Infectious Uveitis

A Single-Center Case Series of Acute Retinal Necrosis at Teikyo University: Clinical Characteristics and Treatment Outcomes

Aim To evaluate the clinical characteristics, treatment course, and prognosis of patients with acute retinal necrosis (ARN), which can rapidly progress and cause severe vision loss. Design Single-center retrospective case series. Subjects and methods Six patients and seven eyes diagnosed with ARN at Teikyo University Hospital were included in this study. The clinical presentation and treatment prognosis were investigated based on data obtained from medical records. Results The mean age of the patients at the initial diagnosis was 63.6 years. Although the mean Logarithm of the Minimum Angle of Resolution (LogMAR) visual acuity tended to decrease from 0.77 at the first visit to 1.29 at the last visit, the difference was not statistically significant. Intraocular manifestations observed during the study period included ocular hypertension (14.3%), anterior uveitis (100.0%), retinal hemorrhage (71.4%), vitreous opacity (100.0%), retinal exudative vasculitis (85.7%), optic nerve atrophy (85.7%), retinal vascular occlusion (85.7%), choroidal atrophy (85.7%), macular edema (100.0%), subretinal fluid in the macula (71.4%), and retinal detachment (85.7%). Treatment modalities included oral and intravitreal antivirals (85.7%), antiplatelet medications (85.7%), steroid eye drops (85.7%), subcapsular (57.1%) and vitreous (42.9%) steroid injections, oral steroids (71.4%), and surgical intervention (85.7%). Vitrectomy led to retinal recovery in all five eyes that underwent the procedure. Conclusions The visual prognosis of patients with ARN is poor, particularly in those with preexisting visual impairment. Early detection coupled with antiviral therapy and prompt surgical intervention have been identified as potential factors that influence visual outcomes. Given the severity of ARN, collecting data from multiple centers could aid in devising future diagnostic and therapeutic strategies.

Long-term Efficacy of Oral Valganciclovir in Presumed Cytomegalovirus Unilateral Hypertensive Anterior Uveitis

PURPOSE

To describe long-term efficacy and safety of oral valganciclovir in the treatment of presumed cytomegalovirus (CMV) unilateral hypertensive anterior uveitis.

METHODS

Retrospective review of 40 patients (40 eyes).

RESULTS

All patients presented with high intraocular pressure (mean 39.35 ± 7.58 mmHg), associated with signs of mild anterior uveitis. Oral valganciclovir resulted in control of the intraocular pressures and inflammation in 35 eyes. At the dose of ≥450 mg twice daily, no relapses were documented. The follow-up period ranged from 12 to 108 months (24.45 ± 14.56). At the final follow-up, the intraocular pressure was reduced to 14.92 ± 2.43 mmHg (<0.001). Drug-related complications in the form of leukopenia and azoospermia were reported in one patient.

CONCLUSIONS

Oral valganciclovir effectively and safely controls intraocular pressure and inflammation in presumed CMV anterior uveitis. A long-term treatment course seems necessary.

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.

OUTCOMES OF INFECTIOUS PANUVEITIS ASSOCIATED WITH SIMULTANEOUS MULTI-POSITIVE OCULAR FLUID POLYMERASE CHAIN REACTION

PURPOSE

To evaluate features of infectious panuveitis associated with multiple pathogens detected by ocular fluid sampling.

METHODS

Single-center, retrospective, consecutive case series of patients with aqueous/vitreous polymerase chain reaction testing with >1 positive result in a single sample from 2001 to 2021.

RESULTS

Of 1,588 polymerase chain reaction samples, 28 (1.76%) were positive for two pathogens. Most common pathogens were cytomegalovirus (n = 16, 57.1%) and Epstein-Barr virus (n = 13, 46.4%), followed by varicella zoster virus (n = 8, 28.6%), Toxoplasma gondii (n = 6, 21.4%), herpes simplex virus 2 (n = 6, 21.4%), herpes simplex virus 1 (n = 6, 21.4%), and Toxocara (n = 1, 3.6%). Mean initial and final visual acuity (logarithm of the minimum angle of resolution) were 1.3 ± 0.9 (Snellen ∼20/400) and 1.3 ± 1.1 (Snellen ∼20/400), respectively. Cytomegalovirus-positive eyes (n = 16, 61.5%) had a mean final visual acuity of 0.94 ± 1.1 (Snellen ∼20/175), whereas cytomegalovirus-negative eyes (n = 10, 38%) had a final visual acuity of 1.82 ± 1.0 (Snellen ∼20/1,320) ( P < 0.05). Main clinical features included intraocular inflammation (100%), retinal whitening (84.6%), immunosuppression (65.4%), retinal hemorrhage (38.5%), and retinal detachment (34.6%).

