Viral posterior uveitis

Possible viral agents to consider in the differential diagnosis of blepharoconjunctivitis

BACKGROUND

Blepharoconjunctivitis poses a diagnostic challenge due to its diverse etiology, including viral infections. Blepharoconjunctivits can be acute or chronic, self-limiting, or needing medical therapy.

AIM

To review possible viral agents crucial for accurate differential diagnosis in cases of blepharoconjunctivitis.

METHODS

The PubMed database was searched for records relating to viral blepharoconjunctivitis. The search string generated was “("virally"[All Fields] OR "virals"[All Fields] OR "virology"[MeSH Terms] OR "virology"[All Fields] OR "viral"[All Fields]) AND "Blepharoconjunctivitis"[All Fields]".

RESULTS

A total of 24 publications were generated from the search string. Reference lists from each relevant article were also searched for more information and included in this review. Viral etiologies such as adenovirus, herpes simplex virus (HSV), varicella-zoster virus (VZV), and Epstein-Barr virus (EBV) are frequently implicated. Adenoviral infections manifest with follicular conjunctivitis and preauricular lymphadenopathy, often presenting as epidemic keratoconjunctivitis. HSV and VZV infections can result in herpetic keratitis and may exhibit characteristic dendritic corneal ulcers. EBV, although less common, can cause unilateral or bilateral follicular conjunctivitis, particularly in immunocompromised individuals. Other potential viral agents, such as enteroviruses and molluscum contagiosum virus, should also be considered, especially in pediatric cases.

CONCLUSION

Prompt recognition of these viral etiologies is essential for appropriate management and prevention of complications. Thus, a thorough understanding of the clinical presentation, epidemiology, and diagnostic modalities is crucial for accurate identification and management of viral blepharoconjunctivitis.

Incident Ocular Inflammation After COVID-19 Infection in a US Veteran Population

PURPOSE

To investigate whether COVID-19 infection is a risk factor for incident ocular inflammatory disease.

DESIGN

Retrospective case-crossover study.

METHODS

The US Veterans Health Administration Corporate Data Warehouse was used to identify patients with positive COVID-19 testing and incident ocular inflammatory disease between March 2020 and May 2022. The timing of incident ocular inflammation and COVID-19 testing was assessed for each participant to determine whether positive COVID-19 testing occurred 0-60 days prior to incident ocular inflammation diagnosis (risk period) or 15-75 days after incident ocular inflammation diagnosis (control period). The main outcome measure was the odds of positive COVID-19 testing in the risk period versus control period.

RESULTS

Of the 1006 patients with incident ocular inflammation and a positive COVID-19 test in the study period, the age mean ± standard deviation was 62.6 ± 9.8 years and 840 (83%) were male. The odds of COVID-19 exposure was higher in the risk than control period (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.04-2.36; P = 0.03). Ocular inflammation was more likely to be bilateral in the risk period (OR, 3.97; 95% CI, 1.01-23.01; P = 0.03). Other ocular features and demographic characteristics were similar in the risk and control periods. Most cases of ocular inflammation were quiescent at the most recent eye examination.

CONCLUSIONS

Incident ocular inflammation is associated with COVID-19 infection, but the increased risk is small, and the ocular inflammation is typically acute.

Systemic and Ophthalmic Manifestations of Chikungunya Fever

PURPOSE

Chikungunya is a re-emerging viral infection across the globe. The purpose of this article is to review the systemic and ophthalmic manifestations associated with chikungunya fever.

METHOD

A review of literature was conducted using online databases.

RESULTS

In this report, we have reviewed the presently available literature on uveitis caused by chikungunya and highlighted the current knowledge of its clinical manifestations, imaging features, laboratory diagnostics, and the available therapeutic modalities from the systemic and ophthalmic standpoint.

CONCLUSIONS

Ocular involvement in chikungunya infection may occur at the time of systemic manifestations or it may occur as a delayed presentation many weeks after the fever. Treatment relies on a supportive therapy for systemic illness. Treatment of ocular manifestation depends on the type of manifestations and usually includes a combination of topical and oral steroids.

Acute Retinal Necrosis: Experience in a Reference Center in Santander - Colombia

INTRODUCTION

Acute retinal necrosis (ARN) is a severe eye disease demanding swift treatment to prevent blindness. Early action involving antiviral medications and corticosteroids is crucial for optimal visual outcomes.

OBJECTIVE

We present an ARN case series showcasing treatment experience and results.

METHODOLOGY

Patients diagnosed with ARN based on SUN Working Group 2021 criteria were included; all underwent comprehensive eye exams, PCR analysis, and imaging.

RESULTS

 Eight patients were studied; PCR confirmed ARN in six. Induction treatment, either oral valacyclovir (5/8) or intravenous acyclovir (3/8), lasted 10-14 days. Maintenance included oral valacyclovir (6/8), oral valganciclovir (2/8) for six months, along with intravitreal ganciclovir. Visual outcomes were similar for oral and intravenous therapies; poor baseline acuity and macular involvement tend to result in a worse final acuity.

CONCLUSIONS

Swift treatment is vital to ARN management. Our findings emphasize effective treatment strategies' role in visual prognosis.

ABBREVIATIONS

ACV: Acyclovir; BCVA: Best Corrected Visual Acuity; CMV: Cytomegalovirus; EBV: Epstein Barr Virus; FTA-ABS: Fluorescent treponemal antibody absorption test; HSV 1-2: Herpes simplex virus 1-2; HIV: Human Immunodeficiency Virus; IV-ACV: Intravenous- Acyclovir; PCR: Polymerase Chain Reaction;Tg: Toxoplasma gondii; VZV: Varicella Zoster Virus; VCV: Valacyclovir; VDRL: Venereal disease research laboratory test.

Diagnostic and therapeutic challenges in acute retinal necrosis; an update

Acute retinal necrosis (ARN) is a rare but severe ophthalmic pathology defined by panuveitis, retinal necrosis, and high rates of retinal detachment. ARN may lead to poor visual outcomes even if promptly diagnosed and treated. ARN may present with a wide spectrum of clinical findings compatible with panuveitis including anterior uveitis, scleritis, vitritis, necrotizing retinitis, occlusive vasculitis, and optic disc edema. The American Uveitis Society introduced clinical criteria in 1994 for the diagnosis of ARN, while more recent criteria have been proposed by the Standardization of Uveitis Nomenclature (SUN) Working Group and the Japanese ARN Study Group. Multimodal imaging is a valuable tool in evaluating patients with ARN, particularly in unusual cases, while utilizing retinal imaging and applying AI algorithms in these areas of clinical research could be highly beneficial. Over the last few years, significant progress has been made in achieving timely diagnosis and treatment. The precise identification of the viral cause in suspected ARN cases has been greatly enhanced by the advancements in PCR techniques and flow cytometry used for intraocular fluids. systemic (intravenous or oral) antivirals with adjunctive intravitreal antiviral therapy are recommended as first-line therapy to reduce disease severity, the risk of vision loss, and retinal detachment incidence. Although aciclovir was the first existing antiviral agent, at present many clinicians prefer high-dose valaciclovir orally or intravenous aciclovir combined with intravitreal foscarnet. Despite significant progress in diagnosing and treating ARN, further research is needed to improve visual outcomes in this challenging clinical condition.

