Myopic shift and its mechanism in nephropathia epidemica or Puumala virus infection

Ophthalmic implications of biological threat agents according to the chemical, biological, radiological, nuclear, and explosives framework

As technology continues to evolve, the possibility for a wide range of dangers to people, organizations, and countries escalate globally. The United States federal government classifies types of threats with the capability of inflicting mass casualties and societal disruption as Chemical, Biological, Radiological, Nuclear, and Energetics/Explosives (CBRNE). Such incidents encompass accidental and intentional events ranging from weapons of mass destruction and bioterrorism to fires or spills involving hazardous or radiologic material. All of these have the capacity to inflict death or severe physical, neurological, and/or sensorial disabilities if injuries are not diagnosed and treated in a timely manner. Ophthalmic injury can provide important insight into understanding and treating patients impacted by CBRNE agents; however, improper ophthalmic management can result in suboptimal patient outcomes. This review specifically addresses the biological agents the Center for Disease Control and Prevention (CDC) deems to have the greatest capacity for bioterrorism. CBRNE biological agents, encompassing pathogens and organic toxins, are further subdivided into categories A, B, and C according to their national security threat level. In our compendium of these biological agents, we address their respective CDC category, systemic and ophthalmic manifestations, route of transmission and personal protective equipment considerations as well as pertinent vaccination and treatment guidelines.

Ophthalmic consequences of viral hemorrhagic fevers: Insights from the clinic and laboratory

Viral hemorrhagic fevers (VHFs) are a diverse group of RNA virus-mediated systemic diseases with significant morbidity and mortality and represent a significant public health concern. Given the high systemic morbidity and mortality in a number of these entities, delays in diagnosis can lead to downstream public health consequences. Many viral hemorrhagic fevers have ophthalmic manifestations and ophthalmologists thus play a key role in disease recognition and the management of ocular complications associated with specific hemorrhagic fevers. This review summarizes the key ophthalmic consequences of viral hemorrhagic fevers, viral disease pathogenesis, disease findings, and areas of unmet research need.

Infections and glaucoma

Glaucoma is an intraocular pressure-related ophthalmic disease with multiple causes that results in an optic neuropathy and vision loss. Intraocular pressure elevation is among its strongest risk factors. While glaucoma is mostly primary in etiology, secondary glaucoma is not infrequent. Recognizing its cause is imperative, since treatment is often different depending on the pathophysiologic mechanism. Numerous clinically relevant ophthalmic infections can result in robust inflammatory responses that may result in pressure elevation or intraocular anatomic configurations that predispose to pressure elevation. Knowing the mechanisms by which these infections can lead to glaucoma is critical in treating, and we consolidate what is currently known in regards to how infectious diseases lead to glaucoma.

Central Nervous System and Ocular Manifestations in Puumala Hantavirus Infection

Puumala hantavirus (PUUV), carried and spread by the bank vole (Myodes glareolus), causes a mild form of hemorrhagic fever with renal syndrome (HFRS) called nephropathia epidemica (NE). Acute high fever, acute kidney injury (AKI), thrombocytopenia, and hematuria are typical features of this syndrome. In addition, headache, blurred vision, insomnia, vertigo, and nausea are commonly associated with the disease. This review explores the mechanisms and presentations of ocular and central nervous system involvement in acute NE.

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.

Puumala hantavirus: an imaging review

Puumala virus (PUUV) is the most common hantavirus in Europe. It is known to cause nephropathia epidemica, which is considered a mild type of hemorrhagic fever with renal syndrome. However, it does not only involve the kidneys and is rarely accompanied by symptomatic hemorrhage. We review the imaging abnormalities caused by PUUV infection, from head to pelvis, emphasizing the broad spectrum of possible findings and bringing further support to a previously suggested denomination "Hantavirus disease" that would encompass all clinical manifestations. Although non-specific, knowledge of radiological appearances is useful to support clinically suspected PUUV infection, before confirmation by serology.

Acute angle-closure glaucoma with choroidal effusion revealing a hantavirus infection: Description of ultrasound biomicroscopy imagery and optical coherence tomography Visante

PURPOSE

To report a case of bilateral angle-closure associated with systemic hantavirus infection.

MATERIALS AND METHODS

A 32-year-old Caucasian man was referred with blurred vision, fever, cough, dyspnea and thrombocytopenia. Ophthalmologic examination revealed myopic shift, elevated intraocular pressure (30 mmHg right eye and 24 mmHg left eye), corneal edema, iridocorneal angle closure and shallow anterior chamber. Ciliochoroidal effusion was detected on anterior segment optical coherence tomography and ultrasound biomicroscopy. Serologic test and polymerase chain reaction confirmed the diagnosis of hantavirus infection and the serotype Puumala. On the sixth day after he started topical anti-glaucoma and cycloplegic medications, the anterior chamber and iridocorneal angles were normalized with disappearance of ciliochoroidal effusion.