CONCLUSION

Cytomegalovirus or Epstein-Barr virus were common unique pathogens identified in multi-PCR-positive samples. Most patients with co-infection were immunosuppressed with a high rate of retinal detachment and poor final visual acuity. Cytomegalovirus-positive eyes had better visual outcomes compared with cytomegalovirus-negative eyes.

The Role of Corticosteroids and Immunomodulatory Therapy in the Management of Infectious Uveitis

PURPOSE

The index review aims to provide an update on the role of corticosteroids and steroid-sparing immunomodulatory therapy (IMT) in managing patients with infectious uveitis.

METHOD

Narrative literature review.

RESULTS

Corticosteroids and immunomodulatory therapy (IMT) focus on the host defense system instead of the pathogen, adjusting exaggerated inflammatory reactions to reduce potential harm to ocular tissues. Systemic or local corticosteroids are primarily selected as adjunctive medication for infectious uveitis. Concomitant corticosteroids have also been used in cases of paradoxical worsening in ocular tuberculosis and immune recovery uveitis in cytomegalovirus (CMV) retinitis. While there is no well-established evidence to support the use of IMT in infectious uveitis, it is occasionally used in clinical settings to treat persistent inflammation following resolution of infection such as cases of ocular tuberculosis and ocular syphilis where an insufficient response is observed with corticosteroids.

CONCLUSION

There is no consensus on the position of immunomodulatory therapy in the management of infectious uveitis with different etiologies. The index review provides an overview of available adjunctive corticosteroids and IMT options to assist clinicians in managing such disease entities more efficiently.

The Infectious Uveitis Treatment Algorithm Network (TITAN) Report 2-global current practice patterns for the management of Cytomegalovirus anterior uveitis

AIMS

To present current practice patterns in the diagnosis and management of Cytomegalovirus anterior uveitis (CMV AU) by uveitis experts worldwide.

METHODS

A two-round modified Delphi survey with masking of the study team was performed. Based on experience and expertise, 100 international uveitis specialists from 21 countries were invited to participate in the survey. Variation in the diagnostic approaches and preferred management of CMV AU was captured using an online survey platform.

RESULTS

Seventy-five experts completed both surveys. Fifty-five of the 75 experts (73.3%) would always perform diagnostic aqueous tap in suspected CMV AU cases. Consensus was achieved for starting topical antiviral treatment (85% of experts). About half of the experts (48%) would only commence systemic antiviral treatment for severe, prolonged, or atypical presentation. The preferred specific route was ganciclovir gel 0.15% for topical treatment (selected by 70% of experts) and oral valganciclovir for systemic treatment (78% of experts). The majority of experts (77%) would commence treatment with topical corticosteroid four times daily for one to two weeks along with antiviral coverage, with subsequent adjustment depending on the clinical response. Prednisolone acetate 1% was the drug of choice (opted by 70% of experts). Long-term maintenance treatment (up to 12 months) can be considered for chronic course of inflammation (88% of experts) and those with at least 2 episodes of CMV AU within a year (75-88% of experts).

CONCLUSIONS

Preferred management practices for CMV AU vary widely. Further research is necessary to refine diagnosis and management and provide higher-level evidence.

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.

First-line management of necrotizing herpetic retinitis by prioritizing the investigation of immune status and prognostic factors for poor visual outcomes

PURPOSE

To review management, treatment, and outcomes of patients with necrotizing herpetic retinitis (NHR) to propose an algorithm for first-line management of NHR.

METHODS

Retrospective evaluation of a series of patients with NHR at our tertiary center between 2012 and 2021 using demographic, clinical, ophthalmologic, virological, therapeutic, and prognostic characteristics was performed. Patients were classified by NHR type: acute retinal necrosis (ARN), progressive outer retinal necrosis (PORN), cytomegalovirus (CMV) retinitis.

