurologic complications, including a syndrome of delayed contralateral hemiparesis. Neurologic complications of herpes zoster, including chronic encephalitis, occur with increased frequency in AIDS patients. VZV retinitis is a potentially sight-threatening complication that occurs in both immunocompetent and immunocompromised persons. Current knowledge regarding pathogenesis and antiviral therapy is reviewed.

Acute retinal necrosis syndrome in a child

We recently cared for an 11-year-old child with acute retinal necrosis syndrome, an ophthalmologic condition characterized by the triad of anterior uveitis, occlusive retinal vasculitis and progressive peripheral retinal necrosis. Acute retinal necrosis syndrome occurs primarily in nonimmunocompromised adults as a result of reactivated herpes simplex or varicella-zoster virus infection. Antiviral and antiinflammatory therapy appears to reduce the incidence of vision-threatening retinal necrosis and involvement of the contralateral eye.

Acute visual disturbance in a young adult

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Detecting herpesvirus DNA in uveitis using the polymerase chain reaction

BACKGROUND

Herpesviruses are involved in the pathogenesis of many ocular diseases including keratitis, iridocyclitis, and acute retinal necrosis syndrome. The rapid and accurate diagnosis of herpetic infections has become increasingly important with the rising incidence of immunosuppressive diseases. The purpose of this study was to evaluate the use of the polymerase chain reaction (PCR) to detect herpesvirus DNA in uveitis patients.

METHODS

Aqueous samples were aspirated from 11 patients with active uveitis of suspected viral origin. Using PCR, masked samples were assayed for herpes simplex virus (HSV), varicella zoster virus (VZV), and cytomegalovirus (CMV) to assist in supporting the clinical diagnosis of viral aetiology. Masked controls included 10 aqueous humour specimens from normal patients undergoing cataract surgery and specimens from seven patients diagnosed with active non-viral uveitis--Behçet's disease, sarcoidosis, Fuchs' heterochromic iridocyclitis, or Harada's disease.

RESULTS

Ten of 11 cases clinically diagnosed as being of possible viral aetiology yielded aqueous PCR positive for a herpesvirus. Eight patients were PCR positive for amplified HSV DNA, of whom two had acute retinal necrosis, one had corneal endotheliitis, and five had recurrent iridocyclitis. VZV DNA was detected in one case of iridocyclitis, and CMV DNA in one case of chorioretinitis. Successful therapy was based on the PCR results. Ten normal aqueous specimens and the seven uveitis samples from cases not suspected of a viral aetiology were PCR negative for HSV, VZV, and CMV.

CONCLUSION

These results demonstrate that detecting herpesvirus DNA in the aqueous humour is useful to support a clinical diagnosis of viral uveitis.

Herpes zoster chorioretinopathy

Chorioretinitis and subsequent choroidal and retinal pigment epithelial atrophy following herpes zoster ophthalmicus (HZO) have rarely been reported. We report two patients, who several months following attacks of acute HZO, developed posterior fundus features of yellow, non-pigmented, punched-out areas of retinal pigment epithelial and choroidal pigment atrophy, which we have termed herpes zoster chorioretinopathy. An occlusive vasculitic process is proposed as the pathogenesis for this chorioretinopathy, and may be similar to that seen in the delayed cerebral vasculitis following HZO. A previous history of HZO should be sought in patients with a unilateral, multifocal, non-pigmented chorioretinopathy, as this may represent a characteristic delayed feature.

Ectopic expression of gamma interferon in the eye protects transgenic mice from intraocular herpes simplex virus type 1 infections

Transgenic (rho gamma) mice provide a model for studying the influence of gamma interferon (IFN-gamma) produced in the eye on ocular and cerebral viral infection. To establish this model, we injected BALB/c- and C57BL/6-derived transgenic and nontransgenic mice of different ages intravitreally with herpes simplex virus type 1 (HSV-1) strain F. Eye and brain tissues of these mice were assessed for pathological and immunocytochemical changes. HSV-1 infection induced severe retinitis of the injected eyes and infection of the brain in all mice. In transgenic mice inoculated with HSV-1, the left, nontreated eyes were protected from retinitis, whereas nontransgenic mice developed bilateral retinitis. Additional intravitreal injection of IFN-gamma with the virus protected the noninoculated eyes of nontransgenic mice. Three-week-old nontransgenic mice died from HSV-1 infection, whereas transgenic mice of the same age and nontransgenic mice intravitreally treated with IFN-gamma survived. Ocular IFN-gamma production increased the extent of inflammation in transgenic mice but did not have a significant influence on the growth of HSV-1 until day 3 after inoculation and did not influence the neuroinvasion of this virus. Thus, the effects of IFN-gamma were not caused by an early block of viral replication. Possible mechanisms of IFN-gamma action include activation of the immune response, alteration of the properties of the virus, and direct protection of neurons.