CONCLUSION

Puumala hantavirus infection is an exceptional cause of acute bilateral angle-closure combined with ciliochoroidal effusion.

Ocular Pathology: Role of Emerging Viruses in the Asia-Pacific Region-A Review

The role of viral infections in ocular pathology varies greatly, involving all the components of the eye. Some viruses like herpes simplex, herpes zoster, adenovirus, enterovirus 70, influenza virus, human immunodeficiency virus, and cytomegalovirus are well-known for their role in ocular pathology. In recent years, emerging and resurging viral infections represent an important public health problem. The Asia-Pacific region has witnessed a number of pandemic and epidemic outbreaks caused by these viruses during the last 2 decades. The number of ocular complications being reported in patients of these viral infections has also increased significantly during this period. Ophthalmologists and physicians should be aware of ocular manifestations of newly emerging or resurging viral diseases. We conducted a review of the literature published during the last 20 years with the objectives of finding out outbreaks of emerging and reemerging viruses in the Asia-Pacific region and finding out any ocular involvement in these viral infections. An iterative search of the MEDLINE and the Google databases was made using the search terms emerging virus, ocular manifestations, ocular complications, Chikungunya, Dengue, Japanese encephalitis, West Nile fever, Kyasanur forest disease, Rift valley fever, Hantavirus, Henipavirus, Influenza virus, Enterovirus 71, and Asia-Pacific region, separately and with reported ocular involvement in combination. This review article discusses the epidemiology and the systemic and ocular manifestations of all emerging viral infections with reported ocular involvement in the Asia-Pacific region.

An emerging infectious cause of renal impairment in the UK

Hantaviruses are endemic in many central European countries, particularly the Balkans, infection causing non-specific 'flu-like symptoms and renal dysfunction which is self-limiting in the majority of cases. In this case, there was a diagnostic delay, resulting in numerous unnecessary investigations, prolonged hospital stay and almost an invasive renal biopsy. A travel history is therefore essential, to establish travel to an endemic region within the previous 2-6 weeks. With increasing travel and immigration, hantavirus is likely to be seen more frequently as an imported infection into the UK. However, further research is required to establish the potential for acquisition of infection here, as the animal host, the bank vole, is part of local wildlife. Therefore, the authors urge physicians to be alert to this possibility when faced with acute renal failure in association with an undiagnosed febrile illness, particularly when there is a history of an appropriate environmental or animal exposure.

A Case Report of Haemorrhagic Fever with Renal Syndrome

A 42-year-old air-conditioning technician presented with abdominal pain and influenza like illness eventually developed thrombocytopenia and haemoconcentration with renal impairment shortly after admission. The patient required a section of haemodialysis for acute oliguric renal failure with fluid overload. He developed diuresis and his clinical condition was improved with supportive treatment. Hantaan virus infection with haemorrhagic fever with renal syndrome was confirmed by serologic test.

Nephropathia epidemica (puumala virus infection) in Austrian children

From 2000 to 2007, 19 Austrian children (aged 6-18 years) had serologically verified nephropathia epidemica. Common clinical features were abdominal/flank/back pain, fever, nausea, vomiting, headache, and transient visual disturbances. Acute renal failure was present in 18 (95%) patients. All patients recovered completely. Childhood nephropathia epidemica in Austria takes a similar course to those reported for Northern European Puumala virus strains.

A global perspective on hantavirus ecology, epidemiology, and disease

Hantaviruses are enzootic viruses that maintain persistent infections in their rodent hosts without apparent disease symptoms. The spillover of these viruses to humans can lead to one of two serious illnesses, hantavirus pulmonary syndrome and hemorrhagic fever with renal syndrome. In recent years, there has been an improved understanding of the epidemiology, pathogenesis, and natural history of these viruses following an increase in the number of outbreaks in the Americas. In this review, current concepts regarding the ecology of and disease associated with these serious human pathogens are presented. Priorities for future research suggest an integration of the ecology and evolution of these and other host-virus ecosystems through modeling and hypothesis-driven research with the risk of emergence, host switching/spillover, and disease transmission to humans.