RESULTS

Forty-one patients with NHR were included: 59% with ARN, 7% with PORN, and 34% with CMV retinitis. All patients with CMV retinitis and PORN were immunocompromised versus 21% of patients with ARN. CMV infection was found in 14 (34%) patients, varicella zoster virus infection in 14 (34%) patients, herpes simplex virus type 2 infection in 8 (20%) and type 1 infection in 5 (12%) patients. Intravenous antiviral therapy was received by 98% of patients and intravitreal antiviral injections by 90% of patients. The overall complication rate during follow-up was 83% of eyes. Most frequent complications were retinal detachment (33% eyes) and retinal break (29% eyes). Prognostic factors for poor visual outcomes were pre-existing monocular vision loss in contralateral eye among 17% of patients, bilateral NHR in 17% of patients, posterior pole involvement in 46% of eyes, and involvement > 2 retinal quadrants in 46% of eyes.

CONCLUSIONS

The visual prognosis of patients with NHR remains poor. Prompt investigation of immune status and presence of factors justifying intravitreal antiviral injections must be prioritized to initiate and adapt management while awaiting causative virus confirmation.

Systematic review of clinical practice guidelines for uveitis

To facilitate the integration of eye care into universal health coverage, the WHO is developing a Package of Eye Care Interventions (PECI). Development of the PECI involves the identification of evidence-based interventions from relevant clinical practice guidelines (CPGs) for uveitis.

A systematic review of CPGs published on uveitis between 2010 and March 2020 was conducted. CPGs passing title and abstract and full-text screening were evaluated using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool and data on recommended interventions extracted using a standard data extraction sheet.

Of 56 CPGs identified as potentially relevant from the systematic literature search, 3 CPGs underwent data extraction following the screening stages and appraisal with the AGREE II tool. These CPGs covered screening for, monitoring and treating juvenile idiopathic arthritis (JIA)-associated uveitis, the use of adalimumab and dexamethasone in treating non-infectious uveitis, and a top-level summary of assessment, differential diagnosis and referral recommendations for uveitis, aimed at primary care practitioners. Many of the recommendations were based on expert opinion, though some incorporated clinical study and randomised controlled trial data.

There is currently sparse coverage of the spectrum of disease caused by uveitis within CPGs. This may partially be due to the large number of conditions with diverse causes and clinical presentations covered by the umbrella term uveitis, which makes numerous sets of guidelines necessary. The limited pool of CPGs to select from has implications for clinicians seeking guidance on clinical care strategies for uveitis.

Innate immunity dysregulation in aging eye and therapeutic interventions

The prevalence of eye diseases increases considerably with age, resulting in significant vision impairment. Although the pathobiology of age-related eye diseases has been studied extensively, the contribution of immune-related changes due to aging remains elusive. In the eye, tissue-resident cells and infiltrating immune cells regulate innate responses during injury or infection. But due to aging, these cells lose their protective functions and acquire pathological phenotypes. Thus, dysregulated ocular innate immunity in the elderly increases the susceptibility and severity of eye diseases. Herein, we emphasize the impact of aging on the ocular innate immune system in the pathogenesis of infectious and non-infectious eye diseases. We discuss the role of age-related alterations in cellular metabolism, epigenetics, and cellular senescence as mechanisms underlying altered innate immune functions. Finally, we describe approaches to restore protective innate immune functions in the aging eye. Overall, the review summarizes our current understanding of innate immune functions in eye diseases and their dysregulation during aging.

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.

The impact of aqueous humor polymerase chain reaction and serological test results for establishing infectious uveitis diagnosis: An Indonesian experience

Objective

To assess the clinical value of aqueous humor real-time polymerase chain reaction (RT-PCR) and serological antibody tests among uveitis patients in Indonesian cohort.

Methods

In this prospective cohort study, single-plex RT-PCR analysis of aqueous samples from 86 new uveitis patients was performed to detect Mycobacterium tuberculosis, Toxoplasmosis gondii, cytomegalovirus, herpes simplex virus, varicella-zoster virus, Epstein-Barr virus, and rubella virus. Specific serological antibodies for suspected pathogens were also obtained. Comparison of PCR and serological antibodies with the initial and final diagnosis were presented.

Results

The diagnostic positivity of aqueous RT-PCR in our cohort was 20% (17/86). The rate of infection as final etiological classification was higher after RT-PCR was performed (45 patients, 52%) compared to initial diagnosis based on clinical presentation alone (38 patients, 44%). In particular, the RT-PCR positivity among patients with infection as the final etiological classification was 33.33% (15/45). A significant difference in the IgG but not IgM toxoplasma value among those with ocular toxoplasmosis as the final diagnosis compared to the other etiologies were observed (3953 (IQR 2707–19562) IU/mL vs 428 (IQR 82–1807) IU/mL; p < 0.0001).

