Acute anterior uveitis and optic neuritis as ocular complications of influenza A infection in an 11-year-old boy

Infectious optic neuropathy (ION), how to recognise it and manage it

Optic neuropathy can be of infectious or non-infectious/idiopathic aetiology. Many infectious organisms can cause optic neuropathy that can be of varied presentation including papillitis, retrobulbar optic neuritis, neuroretinitis, and optic perineuritis. Detailed history, ocular, systemic/neurologic examination along with appropriate laboratory evaluation can help clinicians to identify the infectious agent causing optic neuropathy. In spite of recent advanced techniques in serological testing and molecular diagnostics like polymerase chain reaction (PCR), the identification of these pathogens is still a diagnostic challenge. It is ideal to have an infectious disease (ID) consultant in the management team, as most of these infections are multisystem involving diseases. Most infectious agents can be effectively treated with specific antibiotics, with or without corticosteroid therapy, but visual recovery is highly variable and depends entirely on early diagnosis of the causative agent. This review article will provide an overview of common pathogens involved in ION and will describe their management paradigms.

Response of Human Retinal Microvascular Endothelial Cells to Influenza A (H1N1) Infection and the Underlying Molecular Mechanism

Purpose

Whether H1N1 infection-associated ocular manifestations result from direct viral infections or systemic complications remains unclear. This study aimed to comprehensively elucidate the underlying causes and mechanism.

Method

TCID50 assays was performed at 24, 48, and 72 hours to verify the infection of H1N1 in human retinal microvascular endothelial cells (HRMECs). The changes in gene expression profiles of HRMECs at 24, 48, and 72 hours were characterized using RNA sequencing technology. Differentially expressed genes (DEGs) were validated using real-time quantitative polymerase chain reaction and Western blotting. CCK-8 assay and scratch assay were performed to evaluate whether there was a potential improvement of proliferation and migration in H1N1-infected cells after oseltamivir intervention.

Results

H1N1 can infect and replicate within HRMECs, leading to cell rounding and detachment. After H1N1 infection of HRMECs, 2562 DEGs were identified, including 1748 upregulated ones and 814 downregulated ones. These DEGs primarily involved in processes such as inflammation and immune response, cytokine-cytokine receptor interaction, signal transduction regulation, and cell adhesion. The elevated expression levels of CXCL10, CXCL11, CCL5, TLR3, C3, IFNB1, IFNG, STAT1, HLA, and TNFSF10 after H1N1 infection were reduced by oseltamivir intervention, reaching levels comparable to those in the uninfected group. The impaired cell proliferation and migration after H1N1 infection was improved by oseltamivir intervention.

Conclusions

This study confirmed that H1N1 can infect HRMECs, leading to the upregulation of chemokines, which may cause inflammation and destruction of the blood-retina barrier. Moreover, early oseltamivir administration may reduce retinal inflammation and hemorrhage in patients infected with H1N1.

Optic disc edema with peripapillary serous retinal detachment as the presenting sign of necrotizing herpetic retinitis

Purpose

To describe an atypical case of necrotizing herpetic retinitis (NHR) that presented initially with mild anterior uveitis, optic disc swelling, and peripapillary serous retinal detachment (SRD).

Observations

A 48-year-old Asian Indian man presented with blurred central vision and pain in his left eye. Examination revealed mild anterior chamber inflammation, optic disc swelling, and a peripapillary SRD in the affected eye. Multimodal imaging, including widefield fluorescein angiography, showed optic disc leakage and confirmed the presence of a peripapillary SRD, but was otherwise unremarkable with no evidence of retinitis. The patient was diagnosed with presumed Vogt-Koyanagi-Harada disease and was treated with systemic corticosteroids. While there was objective visual improvement initially, the patient subsequently noted peripheral vision loss and was found to have peripheral necrotizing retinitis and occlusive retinal vasculitis in affected eye. Polymerase chain reaction-based testing of aqueous humor detected varicella zoster virus DNA, confirming the diagnosis of NHR.

Conclusion and importance

Optic disc edema and peripapillary SRD may precede the development of overt retinitis in some patients with NHR.

Ocular manifestations of emerging viral diseases

Emerging infectious diseases (EIDs) are an increasing threat to public health on a global scale. In recent times, the most prominent outbreaks have constituted RNA viruses, spreading via droplets (COVID-19 and Influenza A H1N1), directly between humans (Ebola and Marburg), via arthropod vectors (Dengue, Zika, West Nile, Chikungunya, Crimean Congo) and zoonotically (Lassa fever, Nipah, Rift Valley fever, Hantaviruses). However, specific approved antiviral therapies and vaccine availability are scarce, and public health measures remain critical. Patients can present with a spectrum of ocular manifestations. Emerging infectious diseases should therefore be considered in the differential diagnosis of ocular inflammatory conditions in patients inhabiting or returning from endemic territories, and more general vigilance is advisable in the context of a global pandemic. Eye specialists are in a position to facilitate swift diagnosis, improve clinical outcomes, and contribute to wider public health efforts during outbreaks. This article reviews those emerging viral diseases associated with reports of ocular manifestations and summarizes details pertinent to practicing eye specialists.