Visusverlust und akutes Nierenversagen bei einer 28-jährigen aktiven Reiterin

A 28-year old active sportswoman was admitted to hospital suffering from fever, menigeal irritation, acute myopia and progressive acute renal failure. Showing signs of polyserositis in combination with pulmonary granulomatous changes a collagenosis as well as an atypical pneumonia was excluded first. Due to the renal loss of function a renal biopsy was taken with the typical histological result of a hantavirus infection. This could be confirmed serologically in the following. With symptomatic treatment the patient had an uneventful complete recovery during the next four weeks.

Hantavirus infections in Europe

Hantaviruses are enveloped RNA viruses each carried by a specific rodent species. Three hantaviruses, Puumala, Dobrava, and Saaremaa viruses, are known to cause haemorrhagic fever with renal syndrome. In Europe. Puumala causes a generally mild disease, nephropathia epidemica, which presents most commonly with fever, headache, gastrointestinal symptoms, impaired renal function, and blurred vision, whereas Dobrava infections often also have haemorrhagic complications. There are few available data about the clinical picture of confirmed Saaremaa infections, but epidemiological evidence suggests that it is less pathogenic than Dobrava, and that Saaremaa infections are more similar to nephropathia epidemica caused by Puumala. Along with its rodent host, the bank vole (Clethrionomys glareolus), Puumala is reported throughout most of Europe (excluding the Mediterranean region), whereas Dobrava, carried by the yellow-necked mouse (Apodemus flavicollis), and Saaremaa, carried by the striped field mouse (Apodemus agrarius), are reported mainly in eastern and central Europe. The diagnosis of acute hantavirus infection is based on the detection of virus-specific IgM. Whereas Puumala is distinct, Dobrava and Saaremaa are genetically and antigenically very closely related and were previously thought to be variants of the same virus. Typing of a specific hantavirus infection requires neutralisation antibody assays or reverse transcriptase PCR and sequencing.

Pathogenesis of transient high myopia after blunt eye trauma

OBJECTIVE

To determine the pathogenesis of transient high myopia after blunt eye trauma.

DESIGN

Two observational case reports and literature review.

METHODS

Refraction was measured in two patients with an autorefractometer in the acute and convalescent stages after a blunt eye injury. The anterior chamber angle, the ciliary body, and the choroid were examined by ultrasound biomicroscopy (UBM) in the acute and convalescent stages. In one patient, the anterior chamber depth, lens thickness, and axial length were measured by A-scan ultrasonography in the acute and convalescent stages.

MAIN OUTCOME MEASURES

Comparison of the refraction, anterior chamber depth, lens thickness, axial length, and the UBM-determined appearance of the choroid and ciliary body during the acute stage with the values during the convalescent stages.

RESULTS

The first patient showed a myopic shift of -9.75 diopters (D) and an anterior chamber shallowing of 0.94 mm measured 3 days after trauma by an air bag inflation compared with the measurements at the convalescent phase. UBM showed an annular ciliochoroidal effusion with ciliary body edema, anterior rotation of the ciliary processes, and disappearance of the ciliary sulcus. Eleven days after the injury, these UBM findings normalized, and the myopia decreased to -0.75 D, 27 days after trauma. The second patient had a myopic shift of -8.9 D compared with the convalescent phase, immediately after blunt trauma by a firework. Seven days after the injury, UBM revealed a partial cyclodialysis in addition to findings similar to those in the first patient. Ten days after injury, a myopic shift (-4.75 D), anterior chamber shallowing (by 1.1 mm), and thickening of the crystalline lens (by 0.27 mm) were observed compared with the convalescent phase. Associated UBM findings confirmed the anterior shift of the lens-iris diaphragm. Seventeen days after trauma, the UBM findings, including the cyclodialysis, were normalized, and the myopia had decreased to -1.0 D.

CONCLUSIONS

Transient high myopia after blunt trauma is caused by anatomic changes in the ciliary body and crystalline lens. The anterior shift of the lens-iris diaphragm caused by ciliochoroidal effusion with ciliary body edema and thickening of the crystalline lens from blunt eye trauma are involved in traumatic high myopia.

Pathogenesis of puumala and other hantavirus infections

Hantaviruses are rodent/insectivore-borne negative-stranded RNA viruses which belong to the Bunyaviridae family. They do not cause any symptomatic disease in their adult carrier rodents, but in humans they are aetiologic agents of haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), both associated with a significant mortality. In cell culture hantaviruses do not cause cytopathic effects and the mechanisms of disease in man are not well understood. Increased capillary permeability is a central phenomenon in the pathogenesis of hantavirus infections. Although the viruses have in vivo a predilection for endothelial cells, it is presumed that inflammatory mediators of the host immune response play a significant role in the capillary leak that may produce abrupt hypotension and shock in severely ill patients. Mediators released by activated macrophages including NO and TNF-alpha are considered important. The pathogenesis of renal failure in HFRS also awaits to be resolved. This review summarises what is known about these phenomena and discusses also the molecular basis of the putative virulence factors of hantaviruses. Finally, the genetic predisposition and HLA association with severe Puumala virus infection will be discussed. Copyright 1998 John Wiley & Sons, Ltd.