Conclusion

RT-PCR analysis of aqueous fluid from uveitis patients helped confirm a third of infectious uveitis cases in Indonesia. In ocular toxoplasmosis, high IgG but not IgM antibody value might help differentiate those with other etiology.

Systemic prime exacerbates the ocular immune response to heat-killed Mycobacterium tuberculosis

Post-infectious uveitis describes the condition of chronic immune mediated ocular inflammation associated with pathogens such as Mycobacterium tuberculosis (Mtb). Mtb associated post-infectious uveitis can be modeled in mice by intravitreal injection of heat-killed Mtb (HKMtb). To better understand how prior systemic exposure to the pathogen alters the local immune response to Mtb, we used flow cytometry and multiplex ELISAs to compare ocular responses to intravitreal HKMtb in the presence or absence of a systemic "prime" of HKMtb. Priming resulted in exacerbation of local inflammation with significantly increased clinical and histologic inflammation scores and increased vitreous cytokines concentrations one day after intravitreal injection of HKMtb. Seven days after injection, uveitis in unprimed animals had largely resolved. In contrast in primed animals, clinical signs of chronic inflammation were associated with a significant increase in the number of ocular T cells, NK cells, and Ly6Chi macrophages and increasing vitreous concentrations of IL-17, VEGF, MIG(CXCL9), IP-10(CXCL10), IL-12p40 and MIP-1α(CCL3). In mice lacking mature T and B cells (RAG2 deficient), the impact of priming on the ocular immune response was ameliorated with significantly lower vitreous cytokine concentrations and spontaneous resolution of uveitis. Altogether these results suggest that the ocular response to Mtb is exacerbated by prior systemic Mtb infection and chronic post-infectious uveitis is mediated by local production of cytokines and chemokines that amplify Th17 and Th1 responses. This mouse model of chronic Mtb associated uveitis will help elucidate mechanisms of disease in patients with post-infectious uveitis.

Identification of uveitis-associated functions based on the feature selection analysis of gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment scores

Uveitis is a typical type of eye inflammation affecting the middle layer of eye (i.e., uvea layer) and can lead to blindness in middle-aged and young people. Therefore, a comprehensive study determining the disease susceptibility and the underlying mechanisms for uveitis initiation and progression is urgently needed for the development of effective treatments. In the present study, 108 uveitis-related genes are collected on the basis of literature mining, and 17,560 other human genes are collected from the Ensembl database, which are treated as non-uveitis genes. Uveitis- and non-uveitis-related genes are then encoded by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment scores based on the genes and their neighbors in STRING, resulting in 20,681 GO term features and 297 KEGG pathway features. Subsequently, we identify functions and biological processes that can distinguish uveitis-related genes from other human genes by using an integrated feature selection method, which incorporate feature filtering method (Boruta) and four feature importance assessment methods (i.e., LASSO, LightGBM, MCFS, and mRMR). Some essential GO terms and KEGG pathways related to uveitis, such as GO:0001841 (neural tube formation), has04612 (antigen processing and presentation in human beings), and GO:0043379 (memory T cell differentiation), are identified. The plausibility of the association of mined functional features with uveitis is verified on the basis of the literature. Overall, several advanced machine learning methods are used in the current study to uncover specific functions of uveitis and provide a theoretical foundation for the clinical treatment of uveitis.

Acute syphilitic posterior placoid chorioretinitis as the presenting symptom of syphilis in an immunocompetent patient

Purpose

Observations

Conclusions and Importance

Risk of anxiety and depression in patients with uveitis: a Meta-analysis

AIM

To quantitatively evaluate the risk of anxiety and depression in patients with uveitis via performing a Meta-analysis.

METHODS

Three electronic database (PubMed, Embase, and Cochrane Library databases) were searched for studies recording data about uveitis and anxiety as well as depression simultaneously up to January 2021. The incidence rate and standard mean difference (SMD) with a 95% confidence interval (95%CI) were calculated to analyse the association using random-effects models based on heterogeneity tests.