[Vasculitis of the retina : Clinical aspects, diagnostics, management and treatment]

Inflammatory changes in the retinal vessels can be attributed to a wide range of etiologies. These include infections, intraocular and systemic autoimmune processes, general diseases and iatrogenic factors. As the endothelium of the retinal capillaries forms the inner blood-retinal barrier, a disruption of this structure is directly associated with consequences for the fluid electrolyte balance of the retina. Clinical sequelae can include leakage of the retinal vessels and macular edema, which are often functionally threatening and significantly reduce the quality of life of patients. As the eye can be affected as an "index organ", a work-up of the patient by the ophthalmologist is of great importance. In the age of "precision medicine", efforts are being made to gain new insights into the pathogenetic mechanisms of vasculitis through "omics" in order to develop innovative treatment concepts.

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.

Multitask Deep Learning for Joint Detection of Necrotizing Viral and Noninfectious Retinitis From Common Blood and Serology Test Data

Purpose

Necrotizing viral retinitis is a serious eye infection that requires immediate treatment to prevent permanent vision loss. Uncertain clinical suspicion can result in delayed diagnosis, inappropriate administration of corticosteroids, or repeated intraocular sampling. To quickly and accurately distinguish between viral and noninfectious retinitis, we aimed to develop deep learning (DL) models solely using noninvasive blood test data.

Methods

This cross-sectional study trained DL models using common blood and serology test data from 3080 patients (noninfectious uveitis of the posterior segment [NIU-PS] = 2858, acute retinal necrosis [ARN] = 66, cytomegalovirus [CMV], retinitis = 156). Following the development of separate base DL models for ARN and CMV retinitis, multitask learning (MTL) was employed to enable simultaneous discrimination. Advanced MTL models incorporating adversarial training were used to enhance DL feature extraction from the small, imbalanced data. We evaluated model performance, disease-specific important features, and the causal relationship between DL features and detection results.

Results

The presented models all achieved excellent detection performances, with the adversarial MTL model achieving the highest receiver operating characteristic curves (0.932 for ARN and 0.982 for CMV retinitis). Significant features for ARN detection included varicella-zoster virus (VZV) immunoglobulin M (IgM), herpes simplex virus immunoglobulin G, and neutrophil count, while for CMV retinitis, they encompassed VZV IgM, CMV IgM, and lymphocyte count. The adversarial MTL model exhibited substantial changes in detection outcomes when the key features were contaminated, indicating stronger causality between DL features and detection results.

Conclusions

The adversarial MTL model, using blood test data, may serve as a reliable adjunct for the expedited diagnosis of ARN, CMV retinitis, and NIU-PS simultaneously in real clinical settings.

Progress in the Application of Microneedles in Eye Disorders and the Proposal of the Upgraded Microneedle with Spinule

PURPOSE

In the local administration methods for treating eye diseases, the application of microneedles has great potential due to the shortcomings of low efficacy and significant side effects of local administration preparations. This article provides ideas for the research on the application of ophthalmic microneedle in the treatment of eye diseases.

RESULTS

This article analyzes the physiological structures of the eyes, ocular diseases and its existing ocular preparations in sequence. Finally, this article reviews the development and trends of ocular microneedles in recent years, and summarizes and discusses the drugs of ocular microneedles as well as the future directions of development. At the same time, according to the inspiration of previous work, the concept of "microneedle with spinule" is proposed for the first time, and its advantages and limitations are discussed in the article.

CONCLUSIONS

At present, the application of ocular microneedles still faces multiple challenges. The aspects of auxiliary devices, appearance, the properties of the matrix materials, and preparation technology of ophthalmic microneedle are crucial for their application in the treatment of eye diseases.

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.

Pediatric Posterior Infectious Uveitis

PURPOSE

To describe the most important cause of infectious posterior uveitis in pediatric patients.

METHODS

Review of the literature.

RESULTS

The most important causes of infectious uveitis in pediatric patients are: cat-scratch disease, toxocariasis, tuberculosis, viral diseases and toxoplasmosis. Ocular manifestations include retinitis, neuroretinitis, choroidal granulomas, peripheral granulomas and posterior pole granulomas.

CONCLUSION

Infectious posterior uveitis is a challenging subject and should be considered in the differential diagnosis of any posterior uveitis in children. Infectious uveitis must be excluded before initiating immunosuppressive therapy.

False negative result of polymerase chain reaction in very early stages of acute retinal necrosis

BACKGROUND

Viral nucleic acid testing of intraocular fluid using polymerase chain reaction (PCR) is a major laboratory examination in the diagnosis of acute retinal necrosis (ARN). Importantly, false negative PCR results may occur in several special situations. We reported a case of ARN with a negative PCR result in the aqueous humour in the very early stages of disease.

CASE PRESENTATION

A female patient presented to the ophthalmologist with complaints of blurred vision and redness in her left eye. Her medical history included ARN in her right eye 10 years prior. Although the result of the aqueous viral analysis by PCR in her left eye was negative the first time (one day after the appearance of ocular symptoms), ARN in her left eye was presumed based on the clinical signs. With timely antiviral and anti-inflammatory treatments, the retinal lesions diminished. The viral load of herpes simplex virus (HSV) turned positive (7.25 × 103 copies/mL) one week later, increased to 2.49 × 105 copies/mL after three weeks, and finally turned negative about five weeks after the onset of disease. The initial HSV-IgG level in the aqueous humour was 0.01 U/mL and increased to 222.64 U/mL in the final sampling.

CONCLUSIONS

The results of PCR analysis can be negative in the very early stages of ARN. Diagnosis of ARN should be made based on the clinical features, and antiviral treatments should not be delayed. Repeated PCR analysis of the aqueous humour is necessary to confirm the diagnosis and monitor the disease process.

