Chickenpox chorioretinitis

Chickenpox Associated Retinitis and Occlusive Vasculitis in a Vaccinated Child: A Case Report and Literature Review

Either retinitis and occlusive vasculitis are rare but vision threatening ocular complications of chickenpox in children. In this case report a 13-year-old girl who developed chickenpox 2 days before complaining with visual loss in her right eye is presented. She was vaccinated one dose of varicella zoster virus (VZV) vaccine when she was 12 months old. Best corrected visual acuity was counting fingers at 1.5 m in right eye. A subtle anterior segment inflammation and mild vitritis were observed. Fundoscopic examination of right eye showed ischemia in paracentral macula and white foci of retinitis along the superotemporal branch of retinal vessels. She was hospitalized and intravenous acyclovir treatment at 3 × 10 mg/kg daily dose was started. Serum IgM and IgG for VZV were positive. Aqueous humor PCR test was also reported positive for VZV DNA. Oral methylprednisolone was added at a dose of 64 mg/day at the 3rd day acyclovir treatment. Macular edema developed at 4th week of treatment and bevacizumab was administered intravitreally. After 3 injections retinal edema subsided completely. At 6-month follow-up retinal ischemia in superotemporal periphery was observed and photocoagulation was added to treatment.

Viral posterior uveitis

The causes of posterior uveitis can be divided into infectious, autoimmune, or masquerade syndromes. Viral infections, a significant cause of sight-threatening ocular diseases in the posterior segment, include human herpesviruses, measles, rubella, and arboviruses such as dengue, West Nile, and chikungunya virus. Viral posterior uveitis may occur as an isolated ocular disease in congenital or acquired infections or as part of a systemic viral illness. Many viruses remain latent in the infected host with a risk of reactivation that depends on various factors, including virulence and host immunity, age, and comorbidities. Although some viral illnesses are self-limiting and have a good visual prognosis, others, such as cytomegalovirus retinitis or acute retinal necrosis, may result in serious complications and profound vision loss. Since some of these infections may respond well to antiviral therapy, it is important to work up all cases of posterior uveitis to rule out an infectious etiology. We review the clinical features, diagnostic tools, treatment regimens, and long-term outcomes for each of these viral posterior uveitides.

Ocular involvement associated with varicella in adults

BACKGROUND

Varicella is a common infectious disease primarily of childhood that is usually benign and self-limited. It is, however, increasingly seen in adults who are at a higher risk of severe infection. Ocular complications of varicella are relatively uncommon and have been rarely described in adults. We describe herein five adults who developed ocular involvement in association with primary varicella-zoster virus infection.

FINDINGS

Ocular manifestations included acute anterior uveitis in four eyes, with associated stromal keratitis in one of them, epithelial ulcerative keratitis in the two eyes of one patient, and acute retinal necrosis in one eye. One patient with acute anterior uveitis was treated with topical steroids and cycloplegic agents. The four other patients received topical or systemic antiviral drugs, with subsequent resolution of acute ocular inflammatory disease.

CONCLUSIONS

The spectrum of chickenpox-associated ocular complications in adults is wide. Early diagnosis and appropriate management are mandatory to improve visual outcome.

Acute retinal necrosis complicating chickenpox in a healthy adult--a case report and review of literature

Acute retinal necrosis (ARN) is known to occur in conjunction with primary varicella or chickenpox infection. The majority of ARN cases reported in the literature were of milder form with mild to moderate vitritis, limited retinitis, and rare occurrence of retinal breaks or detachment that responded well to intravenous acyclovir, with or without oral prednisolone. We report a case of unilateral ARN with marked vitritis and retinal necrosis leading to retinal breaks following chickenpox in a 32-year-old healthy lady. This patient was successfully treated with intravenous acyclovir followed by oral acyclovir and orbital floor triamcinolone injections to contain the inflammation with barrier laser therapy to secure the retinal breaks with good visual outcome. This case is unusual in its severity, and to our knowledge, orbital floor triamcinolone therapy was not used earlier to contain ARN inflammation.