Bilateral optic neuritis with spine demyelination associated with influenza A H1N1 infection

Purpose

To report a rare case of optic neuritis with spine demyelination following H1N1 virus infection.

Observation

A 66-year-old female presented with decreased vision in both eyes (left > right) following a recent episode of fever and flu. She was diagnosed as H1N1 infection confirmed by viral antigen analysis of throat swab. On examination, she had a profound vision drop in the left eye with optic disc edema. MRI brain and orbit revealed bilateral optic nerve and frontal dural thickening with a ring-enhancing lesion in the right frontal lobe. MRI spine showed long cord signals at T1-T7 suggestive of demyelination. The patient had a complete recovery of vision and visual fields after intravenous and oral steroids.

Conclusion/Importance

Influenza A virus can manifest with a wide range of symptoms including flu-like illness to neurological complications. This case highlights optic neuritis as a presenting feature of H1N1 infection.

Fungal retinitis following influenza virus type A (H1N1) infection

A 43-year-old male presented with left eye foveal retinits causing an acute visual loss following influenza virus type A infection (H1N1 infection or Swine flu). Considering viral (influenza) etiology, a prompt treatment with oral corticosteroids was started. But an initial poor response prompted an immediate diagnostic vitrectomy, which revealed Candida albicans. The retinitis healed with scar formation following anti-fungal therapy. This case highlights that even in the setting of an acute retinitis in an immunocompetent patient with recent history of viral systemic illness, a high index of suspicion of a fungal (rather than viral) infection should be kept in mind.

Primary Ocular Toxoplasmosis Presenting to Uveitis Services in a Non-endemic Setting

PURPOSE

This study sought to describe the different clinical features and presentations of primary ocular toxoplasmosis in a setting not demonstrating an outbreak of disease.

METHODS

This was a retrospective review of patients presenting to uveitis management services in Auckland and Hamilton, New Zealand between 2003 to 2018 with uveitis and positive toxoplasmosis immunoglobulin M serology.

RESULTS

We identified 16 patients with primary acquired toxoplasmosis infection and ocular involvement. The mean age was 53 years. Systemic symptoms were reported in 56% (9 / 16). Visual acuity was reduced to 20 / 30 or less in 50% of patients (8 / 16). A single focus of retinitis without a pigmented scar was the salient clinical feature in 69% (11 / 16). Optic nerve inflammation was the sole clinical finding in 19% (3 / 16). Bilateral arterial vasculitis was the sole clinical finding in 13% (2 / 16). A delay in the diagnosis of toxoplasmosis of more than two weeks occurred in 38% (6 / 16) due to an initial alternative diagnosis. Antibiotic therapy was prescribed in all cases. Vision was maintained or improved in 69% (11 / 16) at the most recent follow-up visit (15 months to 10 years). Relapse occurred in 69% (11 / 16), typically within four years from the initial presentation.

CONCLUSIONS

Primary ocular toxoplasmosis presenting in adulthood is a relatively uncommon cause of posterior uveitis in New Zealand. This condition should be considered in any patient presenting with retinitis or optic nerve inflammation without a retinochoroidal scar. This disease tends to relapse; thus, close follow-up is required.

Pediatric viral orbital cellulites secondary to H1N1 infection: A case report

A 10-year-old boy admitted for high-grade fever and pneumonia developed left preseptal and early orbital cellulitis, unresponsive to higher intravenous antibiotics. He received oseltamivir, on testing positive for H1N1 virus on the nasopharyngeal and throat swabs. There was dramatic improvement with resolution of orbital cellulitis within 24 h of starting oseltamivir. We report a very rare presentation of pediatric orbital cellulitis secondary to systemic H1N1 infection. Prompt investigations and timely treatment with oseltamivir aided in complete resolution, avoiding vision and life-threatening complications.

Ocular Complications in Influenza Virus Infection

Purpose: To describe a case series of ocular complications associated with upper respiratory tract infections. Methods: Four patients aged 21-61 years (three females, one male) had confirmed ocular complications connected with a general upper respiratory tract infection with myalgia and fever. Ophthalmological examination, including a visual acuity test, a slit-lamp exam, intraocular pressure measurements, fluorescein and indocyanine green angiography, optical coherence tomography (OCT), and diagnostic tests for influenza were performed in the patients (RT-PCR, HAI). Results: Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) was diagnosed in three patients and serous macular detachment (SME) in one. Influenza virus infection was confirmed by molecular biological methods (RT-PCR) or the hemagglutination inhibition test (HAI) in two patients. All patients were treated with systemic prednisone. Conclusion: A coincidence between APMPPE and SME epitheliopathy and influenza virus infection was observed in different months of a given epidemic season.