Clinical association and visual morbidity in uveitis with systemic diseases: An analysis from a tertiary ophthalmic center

AIM

The aim of this study was to identify the incidence, etiology, most common presentations, complications, and the causes of visual loss in posterior uveitis (PU).

MATERIALS AND METHODS

A retrospective study was conducted on a cohort of 125 patients with PU with a minimum follow-up of 6 months. Ocular evaluation consisted of slit-lamp examination, indirect ophthalmoscopy, tonometry, and refraction. Ancillary ophthalmic investigations such as fundus fluorescein angiography, optical coherence tomography, and B-scan ultrasonography were done. Laboratory tests were performed on blood on all patients and in aqueous humor samples obtained by anterior chamber paracentesis in cases of diagnostic dilemmas. All the data were analyzed using SPSS program.

RESULTS

PU occurred in 61%. Infections were noted in 34% and autoimmune diseases in 27%. The most frequent presentation was choroiditis. The most common etiologies were tubercular uveitis in 50%, Toxoplasma retinochoroiditis in 23%, and autoimmune category of serpiginous choroiditis in 56% of patients. Complications occurred in 27% and were most commonly cystoid macular edema and macular scarring. Polymerase chain reaction (PCR), nested PCR, and real-time PCR on ocular fluids were required for diagnosis in 30%. A combination of laboratory investigations on blood and aqueous humor samples were confirmation in 88%.

CONCLUSION

PU and its sequelae are known to be sight threatening and are associated with systemic diseases. They have diverse etiologies and presentations. Identification of etiology is important as management is diametrically opposite in infections and autoimmune diseases.

Posterior Herpetic Uveitis: A Comprehensive Review

PURPOSE

To report and illustrate the main clinical presentations of posterior herpetic uveitis.

METHODS

Narrative review.

RESULTS

The ocular manifestations of posterior herpetic uveitis include different clinical presentations. Herpes simplex and varicella zoster can cause acute retinal necrosis, progressive outer retinal necrosis, and non-necrotizing herpetic retinopathies. Cytomegalovirus has been associated with fulminant retinitis with confluent areas of retinal necrosis and retinal hemorrhages, indolent/granular retinitis, and frosted branch angiitis. These diverse clinical presentations are often associated with specific risk factors and different immunological profiles of the host.

CONCLUSIONS

Herpetic viruses can cause posterior uveitis, presenting various clinical findings. Specific ocular manifestations and the immunological status of the host can help to differentiate the various herpetic entities before laboratory tests confirm the diagnosis.

Cytomegalovirus anterior uveitis and occlusive retinal vasculitis without retinitis in a patient on immunomodulatory therapy

PURPOSE

To describe unusual clinical features and therapeutic management of a case of cytomegalovirus (CMV) ocular disease in a patient on immunomodulatory therapy.

SETTING/VENUE

Moorfields Eye Hospital NHS Foundation Trust, London, UK.

METHODS

Medical history, clinical findings, investigation results, and multimodal imaging were retrospectively collected.

RESULTS

A 61-year-old, South-East Asian man, developed CMV-related endotheliitis and occlusive retinal vasculitis, diagnosed by wide-angle fluorescein angiography. No retinitis was present on the fundus examination. Suspicion of CMV etiology was based on anterior segment findings, especially the presence of coin-shaped endothelial lesions. The diagnosis was confirmed by aqueous polymerase chain reaction (PCR) analysis which was positive for CMV DNA. The combined use of topical and systemic valganciclovir resulted in significant improvement of the picture.

CONCLUSIONS

CMV can manifest in the eye as occlusive retinal vasculitis without the presence of typical retinitis.

Inflammatory eye disease for rheumatologists

PURPOSE OF REVIEW

This review provides a framework for understanding inflammatory eye disease diagnosis, differential diagnosis, and management for rheumatologists. Uveitis, scleritis, episcleritis, peripheral ulcerative keratitis, and orbital inflammation are all discussed. The goal is to facilitate the development of approaches to inflammatory eye diseases that will help rheumatologists co-manage these patients with eye care providers specializing in ocular inflammation.

RECENT FINDINGS

In recent years, studies have aimed to advance biologic treatments and define standard-of-care therapy. Inflammatory eye diseases are highly heterogeneous and often rare, which poses significant challenges to their research and the interpretation of existing data. To date, glucocorticoids, mycophenolate, methotrexate, and TNF inhibitors remain the mainstay of treatment options for many of these diseases.

SUMMARY

Patients with inflammatory eye diseases require multidisciplinary care for best outcomes, frequently including rheumatologists. Understanding the differentials, diagnostics, and treatment are essential to preserving vision in these patients. The diverse nature of the disease processes within this field requires focusing on specific disease phenotypes and endotypes in research and clinical practice.

Infrared analysis in the aqueous humor of patients with uveitis: Preliminary results

Inflammatory processes affecting the uvea result in a temporary o permanent blurred vision and represent an important cause of visual impairment worldwide. It is often hard to make a precise diagnosis which is dependent on the clinical expertise, diagnostic tests, laboratory investigations in blood and sometimes in the aqueous humor (AH). With the aim of obtaining proof of principle Fourier Transformed Infrared (FT-IR) absorbance spectroscopy was applied to study the molecular composition of 72 AH samples collected in 26 patients with uveitis and in 44 controls. The unsupervised exploration of the internal structure of the dataset by principal component analysis reduced hundreds IR variables to those most representative allowing to obtain the predictive model that distinguished the AH spectra of patients with uveitis from controls. The same result was obtained by unsupervised agglomerative cluster analysis. After labeling the spectra with some clinical information it was observed that most severe uveitis with active processes were grouped separately from chronic and relapsing uveitis and controls. The consistence of prediction models is discussed in the light of supporting etiological diagnosis by machine learning processes. In conclusion, proof of principle has been obtained that the IR spectral pattern of AH may reflect particular uveal diseases.

Human immunodeficiency virus retinopathy with presumed cytomegalovirus retinitis with macular oedema in a diabetic

A man in his early 50s on regular follow-up for a stable non-proliferative diabetic retinopathy (NPDR) presented with decreased vision, worsening of retinal pathology and macular oedema in both eyes. His corrected distance visual acuity (CDVA) was 6/9 in the right eye and 6/15 in the left eye and fundus examination showed multiple intraretinal haemorrhages in all quadrants. His systemic workup revealed a severe thrombocytopaenia, which prompted a further detailed systemic evaluation revealing him to be positive for HIV with retinopathy complicating the pre-existing NPDR. Given the significant inflammation and macular oedema, a cocktail of intravitreal bevacizumab, ganciclovir and dexamethasone was administered. The retinopathy and macular oedema resolved and the CDVA improved to 6/6 in both eyes over a 6-month follow-up period. Any sudden worsening of fundus findings in a patient with diabetes necessitates immediate and detailed ocular and systemic evaluation, especially when the immune status is unknown.