Acute retinal necrosis complicating chicken pox in a healthy adult: a case report and review of literature

We report a case of unilateral acute retinal necrosis (ARN) with marked vitritis and retinal necrosis leading to retinal breaks following chicken pox successfully treated with intravenous acyclovir followed by oral acyclovir, orbital floor triamcinolone injections to contain the inflammation, and barrier laser therapy to secure the retinal breaks with good visual outcome. This case is unusual in its severity and the novel use orbital floor triamcinolone therapy to contain ARN inflammation.

Panuveitis as presenting sign of chickenpox in a young child

CASE REPORT

A previously healthy 2-year-old girl presented with severe panuveitis in her left eye. She developed chickenpox rash several days later. DNA particles of varicella-zoster virus (VZV) were detected by polymerase chain reaction (PCR) in the aqueous humor. No antiviral regimen was administered. The uveitis resolved completely after 1 week.

COMMENTS

Patients with chickenpox should undergo a thorough ophthalmologic examination at the onset of visual symptoms. Clinicians should be aware of the rare occurrence of chickenpox when evaluating a uveitis patient. If there is suspicion of chickenpox, the clinician may consider ordering serology or PCR tests.

Separation methods for acyclovir and related antiviral compounds

Acyclovir (ACV) is an antiviral drug, which selectively inhibits replication of members of the herpes group of DNA viruses with low cell toxicity. Valaciclovir (VACV), a prodrug of ACV is usually preferred in the oral treatment of viral infections, mainly herpes simplex virus (HSV). Also other analogues such as ganciclovir and penciclovir are discussed here. The former acts against cytomegalovirus (CMV) in general and the latter against CMV retinitis. The action mechanism of these antiviral drugs is presented briefly here, mainly via phosphorylation and inhibition of the viral DNA polymerase. The therapeutic use and the pharmacokinetics are also outlined. The measurement of the concentration of acyclovir and related compounds in biological samples poses a particularly significant challenge because these drugs tend to be structurally similar to endogenous substances. The analysis requires the use of highly selective analytical techniques and chromatography methods are a first choice to determine drug content in pharmaceuticals and to measure them in body fluids. Chromatography can be considered the procedure of choice for the bio-analysis of this class of antiviral compounds, as this methodology is characterised by good specificity and accuracy and it is particularly useful when metabolites need to be monitored. Among chromatographic techniques, the reversed-phase (RP) HPLC is widely used for the analysis. C18 Silica columns from 7.5 to 30 cm in length are used, the separation is carried out mainly at room temperature and less than 10 min is sufficient for the analysis at 1.0-1.5 ml/min of flow-rate. The separation methods require an isocratic system, and various authors have proposed a variety of mobile phases. The detection requires absorbance or fluorescence measurements carried out at 250-254 nm and at lambdaex=260-285 nm, lambdaem=375-380 nm, respectively. The detection limit is about 0.3-10 ng/ml but the most important aspect is related to the sample treatment, mainly when body fluids are under examination. The plasma samples obtained from human blood are pre-treated with an acid or acetonitrile deproteinization and the supernatant after centrifugation is successively extracted before RP-HPLC injection. Capillary Electrophoresis methods are also discussed. This new analytical approach might be the expected evolution, in fact the analyses are improved with regard to time and performance, in particular coated capillary as well as addition of stabilisers have been employed. The time of analysis is shortened arriving at less than half a minute. Furthermore by using an electrochemical detection, and having a calibration linearity in the range of 0.2-20.0 ng/ml, the detection limit is 0.15 microg/ml. The measurements of acyclovir and penciclovir have been presented but in the future other related drugs will probably be available using CE methods.

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.

