Emerging Viral Infections Causing Anterior Uveitis

Systemic and Ocular Manifestations of Arboviral Infections: A Review

PURPOSE

To provide an overview of pre-selected emerging arboviruses (arthropod-borne viruses) that cause ocular inflammation in humans.

METHODS

A comprehensive review of the literature published between 1997 and 2023 was conducted in PubMed database. We describe current insights into epidemiology, systemic and ocular manifestations, diagnosis, treatment, and prognosis of arboviral diseases including West Nile fever, Dengue fever, Chikungunya, Rift Valley fever, Zika, and Yellow fever.

RESULTS

Arboviruses refer to a group of ribonucleic acid viruses transmitted to humans by the bite of hematophagous arthropods, mainly mosquitoes. They mostly circulate in tropical and subtropical zones and pose important public health challenges worldwide because of rising incidence, expanding geographic range, and occurrence of prominent outbreaks as a result of climate change, travel, and globalization. The clinical signs associated with infection from these arboviruses are often inapparent, mild, or non-specific, but they may include serious, potentially disabling or life-threatening complications. A wide spectrum of ophthalmic manifestations has been described including conjunctival involvement, anterior uveitis, intermediate uveitis, various forms of posterior uveitis, maculopathy, optic neuropathy, and other neuro-ophthalmic manifestations. Diagnosis of arboviral diseases is confirmed with either real time polymerase chain reaction or serology. Management involves supportive care as there are currently no specific antiviral drug options. Corticosteroids are often used for the treatment of associated ocular inflammation. Most patients have a good visual prognosis, but there may be permanent visual impairment due to ocular structural complications in some. Community-based integrated mosquito management programs and personal protection measures against mosquito bites are the best ways to prevent human infection and disease.

CONCLUSION

Emerging arboviral diseases should be considered in the differential diagnosis of ocular inflammatory conditions in patients living in or returning from endemic regions. Early clinical consideration followed by confirmatory testing can limit or prevent unnecessary treatments for non-arboviral causes of ocular inflammation. Prevention of these infections is crucial.

Viral infections and pathogenesis of glaucoma: a comprehensive review

Glaucoma is a leading cause of irreversible blindness worldwide, caused by the gradual degeneration of retinal ganglion cells and their axons. While glaucoma is primarily considered a genetic and age-related disease, some inflammatory conditions, such as uveitis and viral-induced anterior segment inflammation, cause secondary or uveitic glaucoma. Viruses are predominant ocular pathogens and can impose both acute and chronic pathological insults to the human eye. Many viruses, including herpes simplex virus, varicella-zoster virus, cytomegalovirus, rubella virus, dengue virus, chikungunya virus, Ebola virus, and, more recently, Zika virus (ZIKV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), have been associated with sequela of either primary or secondary glaucoma. Epidemiological and clinical studies suggest the association between these viruses and subsequent glaucoma development. Despite this, the ocular manifestation and sequela of viral infections are not well understood. In fact, the association of viruses with glaucoma is considered relatively uncommon in part due to underreporting and/or lack of long-term follow-up studies. In recent years, literature on the pathological spectrum of emerging viral infections, such as ZIKV and SARS-CoV-2, has strengthened this proposition and renewed research activity in this area. Clinical studies from endemic regions as well as laboratory and preclinical investigations demonstrate a strong link between an infectious trigger and development of glaucomatous pathology. In this article, we review the current understanding of the field with a particular focus on viruses and their association with the pathogenesis of glaucoma.

Ocular Manifestations of Flavivirus Infections

Flaviviruses are a group of positive-sense, single-stranded RNA viruses predominantly transmitted by arthropods (mainly mosquitoes) that cause severe endemic infections and epidemics on a global scale. They represent a major cause of systemic morbidity and death and are expanding worldwide. Among this group, dengue fever, the West Nile virus, yellow fever, Japanese Encephalitis, and, recently, the Zika virus have been linked to a spectrum of ocular manifestations. These manifestations encompass subconjunctival hemorrhages and conjunctivitis, anterior and posterior uveitis (inclusive of vitritis, chorioretinitis, and retinal vasculitis), maculopathy, retinal hemorrhages, and optic neuritis. Clinical diagnosis of these infectious diseases is primarily based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. Diagnosis confirmation relies on laboratory testing, including RT-PCR and serological testing. Ocular involvement typically follows a self-limited course but can result in irreversible visual impairment. Effective treatments of flavivirus infections are currently unavailable. Prevention remains the mainstay for arthropod vector and zoonotic disease control. Effective vaccines are available only for the yellow fever virus, dengue virus, and Japanese Encephalitis virus. This review comprehensively summarizes the current knowledge regarding the ophthalmic manifestations of the foremost flavivirus-associated human diseases.