An update on immunological and molecular tests and their impact in infectious uveitis

Early diagnosis of infectious uveitis can lead to prompt initiation of treatment to minimize vision-threatening sequelae. As various infectious etiologies of uveitis share similar clinical features, advancements in polymerase chain reaction (PCR) and metagenomic next-generation sequencing (MDS) have shown significant promise in improving diagnostic capabilities. Various techniques of PCR, including real-time, multiplex, comprehensive, and broad-range, have increased the armamentarium for infectious uveitis diagnosis. Additionally, metagenomic deep sequencing technology has provided a methodology to identify causative pathogens as well as novel etiologies of uveitis. This review discusses the diagnostic tools available for infectious uveitis and highlights the advantages and disadvantages of the techniques.

Unilateral Acute Idiopathic Maculopathy following Severe Acute Respiratory Syndrome Corona Virus (SARS-CoV-2) Infection

AIM

To report a case of unilateral acute idiopathic maculopathy (UAIM) following SARS-CoV-2 virus infection.

CASE DESCRIPTION

A 44-year-old male patient, infected with SARS-CoV-2 virus previously, presented to the retina department with complaints of sudden blurring of vision in right eye. His presenting visual acuity in right eye was 20/30, N8. Fundus showed an irregular area of yellowish-white subretinal lesion at the macula involving the fovea with reddish-brown pigment clumps. Retinal imaging findings were consistent with the diagnosis of UAIM. No treatment was given.

RESULTS

The imaging findings showed improvement at day 7 post-presentation with improvement in vision to 20/20, N6. At final visit (5-week post presentation), visual acuity was maintained at 20/20, N6 and there was no recurrence of findings.

EXPERT OPINION

Unilateral acute idiopathic maculopathy might be associated with SARS-CoV-2 virus infection.

CONCLUSION

Infection with SARS-CoV-2 virus might be associated with UAIM. Such an association has not yet been described in the literature.

Stepwise approach for fundus imaging in the diagnosis and management of posterior uveitis

An array of retinochoroid imaging modalities aid in comprehensive evaluation of the immunopathological changes in the retina and choroid, forming the core component for the diagnosis and management of inflammatory disorders such as uveitis. The recent technological breakthroughs have led to the development of imaging platforms that can evaluate the layers of retina and choroid and the structural and functional alteration in these tissues. Ophthalmologists heavily rely on imaging modalities such as dye-based angiographies (fluorescein angiography and indocyanine green angiography), optical coherence tomography, fundus autofluorescence, as well as dye-less angiography such as optical coherence tomography angiograph,y for establishing a precise diagnosis and understanding the pathophysiology of the diseases. Furthermore, these tools are now being deployed with a 'multimodal' approach for swift and accurate diagnosis. In this comprehensive review, we outline the imaging platforms used for evaluation of posterior uveitis and discuss the organized, algorithmic approach for the assessment of the disorders. Additionally, we provide an insight into disease-specific characteristic pathological changes and the established strategies to rule out disorders with overlapping features on imaging.

Adaptive Optics of Kyrieleis Plaques in Varicella Zoster Virus-Associated Posterior Uveitis: A Multimodal Imaging Analysis

Kyrieleis plaques (KP) represent a peculiar type of vasculitis affecting retinal arterial branches in a beaded segmental pattern that can be found in several posterior inflammatory ocular conditions. The nature and precise location of KP is unclear. Adaptive Optics (AO) provides an in vivo visualization of retinal vasculature on a microscopic level, thus permitting a more detailed characterization of KP as compared to traditional imaging techniques. This study aims to report AO imaging of KP in Varicella Zoster virus (VZV)-associated posterior uveitis and to correlate the findings with traditional imaging techniques. Three patients diagnosed with VZV posterior uveitis underwent adaptive optics (AO) imaging and traditional multimodal imaging techniques, including fundus photography, fluorescein angiography, indocyanine green angiography and optical coherence tomography. In all subjects, AO imaging revealed segmental hyporeflectivity confined to the vessel wall, with no evidence of arterial wall disruption or extravascular involvement. In our series, AO findings support the view that KP are localized within the inner arterial wall, possibly at the endothelial level.

Application of metagenomic next-generation sequencing in suspected intraocular infections

PURPOSE

To evaluate the efficacy of metagenomic next-generation sequencing (mNGS) and to explore its value in the diagnosis of intraocular infection.

METHODS

A retrospective case-series study of patients with suspected intraocular infection was performed. Intraocular fluid samples were collected from all the patients and sent for mNGS. Detailed clinical data, the results of mNGS and other laboratory examinations, the sequencing data of mNGS, and the final diagnosis were recorded.

RESULTS

Fifteen eyes of 15 patients were included in the study. Eight samples were identified as positive for different kinds of pathogens by mNGS, which were all confirmed by other laboratory examinations or effective diagnostic treatment. The mNGS results were negative in seven samples. The final diagnosis was still intraocular infection in four of the seven negative results. Of these, one patient was diagnosed with fungal endophthalmitis according to the clinical characteristics and good treatment response to the anti-fungal therapy, one patient underwent vitrectomy and the bacterial culture of the vitreous sample was positive for Brucella melitensis, and two patients were diagnosed with ocular tuberculosis according to the positive T-SPOT test and effective anti-tuberculous treatments.

CONCLUSIONS

mNGS could be helpful in determining pathogens in cases of suspected intraocular infection. The mNGS protocols should be optimized for the detection of intracellular bacterial and fungal pathogens.

Improved Detection of Herpesviruses from Diluted Vitreous Specimens Using Hydrogel Particles

Infectious uveitis is a sight-threatening infection commonly caused by herpesviruses. Vitreous humor is often collected for molecular confirmation of the causative agent during vitrectomy and mixed in large volumes of buffered saline, diluting the pathogen load. Here, we explore affinity-capture hydrogel particles (Nanotrap®) to concentrate low abundant herpesviruses from diluted vitreous. Simulated samples were prepared using porcine vitreous spiked with HSV-1, HSV-2, VZV and CMV at 105 copies/mL. Pure undiluted samples were used to test capturing capability of three custom Nanotrap particles (red, white and blue) in a vitreous matrix. We found that all particles demonstrated affinity to the herpesviruses, with the Red Particles having both good capture capability and ease of handling for all herpesviruses. To mimic diluted vitrectomy specimens, simulated-infected vitreous were then serially diluted in 7 mL TE buffer. Diluted samples were subjected to an enrichment protocol using the Nanotrap Red particles. Sensitivity of pathogen detection by qPCR in diluted vitreous increased anywhere between 2.3 to 26.5 times compared to non-enriched specimens. This resulted in a 10-fold increase in the limit of detection for HSV-1, HSV-2 and VZV. These data demonstrated that Nanotrap particles can capture and concentrate HSV-1, HSV-2, VZV and CMV in a vitreous matrix.