Aciclovir. A reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic efficacy

Aciclovir (acyclovir) is a nucleoside analogue with antiviral activity in vitro against the herpes simplex viruses (HSV), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6). Topical, oral or intravenous aciclovir is well established in the treatment of ophthalmic, mucocutaneous and other HSV infections, with intravenous aciclovir the accepted treatment of choice in herpes simplex encephalitis. The efficacy of aciclovir is increased with early (preferably during the prodromal period) initiation of treatment but, despite significant clinical benefit, viral latency is not eradicated, and pretreatment frequencies of recurrence usually continue after episodic acute treatment is completed. Intravenous administration has also shown benefit in the treatment of severe complications of HSV infection in pregnancy, and neonatal HSV infections. Recurrence of HSV has been completely prevented or significantly reduced during suppressive therapy with oral aciclovir in immunocompetent patients. Use of oral aciclovir is effective but controversial in the treatment of otherwise healthy individuals with varicella (chickenpox), and in some countries it has been recommended for use only in cases which may be potentially severe. The development of rash and pain associated with herpes zoster (shingles) is attenuated with oral or intravenous aciclovir therapy, ocular involvement is prevented, and post-herpetic neuralgia appears to be decreased. Similarly, in a few patients with zoster ophthalmicus, oral aciclovir has reduced the frequency and severity of long term ocular complications and post-herpetic neuralgia, and herpes zoster oticus is improved with intravenous aciclovir. Oral aciclovir has prevented recurrence of HSV genital or orofacial infections during suppressive therapy in > 70% of immunocompetent patients in most clinical trials. Suppression of latent HSV, VZV and CMV infections has been achieved in many immunocompromised patients receiving the oral or intravenous formulations. Aciclovir also appears to offer partial protection from invasive CMV disease in CMV-seropositive bone marrow transplant recipients. The few comparative trials published have shown aciclovir to be at least as effective as other investigated antivirals in the treatment of HSV infections in immunocompetent patients, and more effective than inosine pranobex in the prophylaxis of genital herpes. Similarly, in isolated clinical trials, oral aciclovir appears as effective as topical idoxuridine and oral brivudine in some parameters in immunocompetent patients with VZV infections, and the intravenous formulation appears at least as effective as oral brivudine and intravenous vidarabine in treating these infections in immunocompromised patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Systemic antiviral drugs used in ophthalmology

Over the past two decades, the recognition of viral enzymes and proteins that can serve as molecular targets of drugs has revolutionized the treatment of viral infections. Beginning with acyclovir, a number of systemically administered agents which are both relatively safe and effective for the treatment of herpetic infections and human immunodeficiency virus (HIV) infections have become widely available. Because of increased numbers of herpes virus infections, as well as the rising epidemic of HIV infections, the ophthalmologist is, more likely than ever before to be involved in the treatment of severe and frequent ocular infections caused by herpes viruses. In addition, the acute retinal necrosis (ARN) syndrome has been demonstrated to be caused by herpes viruses and a once rare retinal infection caused by cytomegalovirus is common in patients with the acquired immunodeficiency syndrome (AIDS). In this article, four systemic antiviral drugs (Vidarabine, Acyclovir, Ganciclovir, and Foscarnet) that have demonstrated usefulness in the treatment of ophthalmic disease are reviewed in detail with regard to their mechanisms, applications, effectiveness, and side effects.

Diagnosis and management of the acute retinal necrosis (ARN) syndrome

The acute retinal necrosis (ARN) syndrome represents a specific pattern of clinical presentation for certain herpes virus infections in the posterior segment of the eye. The classically described triad of the ARN syndrome consists of (1) an arteritis and phlebitis of the retinal and choroidal vasculature, (2) a confluent, necrotizing retinitis that preferentially affects the peripheral retina, and (3) a moderate to severe vitritis. Anterior segment inflammation, optic neuritis, and late retinal detachment are also common features of this disorder. Definitive evidence now implicates at least two members of the herpes virus family; varicella zoster virus and herpes simplex virus as causative agents. This paper summarizes the clinical presentation, as well as the currently recommended treatment regimen for the ARN syndrome, highlighting recent advances that have resulted in a significant improvement in the visual prognosis for affected patients.