Assessing Strategies to Reduce the Carbon Footprint of the Annual Meeting of the American Academy of Ophthalmology

Importance

Greenhouse gas emissions associated with medical conferences have been associated with climate change, and the effects of climate change have been associated with an increased incidence of ophthalmic diseases. Identifying practical strategies associated with reducing these emissions may be warranted.

Objective

To assess greenhouse gas emissions associated with in-person and virtual meetings of the American Academy of Ophthalmology (AAO) and to conduct mitigation analyses to suggest strategies to reduce future emissions.

Design, Setting, and Participants

Quality improvement study in which attendee and conference data were used to estimate emissions from in-person (October 12 to October 15, 2019, San Francisco, California) and virtual (November 13 to November 15, 2020) AAO annual meetings for 35 104 attendees. The data were also used to perform mitigation analyses to assess whether meeting format alterations could be used to reduce future emissions. Data were analyzed from December 21, 2021, to April 18, 2022.

Exposures

Attendance at a selected meeting. Total attendance was 23 190 participants in 2019 and 11 914 participants in 2020.

Main Outcomes and Measures

Greenhouse gas emissions produced by the in-person meeting were estimated by calculating the equivalent metric tons of carbon dioxide (CO2) associated with attendee transportation, attendee accommodations, and the conference venue. Emissions produced by the virtual meeting were estimated by calculating the equivalent metric tons of CO2 associated with attendees' computer use, network data transfer, and video-conferencing server use. Mitigation analyses simulated the association of changing the meeting location and format with reductions in emissions.

Results

In this analysis, the 2019 in-person meeting produced 39 910 metric tons of CO2 (1.73 metric tons of CO2 per capita), and the 2020 virtual meeting produced 38.6 metric tons of CO2 (0.003 metric tons of CO2 per capita). Mitigation analyses showed that holding a single in-person meeting in Chicago, Illinois, rather than San Francisco, California, could be associated with transportation-related emissions reductions of 19% (emissions for the San Francisco meeting, 38 993 metric tons of CO2; for the Chicago meeting, 31 616 metric tons of CO2). Holding multiple in-person meetings in separate regions could be associated with transportation-related emissions reductions of as much as 38% (emissions for the San Francisco meeting, 38 993 metric tons of CO2; for multiple meeting scenario 2, 24 165 metric tons of CO2).

Conclusions and Relevance

This study found that the AAO's 2019 in-person meeting was associated with substantially higher greenhouse gas emissions compared with the 2020 virtual meeting, primarily due to transportation-related emissions. Increasing the proportion of virtual participants, holding the meeting in locations chosen to minimize transportation-related emissions, or offering multiple regional meeting locations may reduce the carbon footprint of future meetings.

An Overview of Indian Biomedical Research on the Chikungunya Virus with Particular Reference to Its Vaccine, an Unmet Medical Need

Chikungunya virus (CHIKV) is an infectious agent spread by mosquitos, that has engendered endemic or epidemic outbreaks of Chikungunya fever (CHIKF) in Africa, South-East Asia, America, and a few European countries. Like most tropical infections, CHIKV is frequently misdiagnosed, underreported, and underestimated; it primarily affects areas with limited resources, like developing nations. Due to its high transmission rate and lack of a preventive vaccine or effective treatments, this virus poses a serious threat to humanity. After a 32-year hiatus, CHIKV reemerged as the most significant epidemic ever reported, in India in 2006. Since then, CHIKV-related research was begun in India, and up to now, more than 800 peer-reviewed research papers have been published by Indian researchers and medical practitioners. This review gives an overview of the outbreak history and CHIKV-related research in India, to favor novel high-quality research works intending to promote effective treatment and preventive strategies, including vaccine development, against CHIKV infection.