Viral Infection and Antiviral Treatments in Ocular Pathologies

Ocular viral infections are common and widespread globally. These infectious diseases are a major cause of acute red eyes and vision loss. The eye and its nearby tissues can be infected by several viral agents, causing infections with a short course and limited ocular implications or a long clinical progression and serious consequences for the function and structure of the ocular region. Several surveillance studies underline the increased emergence of drug resistance among pathogenic viral strains, limiting treatment options for these infections. Currently, in the event of resistant infections, topical or systemic corticosteroids are useful in the management of associated immune reactions in the eye, which contribute to ocular dysfunction. Many cases of viral eye infections are misdiagnosed as being of bacterial origin. In these cases, therapy begins late and is not targeted at the actual cause of the infection, often leading to severe ocular compromises, such as corneal infiltrates, conjunctival scarring, and reduced visual acuity. The present study aims at a better understanding of the viral pathogens that cause eye infections, along with the treatment options available.

Clinical Features and Multimodal Imaging in Atypical Posterior Uveitis Secondary to Bartonella Henselae Infection

PURPOSE

To characterize an unusual presentation of infectious posterior uveitis using multimodal imaging, and discuss the clinical decision-making involved in diagnosis and treatment.

METHODS

Wide-field fundus photography, swept-source optical coherence tomography (OCT), swept-source OCT angiography, fluorescein angiography, and indocyanine green angiography.

RESULTS

This patient presented with cyclical fevers and blurry vision. Fundus examination revealed bilateral optic disc edema, macular intraretinal white spots and many scattered yellow-white chorioretinal lesions. Multimodal imaging characteristics suggested that many of these lesions represent choroidal granulomas. Extensive systemic workup was only notable for borderline elevated Bartonella henselae IgG titers (1:128), however convalescent IgG titers were elevated at 38 days (1:512) supporting the diagnosis of Bartonella chorioretinitis.

CONCLUSION

Ocular manifestations of Bartonella henselae infection are varied and may include choroidal granulomas. Multimodal imaging characteristics may help identify etiologies of infectious uveitis. Convalescent titers are important when evaluating patients with suspected Bartonellosis, especially patients with atypical presentations.

Advances in the microbiological diagnosis of herpetic retinitis

Viral retinitis associated with herpesvirus is one of the most severe forms of uveitis and is a potentially sight-threatening ophthalmologic disease. The prognosis is poor and a rapid and aggressive management is necessary to improve the visual and sometimes vital prognosis of these patients. The treatments used are not without side effects, while many differential diagnoses exist, such as toxoplasmic retinochoroiditis, syphilitic retinitis, endogenous endophthalmitis and intraocular lymphoma. Causatives viruses are herpes simplex virus, varicella-zoster virus, and cytomegalovirus, which require rapid detection in ocular fluid, mainly aqueous humor. However, only a small amount of intraocular fluid is available for analysis. Advances in microbiological diagnostic techniques therefore were key factors in improving the management of these diseases. Historically, the diagnosis was based on immunological tests but more recently advances in molecular biology, in particular polymerase chain reaction, have played a crucial role to obtain a reliable and rapid diagnosis of viral retinitis associated with herpesvirus, as discussed in this review.

Are Viral Infections Key Inducers of Autoimmune Diseases? Focus on Epstein–Barr Virus

It is generally accepted that certain viral infections can trigger the development of autoimmune diseases. However, the exact mechanisms by which these viruses induce autoimmunity are still not understood. In this review, we first describe hypothetical mechanisms by which viruses induce some representative autoimmune diseases. Then, we focus on Epstein–Barr virus (EBV) and discuss its role in the pathogenesis of rheumatoid arthritis (RA). The discussion is mainly based on our own previous findings that (A) EBV DNA and its products EBV-encoded small RNA (EBER) and latent membrane protein 1 (LMP1) are present in the synovial lesions of RA, (B) mRNA expression of the signaling lymphocytic activation molecule-associated protein (SAP)/SH2D1A gene that plays a critical role in cellular immune responses to EBV is reduced in the peripheral T cells of patients with RA, and (C) EBV infection of mice reconstituted with human immune system components (humanized mice) induced erosive arthritis that is pathologically similar to RA. Additionally, environmental factors may contribute to EBV reactivation as follows: Porphyromonas gingivalis peptidylarginine deiminase (PAD), an enzyme required for citrullination, engenders antigens leading to the production of citrullinated peptides both in the gingiva and synovium. Anti-citrullinated peptides autoantibody is an important marker for diagnosis and disease activity of RA. These findings, as well as various results obtained by other researchers, strongly suggest that EBV is directly involved in the pathogenesis of RA, a typical autoimmune disease.

Triamcinolone acetonide injectable suspension for suprachoroidal use in the treatment of macular edema associated with uveitis

Introduction

Macular edema due to noninfectious uveitis is a sight-threatening complication that is routinely treated with corticosteroids. Triamcinolone acetonide injectable suspension for suprachoroidal use (Xipere™) is an alternative treatment option for patients with non-infectious uveitis associated macular edema.

Areas covered

This review describes the recently FDA approved triamcinolone acetonide injectable suspension that can be injected into the suprachoroidal space. This physiological space is between the sclera and choroid. This allows for therapeutic targeting of the retina and choroid. This review highlights published clinical trials for this novel drug preparation.

Expert opinion

Suprachoroidal administration of triamcinolone acetonide has shown improvement in vision and inflammation in studies with non-infectious uveitis associated macular edema. This unique delivery method suggests the potential to decrease side effects of anterior segment exposure such as glaucoma and cataract, but head-to-head trials are needed for further study of safety and efficacy. Additionally, there are promising prospective studies underway for utilization of the suprachoroidal space for other diseases including macular degeneration, diabetic macular edema, and ocular tumors.