Central nervous system and ophthalmic involvement in nephropathia epidemica (European type of haemorrhagic fever with renal syndrome)

Central nervous system (CNS) - related symptoms occur in haemorrhagic fever with renal syndrome (HFRS). To study the CNS and ophthalmic involvement in nephropathia epidemica (NE), the European type of HFRS, we included 26 patients in a prospective study. Most common CNS-related symptoms were headache (96%), insomnia (83%), vertigo (79%), nausea (79%), and vomiting (71%). Ophthalmic symptoms were reported by 82% of patients; 41% had photophobia and 50% had impaired vision. A transient loss of vision was recorded in one patient, who also had a generalized seizure. Minor white matter lesions were found in about half of the patients investigated with brain magnetic resonance imaging (MRI). Electroencephalography (EEG) showed severe alterations in only one patient, and slight and reversible patterns in another two patients. Neopterin, interleukin-6 and interferon-gamma levels in the cerebrospinal fluid (CSF) were elevated, which may indicate immune activation. However, we found no evidence of intrathecal NE virus replication. We conclude that CNS-related symptoms are common in NE, and transient ophthalmic involvement can be demonstrated in about half of the patients.

Ocular characteristics in nephropathia epidemica or Puumala virus infection

PURPOSE

We documented the largest series so far concerning the ocular characteristics of nephropathia epidemica.

METHODS

A total of 37 consecutive nephropathia epidemica patients underwent a comprehensive ophthalmic examination during hospitalization for systemic infection, and a control examination after recovery.

RESULTS

The most common ocular symptoms were: frontal headache or periocular pain (75.6%), blurred vision (54.1%) and photophobia (10.8%). The best corrected visual acuity of 7 patients (18.9%) was reduced during the acute phase as compared to the later control examination. Myopic shift was found in 15 patients (40.5%), three of whom (8.1%) developed real transient myopia. There were no attacks of angle closure glaucoma in this series. On the contrary, the intraocular pressure was decreased in 49 eyes (66.2%) during the acute stage of the disease. Lid edema was present in 28 eyes (37.8%), conjunctival injection in 20 eyes (27.0%), chemosis in 8 eyes (10.8%) and subconjuctival bleeding in 3 eyes (4.1%). Signs of acute anterior uveitis were found in 10 eyes (13.5%), however, this resolved without treatment. In one eye retinal edema with hemorrhages was detected. Ultrasonography revealed narrowing of the anterior chamber during the acute phase in 69 eyes (93.2%) and thickening of the crystalline lens in 64 eyes (86.5%).

CONCLUSION

Ophthalmic findings in nephropathia epidemica are not uncommon. The symmetry of the clinical manifestations reflects the systemic nature of the underlying infection.

Intraocular pressure changes in nephropathia epidemica. A prospective study of 37 patients with acute systemic Puumala virus infection

BACKGROUND

Nephropathia epidemica is a zoonose in the group of hemorrhagic fevers with renal syndrome and is caused by Puumala virus in Hantavirus genus. The purpose of this study is to find out how the intraocular pressure (IOP) is affected by the acute phase of this disease and how it relates to the previous case reports on angleclosure glaucoma attacks.

PATIENTS AND METHODS

The prospective study documents IOP and anterior chamber depth measurements in 37 patients during the winter epidemic of nephropathia epidemica from 1992 to 1993. Ocular examinations were performed during the acute systemic infection and after clinical recovery.

RESULTS

The IOP was lower and the anterior chamber shallower in the acute phase than after the clinical recovery of nephropathic epidemica. The mean differences in IOP were 1.8 mmHg in the right eye and 1.9 mmHg in the left (P < 0.001) and the mean differences in the anterior chamber depth were 0.22 mm in the right eye and 0.20 mm in the left (P < 0.001). No acute angle-closure attacks with highly elevated IOP were encountered in this study. The mean IOP did not rise higher than 14.3 mmHg in both eyes after the clinical recovery of systemic infection.

CONCLUSION

In contradistinction to earlier assumptions, Puumala virus infection decreases the IOP. Shallowing of anterior chamber and narrowing of the anterior chamber angle in the acute phase of nephropathia epidemica did not lead to angle-closure attacks in this series.