Aspects of Antiviral Strategies Based on Different Phototherapy Approaches: Hit by the Light

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which caused the COVID-19 pandemic spreading around the world from late 2019, served as a ruthless reminder of the threat viruses pose to global public health. The synthesis of new antiviral drugs, as well as repurposing existing products, is a long-term ongoing process which has challenged the scientific community. One solution could be an effective, accessible, and rapidly available antiviral treatment based on phototherapy (PT). PT has been used to treat several diseases, and relies on the absorption of light by endogenous molecules or exogenous photosensitizers (PS). PT has often been used in cancer treatment and prophylaxis, and as a complement to established chemotherapy and immunotherapy in combined therapeutic strategy. Besides significant applications in anticancer treatment, studies have demonstrated the beneficial impact of PT on respiratory, systemic, emerging, and oncogenic viral infections. The aim of this review was to highlight the potential of PT to combat viral infections by summarizing current progress in photodynamic, photothermal, and photoacoustic approaches. Attention is drawn to the virucidal effect of PT on systemic viruses such as the human immunodeficiency virus and human herpes viruses, including the causative agent of Kaposi sarcoma, human herpes virus (HHV8). PT has good potential for disinfection in anti-norovirus research and against pandemic viruses like SARS-CoV-2.

Ocular Manifestations of Emerging Arthropod-Borne Infectious Diseases

Purpose

To review the clinical features, diagnosis, treatment modalities, and prognosis of arthropod-borne infectious diseases.

Methods

This is a narrative review on arthropod-borne infectious diseases including general and ophthalmological aspects of these infectious diseases. A comprehensive literature review between January 1983 and September 2020 was conducted in PubMed database. Epidemiology, clinical features, diagnosis, treatment, and prognosis of arthropod-borne infectious diseases were reviewed.

Results

Emergent and resurgent arthropod-borne infectious diseases are major causes of systemic morbidity and death that are expanding worldwide. Among them, bacterial and viral agents including rickettsial disease, West Nile virus, Dengue fever, Chikungunya, Rift valley fever, and Zika virus have been associated with an array of ocular manifestations. These include anterior uveitis, retinitis, chorioretinitis, retinal vasculitis, and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is primarily based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is confirmed by laboratory tests. Ocular involvement usually has a self-limited course, but it can result in persistent visual impairment. Doxycycline is the treatment of choice for rickettsial disease. There is currently no proven specific treatment for arboviral diseases. Prevention remains the mainstay for arthropod vector and zoonotic disease control.

Conclusions

Emerging arthropod vector-borne diseases should be considered in the differential diagnosis of uveitis, especially in patient living or with recent travel to endemic countries. Early clinical diagnosis, while laboratory testing is pending, is essential for proper management to prevent systemic and ocular morbidity.

Viral anterior uveitis

Viral anterior uveitis (VAU) needs to be suspected in anterior uveitis (AU) associated with elevated intraocular pressure, corneal involvement, and iris atrophic changes. Common etiologies of VAU include herpes simplex, varicella-zoster, cytomegalovirus, and rubella virus. Clinical presentations can vary from granulomatous AU with corneal involvement, Posner-Schlossman syndrome, Fuchs uveitis syndrome, and endothelitis. Due to overlapping clinical manifestations between the different viruses, diagnostic tests like polymerase chain reaction and Goldmann-Witmer coefficient analysis on the aqueous humor may help in identifying etiology to plan and monitor treatment.

Ocular manifestations of dengue

PURPOSE OF REVIEW

There are an increasing number of publications related to dengue ophthalmic manifestations and multimodality imaging related to dengue. This review summarizes the current literature, describe ocular manifestations, current using of ocular imaging/investigations, and management of ocular dengue.

RECENT FINDINGS

Ocular manifestations of dengue can be present in many stages of dengue fever including after the resolution of systemic disease. Most cases of ocular dengue will exhibit an improvement in vision spontaneously over time. Multimodal imaging such as optical coherence tomography, optical coherence tomography angiography, near-infrared imaging, and microperimetry plays an important role in the diagnosis, follow-up, quantitative measure, and help to understand the disease progression.

SUMMARY

Dengue fever can lead to a variety of ocular manifestations. The mechanisms underlying dengue-related ocular complications remain unclear. Immune-mediated mechanisms and direct viral invasion are thought to play an important role. Ophthalmologists should carefully assess patients with dengue-related ophthalmic disease because some patients may have poor visual acuity and exhibit refractoriness to treatment. Treatment with systemic corticosteroids may benefit those patients with poor presenting visual acuity, progressive ocular symptoms, and lesions involving the optic nerve and/or threatening the macula.