Automated detection of retinal exudates and drusen in ultra-widefield fundus images based on deep learning

BACKGROUND

Retinal exudates and/or drusen (RED) can be signs of many fundus diseases that can lead to irreversible vision loss. Early detection and treatment of these diseases are critical for improving vision prognosis. However, manual RED screening on a large scale is time-consuming and labour-intensive. Here, we aim to develop and assess a deep learning system for automated detection of RED using ultra-widefield fundus (UWF) images.

METHODS

A total of 26,409 UWF images from 14,994 subjects were used to develop and evaluate the deep learning system. The Zhongshan Ophthalmic Center (ZOC) dataset was selected to compare the performance of the system to that of retina specialists in RED detection. The saliency map visualization technique was used to understand which areas in the UWF image had the most influence on our deep learning system when detecting RED.

RESULTS

The system for RED detection achieved areas under the receiver operating characteristic curve of 0.994 (95% confidence interval [CI]: 0.991-0.996), 0.972 (95% CI: 0.957-0.984), and 0.988 (95% CI: 0.983-0.992) in three independent datasets. The performance of the system in the ZOC dataset was comparable to that of an experienced retina specialist. Regions of RED were highlighted by saliency maps in UWF images.

CONCLUSIONS

Our deep learning system is reliable in the automated detection of RED in UWF images. As a screening tool, our system may promote the early diagnosis and management of RED-related fundus diseases.

Retinal Proteomic Analysis in a Mouse Model of Endotoxin-Induced Uveitis Using Data-Independent Acquisition-Based Mass Spectrometry

Uveitis is a group of sight-threatening ocular inflammatory diseases, potentially leading to permanent vision loss in patients. However, it remains largely unknown how uveitis causes retinal malfunction and vision loss. Endotoxin-induced uveitis (EIU) in rodents is a good animal model to study uveitis and associated acute retinal inflammation. To understand the pathogenic mechanism of uveitis and screen potential targets for treatment, we analyzed the retinal proteomic profile of the EIU mouse model using a data-independent acquisition-based mass spectrometry (SWATH-MS). After systemic LPS administration, we observed activation of microglial cells accompanied with the elevation of pro-inflammatory mediators and visual function declines. In total, we observed 79 upregulated and 90 downregulated differentially expressed proteins (DEPs). Among the DEPs, we found that histone family members (histone H1, H2A, H2B) and blood proteins including haptoglobin (HP), hemopexin (HPX), and fibrinogen gamma chain (FGG) were dramatically increased in EIU groups relative to those in control groups. We identified phototransduction and synaptic vesicle cycle as the top two significant KEGG pathways. Moreover, canonical pathway analysis on DEPs using Ingenuity Pathway Analysis revealed top three most significant enriched pathways related to acute phase response signaling, synaptogenesis signaling, and eif2 signaling. We further confirmed upregulation of several DEPs associated with the acute phase response signaling including HP, HPX, and FGG in LPS-treated retinas by qPCR and Western blot. In summary, this study serves as the first report to detect retinal proteome changes in the EIU model. The study provides several potential candidates for exploring the mechanism and novel therapeutic targets for uveitis and other retinal inflammatory diseases.

The Role of Optical Coherence Tomography and Optical Coherence Tomography Angiography in the Differential Diagnosis of Posterior Uveitis

PURPOSE

Modalities such as optical coherence tomography (OCT) and OCT angiography (OCTA) have improved the diagnostic utility of fundus imaging in management of uveitis. The purpose of this study is to review role of OCT and OCTA in differential diagnosis of certain posterior uveitic entities.

METHODS

Narrative review.

RESULTS

In this review, we have comprehensively summarized the utility of OCT and OCTA in helping the clinician diagnose common but challenging inflammatory conditions including ocular toxoplasmosis, viral retinitis, and vitreoretinal lymphoma, among others. OCT and OCTA can also be used to assess the choriocapillaris involvement in conditions such as multiple evanescent white dot syndrome, and choroidal granulomas in tubercular and sarcoid uveitis.

CONCLUSIONS

Fundus imaging with OCT and OCTA has assumed a significant role in establishing the diagnosis in uveitis apart from microbiological and other laboratory analysis. Advantages such as rapidity and non-invasiveness make these imaging modalities very useful and convenient.

A case of non-necrotising herpetic retinitis

In developed countries, the main etiology of posterior uveitis is of infectious origin, Herpes is the most common viral agent as it has a wide spectral of ocular manifestations. These manifestations could depend on the patient's immunologic state, ranging from a mild focal form of non-necrotizing herpetic renitis (NNHR) to a severe form of Acute retinal necrosis (ARN). We present a case of NNHR by VHS 2 and the different differential diagnostics previous to its diagnosis: atypical ocular toxoplasmosis, ocular tuberculosis and ARN. During its evolution, it presented a drastic drop in the visual acuity despite of the antiviral treatment, and with systemic corticoids and the injury's clinical improvement. This event led to reevaluate the suspected entities, establishing the NNHR as a definitive diagnostic by exclusion that constituted a challenging diagnostic.

A Comprehensive Update on Retinal Vasculitis: Etiologies, Manifestations and Treatments

Retinal vasculitis is characterized by inflammatory involvement of retinal arterioles, venules and/or capillaries and can be associated with a myriad of systemic and ophthalmic diseases. In this review, we have comprehensively discussed the etiologies, clinical manifestations, and presentations of retinal vasculitis. We have also included newer advances in imaging in retinal vasculitis such as OCTA and widefield imaging.

Ocular Manifestations of Chikungunya Infection: A Systematic Review

The Chikungunya virus (CHIKV) can cause long lasting symptoms and manifestations. However, there is little information on which ocular ones are most frequent following infection. We performed a systematic review (registered in the International Prospective Register of Systematic Reviews; no CRD42020171928) to establish the most frequent ocular manifestations of CHIKV infection and their associations with gender and age. Articles published until September 2020 were selected from PubMed, Scielo, Cochrane and Scopus databases. Only studies with CHIKV-infected patients and eye alterations were included. Reviews, descriptive studies, or those not investigating the human ocular manifestations of CHIKV, those with patients with other diseases and infections, abstracts and studies without relevant data were excluded. Twenty-five studies were selected for inclusion. Their risk of bias was evaluated by a modified Newcastle-Ottawa scale. The most frequent ocular symptoms of CHIKV infection included ocular pain, inflammation and reduced visual acuity, whilst conjunctivitis and optic neuritis were the most common manifestations of the disease. These occurred mostly in individuals of 42 ± 9.5 years of age and woman. The few available reports on CHIKV-induced eye manifestations highlight the need for further research in the field to gather more substantial evidence linking CHIKV infection, the eye and age/gender. Nonetheless, the data emphasizes that ocular alterations are meaningful occurrences of CHIKV infection which can substantially affect quality of life.