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.

Optic neuritis and acute anterior uveitis associated with influenza A infection: a case report

Background

A few reports have described ocular complications of influenza A infection, such as impaired ocular movement, parasympathetic ocular nerve, keratitis, macular lesion, and frosted branch angiitis. We encountered a rare case of acute anterior uveitis and optic neuritis associated with influenza A infection.

Case presentation

A 70-year-old man presented with symptoms of upper respiratory tract infection. A rapid diagnostic test showed a positive result for influenza A. At the same time, he developed ocular symptoms including blurred vision with optic disk edema and hemorrhage in the left eye, and bilateral red eyes. Multiplex polymerase chain reaction performed on aqueous humor sample detected no viral infection. Visual field testing with a Goldmann perimeter showed central and paracentral scotomas in the left eye. In addition to antiviral agent (oseltamivir phosphate 75 mg), the patient was prescribed topical prednisolone acetate ophthalmic suspension eye drops every 5 hours and high-dose intravenous methylprednisolone 1,000 mg daily for 3 days. Two months later, his best-corrected visual acuity improved to 20/50 with regression of visual field defects in his left eye.

Conclusion

We report a case of bilateral acute anterior uveitis and unilateral optic neuritis concomitant with influenza A infection. Topical and systemic corticosteroids were effective to resolve acute anterior uveitis and neuritis. Analysis of aqueous humor sample suggested that acute anterior uveitis and optic neuritis in this case were not caused by influenza A virus infection per se but by autoimmune mechanism.

Infectious optic neuropathies: a clinical update

Different forms of optic neuropathy causing visual impairment of varying severity have been reported in association with a wide variety of infectious agents. Proper clinical diagnosis of any of these infectious conditions is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular findings. Diagnosis is confirmed by serologic testing and polymerase chain reaction in selected cases. Treatment of infectious optic neuropathies involves the use of specific anti-infectious drugs and corticosteroids to suppress the associated inflammatory reaction. The visual prognosis is generally good, but persistent severe vision loss with optic atrophy can occur. This review presents optic neuropathies caused by specific viral, bacterial, parasitic, and fungal diseases.

Optic neuritis associated with influenza B virus meningoencephalitis

Various postinfectious neurological manifestations have been described associated to influenza viruses. Optic neuritis is a serious, often reversible disease reported among several infectious diseases and vaccines complications. We report a case of optic neuritis following an influenza B virus infection in a 10-year-old male.

Ocular tropism of respiratory viruses

Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism.

Influenza virus respiratory infection and transmission following ocular inoculation in ferrets

While influenza viruses are a common respiratory pathogen, sporadic reports of conjunctivitis following human infection demonstrates the ability of this virus to cause disease outside of the respiratory tract. The ocular surface represents both a potential site of virus replication and a portal of entry for establishment of a respiratory infection. However, the properties which govern ocular tropism of influenza viruses, the mechanisms of virus spread from ocular to respiratory tissue, and the potential differences in respiratory disease initiated from different exposure routes are poorly understood. Here, we established a ferret model of ocular inoculation to explore the development of virus pathogenicity and transmissibility following influenza virus exposure by the ocular route. We found that multiple subtypes of human and avian influenza viruses mounted a productive virus infection in the upper respiratory tract of ferrets following ocular inoculation, and were additionally detected in ocular tissue during the acute phase of infection. H5N1 viruses maintained their ability for systemic spread and lethal infection following inoculation by the ocular route. Replication-independent deposition of virus inoculum from ocular to respiratory tissue was limited to the nares and upper trachea, unlike traditional intranasal inoculation which results in virus deposition in both upper and lower respiratory tract tissues. Despite high titers of replicating transmissible seasonal viruses in the upper respiratory tract of ferrets inoculated by the ocular route, virus transmissibility to naïve contacts by respiratory droplets was reduced following ocular inoculation. These data improve our understanding of the mechanisms of virus spread following ocular exposure and highlight differences in the establishment of respiratory disease and virus transmissibility following use of different inoculation volumes and routes.

Most infections with influenza virus result in respiratory disease. However, influenza viruses of the H7 subtype frequently cause ocular and not respiratory symptoms during human infection, demonstrating that the eye represents an alternate location for influenza viruses to infect humans. Using a ferret model, we studied the ability of influenza viruses to cause disease following ocular inoculation. We found that both human and avian influenza viruses could use the eye as a portal of entry to establish a respiratory infection in ferrets. Influenza viruses were also detected in ocular samples taken from ferrets during virus infection. We identified that influenza viruses spread to different tissues in ferrets when inoculated by ocular or respiratory routes, and that these differences affected the transmissibility of influenza viruses in this model. This study is the first to confirm that virus can spread from the eye to the respiratory tract in a replication-independent manner, and offers greater insight in understanding the ability of influenza viruses of all subtypes to cause human infection by the ocular route.