Immune Privilege Furnishes a Niche for Latent Infection

The microenvironment of the CNS (eye and brain) is fertile ground for infection if the barriers are breached. The result of pathogen invasion is often devastating destruction of tissues. In the eye, inflammation is broadly classified either as "infectious" (i.e. caused by infection) or "non-infectious". However, increasingly, forms of intraocular inflammation (IOI), which clinically appear to be "non-infectious" turn out to be initiated by infectious agents, suggesting that pathogens have been retained in latent or persistent form within ocular tissues and have reactivated to cause overt disease. A similar pathogenesis applies to latent infections in the brain. Not all CNS tissues provide an equally protective niche while different pathogens escape detection using different strategies. This review summarises how immune privilege (IP) in the CNS may be permissive for latent infection and allow the eye and the brain to act as a reservoir of pathogens which often remain undetected for the lifetime of the host but in states of immune deficiency may be activated to cause sight- and life-threatening inflammation.

SELF-INFLICTED LASER-INDUCED MACULOPATHY MASQUERADING AS POSTERIOR UVEITIS IN A PATIENT WITH SUSPECTED IgG4-RELATED DISEASE

PURPOSE

To report the clinical presentation and imaging features in a case of bilateral self-inflicted handheld laser-induced maculopathy which masqueraded as progressive posterior uveitis in a patient with suspected IgG4-related disease.

METHODS

Case report with clinical history, fundus photographs, fluorescein angiography, indocyanine green angiography, and swept-source optical coherence tomography.

RESULTS

A young Asian Indian man presented with sudden progressive bilateral visual loss over the past 1 week. He was being treated with oral corticosteroids for multiple subcutaneous skin lesions believed to be due to IgG4-related disease. Findings included bilateral central areas of outer retinal disruption with eccentric linear and serpentine lesions showing hypoautofluorescence. Hyperreflective bands extending from the retinal pigment epithelium and interdigitation zone to the outer plexiform layer were present on swept-source optical coherence tomography. After careful history and evaluation of multimodal imaging, posterior uveitis was excluded, and a diagnosis of handheld laser-induced maculopathy was established.

CONCLUSION

Pattern recognition is important in establishing a diagnosis of self-inflicted handheld laser-induced maculopathy which can masquerade as posterior uveitis. Increasing availability of powerful Class IIIb laser devices in both developed and developing countries will likely increase the incidence of this entity.

A review of diseases of the retina for neurologists

Diseases of the retina are common and numerous, with causes ranging over inherited, inflammatory, vascular, infectious, neoplastic, traumatic, toxic, and idiopathic etiologies. A key issue in the diagnosis of retinal disease is the duration of symptoms, which can be acute, chronic, or acute presentations of chronic disease. Clinical examination with direct ophthalmoscopy or, even better, biomicroscopy with a slit lamp and condensing lens, is a key component of diagnosis, which can be enhanced through investigational methods such as fluorescein angiography, optical coherence tomography, or electroretinography. Consideration of the history, visual acuity and visual field, and fundoscopic findings is usually sufficient to determine whether patients need referral on an emergency, urgent, or routine basis. Emphasis is given to vascular disease, age-related macular degeneration, diabetic retinopathy, genetic eye disease, and retinal detachment.

Povidone-Iodine Attenuates Viral Replication in Ocular Cells: Implications for Ocular Transmission of RNA Viruses

Several RNA viruses, including SARS-CoV-2, can infect or use the eye as an entry portal to cause ocular or systemic diseases. Povidone-Iodine (PVP-I) is routinely used during ocular surgeries and eye banking as a cost-effective disinfectant due to its broad-spectrum antimicrobial activity, including against viruses. However, whether PVP-I can exert antiviral activities in virus-infected cells remains elusive. In this study, using Zika (ZIKV) and Chikungunya (CHIKV) virus infection of human corneal and retinal pigment epithelial cells, we report antiviral mechanisms of PVP-I. Our data showed that PVP-I, even at the lowest concentration (0.01%), drastically reduced viral replication in corneal and retinal cells without causing cellular toxicity. Antiviral effects of PVP-I against ZIKV and CHIKV were mediated by direct viral inactivation, thus attenuating the ability of the virus to infect host cells. Moreover, one-minute PVP-I exposure of infected ocular cells drastically reduced viral replication and the production of infectious progeny virions. Furthermore, viral-induced (CHIKV) expression of inflammatory genes (TNF-α, IL-6, IL-8, and IL1β) were markedly reduced in PVP-I treated corneal epithelial cells. Together, our results demonstrate potent antiviral effects of PVP-I against ZIKV and CHIKV infection of ocular cells. Thus, a low dose of PVP-I can be used during tissue harvesting for corneal transplants to prevent potential transmission of RNA viruses via infected cells.

Flow cytometric analysis of T lymphocytes and cytokines in aqueous humor of patients with varicella zoster virus-mediated acute retinal necrosis

BACKGROUND

The purpose of this study is to investigate the aqueous humor (AH) T lymphocyte subsets and cytokines of acute retinal necrosis (ARN) to elucidate the immunologic inflammatory features of this disorder.

METHODS

Three patients with ARN infected with varicella zoster virus (VZV) who underwent multiple intravitreal injections of ganciclovir were enrolled in this study. The control group consisted of four non-infectious patients with acute anterior uveitis (AAU). Flow cytometric analysis was performed on the lymphocyte subsets from the AH and peripheral blood (PB) samples during the active phase of intraocular inflammation. Five inflammatory cytokines were measured in each AH sample and various clinical characteristics were also assessed.

RESULTS

VZV deoxyribonucleic acid (DNA) was detected by real-time polymerase chain reaction (PCR) in AH from all the ARN patients, who showed higher CD8+ T lymphocytes population in AH than the AAU patients (p = 0.006). CD4/CD8 ratios of T lymphocytes and the percentage of CD8 + CD25+ T lymphocytes in AH were significantly lower in ARN than in AAU (p = 0.006; p = 0.012). In the ARN patients, the percentages of CD4+ and CD8+ T lymphocytes in AH were higher than those found in PB. The percentage of CD4 + CD25+ T lymphocytes in AH was significantly higher than the proportion in PB in the AAU patients (p = 0.001). Immunoregulatory cytokine Interleukin-10 in AH was significantly elevated in the ARN patients in comparison with the case of the AAU patients (p = 0.036). In ARN, the copy number of VZV DNA in AH positively correlated with the percentage of CD8+ T lymphocytes in AH and negatively correlated with the CD4/CD8 ratio in AH during the course of disease treatment (p = 0.009, r = 0.92; p = 0.039, r = - 0.834).

CONCLUSION

The ARN patients caused by VZV had different intraocular T lymphocyte subsets and cytokines profile than those of the non-infectious patients. High percentages of CD8+ T lymphocytes and low CD4/CD8 T cell ratios may be a potential biomarker for diagnosis of viral-infectious uveitis. T lymphocytes examination at the inflammatory sites has the potential to become a useful research tool for differentiating viral and non-viral uveitis.

Patterns of cytomegalovirus retinitis at a tertiary referral center in Turkey

PURPOSE

To analyze predisposing conditions in Turkish patients with CMV retinitis and to compare HIV-positive and HIV-negative patients.

METHODS

We reviewed medical charts and ocular images of 41 patients with CMV retinitis diagnosed between 1996 and 2019.

RESULTS

Eleven patients (27%) had HIV infection and 30 were immunocompromised from diverse causes. Initial visual acuity, type, zone, and extent of CMV retinitis, and response to anti-CMV treatment were not significantly different between the two groups. Vitreous haze and panretinal occlusive vasculopathy were the presenting features only in non-HIV patients, seen in 34% and 16% of eyes, respectively. Although not statistically significant, recurrent CMV retinitis was more common in non-HIV patients (17.4% vs. 4.3%/eye-year) and immune recovery uveitis was more common in HIV patients (43% vs. 26%/eye-year). Visual outcomes were similar. Final visual acuity of 1 logMAR or worse was significantly associated with the recurrence of CMV retinitis (odds ratio 9.67; p = 0.01) and also with the occurrence of immune recovery uveitis (odds ratio 4.31; p = 0.058).

CONCLUSIONS

Diverse immunocompromising conditions are more commonly associated with CMV retinitis than HIV infection in Turkish patients. Intraocular inflammation was more commonly associated with active retinitis in non-HIV patients and immune recovery uveitis was more common in HIV patients.

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.

Association Between Air Pollution and the Risk of Uveitis: A Nationwide, Population-Based Cohort Study

Previous studies have revealed an association between ocular surface disorders and air pollution, few studies have focused on the risk of uveitis. We aimed to investigate whether air pollution increases the risk of uveitis. We used the Taiwan Longitudinal Health Insurance Database (LHID) and the Taiwan Air Quality Monitoring Database (TAQMD) to conduct a retrospective cohort study. Air pollutant concentrations, including those of carbon dioxide (CO₂), were grouped into four levels according to quartiles. The outcome was the incidence of uveitis, as defined in the International Classification of Diseases, Ninth Revision. We used univariable and multivariable Cox proportional hazard regression models to calculate the adjusted hazard ratios (aHRs) and determine the potential risk factors of uveitis. Overall, 175,489 subjects were linked to their nearby air quality monitoring stations. We found that for carbon monoxide, the aHRs of uveitis risk for the Q3 and Q4 levels were 1.41 (95% confidence interval (CI) = 1.23–1.61) and 2.19 (95% CI = 1.93–2.47), respectively, in comparison with those for the Q1 level. For nitric oxide, the aHRs for the Q3 and Q4 levels were 1.46 (95% CI = 1.27–1.67) and 2.05 (95% CI = 1.81–2.32), respectively. For nitrogen oxide (NOx), the aHRs for the Q2, Q3, and Q4 levels were 1.27 (95% CI = 1.11–1.44), 1.34 (95% CI = 1.16–1.53), and 1.85 (95% CI = 1.63–2.09), respectively. For total hydrocarbon (THC), the aHRs for the Q2, Q3, and Q4 levels were 1.42 (95% CI = 1.15–1.75), 3.80 (95% CI = 3.16–4.57), and 5.02 (95% CI = 4.19–6.02), respectively. For methane (CH4), the aHRs for the Q3 and Q4 levels were 1.94 (95% CI = 1.60–2.34) and 7.14 (95% CI = 6.01–8.48), respectively. In conclusion, air pollution was significantly associated with incidental uveitis, especially at high THC and CH₄ levels. Furthermore, the uveitis risk appeared to increase with increasing NOx and THC levels.

Response to "Comment On: Acute Retinal Necrosis: Is the Current Valacyclovir Regimen Adequate?"

Acute Retinal Necrosis (ARN) is a potentially devastating form of Uveitis. Antivirals are the mainstay treatment for this syndrome. In this letter, we question the current oral Valacyclovir dosage, based on the experience we had with a recent unresponsive ARN case.

A case of non-necrotising herpetic retinitis

In developed countries, the main origin of posterior uveitis is an infection. Herpes is the most common viral agent, as it has a wide spectrum of ocular manifestations. These manifestations may depend on the immunological state of the patient, and range from a mild focal form of non - necrotising herpetic retinitis (NNHR) to a severe form of acute retinal necrosis (ARN). A case of NNHR due to Herpes simplex virus type 2 (HSV-2) is reported, along with the different differential diagnostics prior to its diagnosis: atypical ocular toxoplasmosis, ocular tuberculosis, and ARN. During its course, despite the antiviral treatment, systemic corticoids and the clinical improvement of the injury, there was a drastic drop in the visual acuity. This event led to the re-evaluation of the suspected entities, establishing the NNHR as a definitive diagnostic by exclusion, which was a diagnostic challenge.

Rational laboratory testing in uveitis: A Bayesian analysis

Uveitis encompasses a heterogeneous group of clinical entities with the common feature of intraocular inflammation. In addition to patient history and examination, a focused set of laboratory investigations is frequently necessary to establish a specific diagnosis. There is limited consensus among uveitis specialists regarding appropriate laboratory evaluation for many distinct patient presentations. The appropriateness of a laboratory test for a given case of uveitis will depend on patient-specific as well as epidemiologic factors. Bayesian analysis is a widely used framework for the interpretation of laboratory testing, but is seldom adhered to in clinical practice. Bayes theorem states that the predictive value of a particular laboratory test depends on the sensitivity and specificity of that test, as well as the prevalence of disease in the population being tested. In this review we will summarize the performance of commonly-utilized laboratory tests for uveitis, as well as the prevalence of uveitic diagnoses in different geographic practice settings. We will propose a logical framework for effective laboratory testing in uveitic disease through rigorous application of Bayesian analysis. Finally, we will demonstrate that while many highly sensitive laboratory tests offer an effective means to rule out associated systemic disease, limited test specificity and low pretest probability often preclude the diagnosis of systemic disease association with any high degree of certainty, even in the face of positive testing.