RESULTS

In total, 12 observational studies containing 874 patients with uveitis were included. The results showed that there was a significant association between uveitis and anxiety (SMD=0.97, 95%CI: 0.39 to 1.54, P=0.0009) and depression (SMD=0.79, 95%CI: 0.51 to 1.07, P<0.00001). The overall morbidities of anxiety and depression in patients with uveitis were 39% and 17%, respectively. With subgroup analysis, the heterogeneity actually came from different kinds of uveitis. Specifically, the incidence rates of both anxiety and depression were relatively low in patients with anterior uveitis (33% and 15%), moderate in patients with infectious uveitis (46% and 22%), and high in patients with unspecified uveitis (59% and 35%).

CONCLUSION

It is preliminarily indicated that patients with uveitis may have a high risk of anxiety and depression. Ophthalmologists and psychologists should pay more attention to the psychological state when dealing with patients with uveitis. Further high-quality studies with detailed direct data are needed to draw more precise conclusions.

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.

Fungi of the human eye: Culture to mycobiome

The focus of the current review is multi-fold and compares the diversity and abundance of fungi on the ocular surface by the conventional culture-based method with the more sensitive, high throughput, culture-independent NGS method. The aim is to highlight the existence of a core ocular mycobiome and explore the transition of the ocular fungal microbiota from the normal eye to the diseased eye. PubMed, Google Scholar and Medline were used to search for publications and reviews related to cultivable fungi and the mycobiome of the normal and diseased eye. The conventional cultivable approach and the NGS approach confirm that the eye has its own mycobiome and several confounding factors (age, gender, ethnicity etc.) influence the mycobiome. Further, dysbiosis in the mycobiome appears to be associated with ocular diseases and thus impacts the health of the human eye. Considering that the mycobiome of the eye is influenced by several confounding factors and also varies with respect to the disease status of the eye there is a need to extensively explore the mycobiome under different physiological conditions, different ethnicities, geographical regions etc. Such studies would unravel the diversity and abundance of the mycobiomes and contribute to our understanding of ocular health. Research focused on ocular mycobiomes may eventually help to build a targeted and individualized treatment.

Spirochetal uveitis: Spectrum of clinical manifestations, diagnostic and therapeutic approach, final outcome and epidemiological data

PURPOSE

Analysis of cases with spirochetal uveitis related to spirochetes in a tertiary referral academic center.

METHODS

Retrospective study of patients diagnosed with uveitis attributed to Treponema pallidum, Leptospira spp. and Borrelia burgdorferi from June 1991 until December 2019.

RESULTS

A total of 57 cases of spirochetal uveitis (22 patients with T. pallidum, 26 with Leptospira spp., and 9 with B. burgdorferi) that consisted 1% of the overall number of uveitics were recorded. All these cases presented with a wide spectrum of clinical presentations (anterior uveitis, posterior uveitis, panuveitis, vasculitis, papillitis, and in some rare cases concomitant posterior scleritis). The treatment included mainly penicillin or doxycycline, while corticosteroids were administered systematically in some cases with Borrelia or Leptospira infection. The final visual outcome was favorable (> 6/10 in Snellen visual acuity) in approximately 76% of our patients.

CONCLUSION

Despite being rare, spirochetal uveitis can be detrimental for the vision and must always be included in the differential diagnosis.

Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Ocular Infections

The variety and complexity of ocular infections have increased significantly in the last decade since the publication of Cumitech 13B, Laboratory Diagnosis of Ocular Infections (L. D. Gray, P. H. Gilligan, and W. C. Fowler, Cumitech 13B, Laboratory Diagnosis of Ocular Infections, 2010). The purpose of this practical guidance document is to review, for individuals working in clinical microbiology laboratories, current tools used in the laboratory diagnosis of ocular infections. This document begins by describing the complex, delicate anatomy of the eye, which often leads to limitations in specimen quantity, requiring a close working bond between laboratorians and ophthalmologists to ensure high-quality diagnostic care. Descriptions are provided of common ocular infections in developed nations and neglected ocular infections seen in developing nations. Subsequently, preanalytic, analytic, and postanalytic aspects of laboratory diagnosis and antimicrobial susceptibility testing are explored in depth.

Keys to Unlock the Enigma of Ocular Toxocariasis: A Systematic Review and Meta-analysis

Purpose: Ocular toxocariasis (OT) is a zoonotic infection caused by larval stages of Toxocara canis and T. cati. The current review and meta-analysis aimed to evaluate the global prevalence of OT.Methods: Five English (PubMed, Scopus, Science Direct, Web of Science, and Google Scholar) databases were explored and 101 articles met the inclusion criteria.Results: The pooled prevalence (95% confidence interval) of OT was higher in immunological studies (9%. 6-12%) than in studies that applied ophthalmic examination (1%. 1-2%). The lower middle-income level countries had the highest prevalence (6%. 2-12%) as well as the African region (10%. 7-13%). The highest infection rate (4%. 2-7%) was detected in the 1-25 mean age group.Conclusion: Regular anthelminthic treatment of cats and dogs, and removal of animal feces from public places must be considered.

Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides

Isolation of antimicrobial-resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic-resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic-resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first-line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin-resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad-spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.

Microbes of the human eye: Microbiome, antimicrobial resistance and biofilm formation

BACKGROUND

The review focuses on the bacteria associated with the human eye using the dual approach of detecting cultivable bacteria and the total microbiome using next generation sequencing. The purpose of this review was to highlight the connection between antimicrobial resistance and biofilm formation in ocular bacteria.

METHODS

Pubmed was used as the source to catalogue culturable bacteria and ocular microbiomes associated with the normal eyes and those with ocular diseases, to ascertain the emergence of anti-microbial resistance with special reference to biofilm formation.

RESULTS

This review highlights the genetic strategies used by microorganisms to evade the lethal effects of anti-microbial agents by tracing the connections between candidate genes and biofilm formation.

CONCLUSION

The eye has its own microbiome which needs to be extensively studied under different physiological conditions; data on eye microbiomes of people from different ethnicities, geographical regions etc. are also needed to understand how these microbiomes affect ocular health.

Clinical utility of aqueous humor polymerase chain reaction and serologic testing for suspected infectious uveitis: a single-center retrospective study in South Korea

Background

This study aimed to assess and compare the clinical value of aqueous humor polymerase chain reaction (PCR) and serologic tests in patients diagnosed with suspected infectious uveitis.

Methods

In this retrospective observational study, data of 358 patients who were diagnosed with suspected infectious uveitis and who underwent aqueous humor PCR testing were analyzed. PCR and serologic test results were compared with the clinical features.

Results

The rates of initial diagnoses for infectious uveitis were higher with PCR (99 patients, 28%) compared to those with serologic tests (38 pateints, 11%). The diagnostic positivity of PCR was 29% for anterior uveitis, 0% for intermediate uveitis, 5% for posterior uveitis, and 30% for panuveitis. In particular, PCR was useful in confirming the diagnosis of cytomegalovirus and varicella-zoster virus infections and Toxoplasma gondii-associated uveitis. For PCR test, the sensitivity was 0.431, specificity was 0.985, and the negative and positive predictive values were 0.506 and 0.980, respectively. For IgM test, the sensitivity was 0.151, specificity was 0.970, and the negative and positive predictive values were 0.403 and 0.895, respectively.

Conclusion

Aqueous humor PCR can be a valuable diagnostic tool for confirming the infectious etiology in patients clinically diagnosed with uveitis. PCR had good predictive and diagnostic value for anterior uveitis and panuveitis compared with that for intermediate and posterior uveitis.

Attenuation of experimental autoimmune uveoretinitis in mice by IKKβ inhibitor IMD-0354

Uveitis is a sight-threatening intraocular inflammatory disease that accounts for almost 10% of blindness worldwide. NF-κB signaling plays pivotal roles in inflammatory diseases. We have reported that IMD-0354, which inhibits NF-κB signaling via selective blockade of IKK-β, suppresses inflammation in several ocular disease models. Here, we examined the therapeutic effect of IMD-0354 in an experimental autoimmune uveoretinitis (EAU) model, a well-established animal model for endogenous uveitis in humans. Systemic administration of IMD-0354 significantly suppressed the clinical and histological severity, inflammatory edema, and the translocation of NF-κB p65 into the nucleus of retinas in EAU mice. Furthermore, IMD-0354 treatment significantly inhibited the levels of several Th1/Th17-mediated pro-inflammatory cytokines in vitro. Our current data demonstrate that inhibition of IKKβ with IMD-0354 ameliorates inflammatory responses in the mouse EAU model, suggesting that IMD-0354 may be a promising therapeutic agent for human endogenous uveitis.

A Pyrrhic Victory: The PMN Response to Ocular Bacterial Infections

Some tissues of the eye are susceptible to damage due to their exposure to the outside environment and inability to regenerate. Immune privilege, although beneficial to the eye in terms of homeostasis and protection, can be harmful when breached or when an aberrant response occurs in the face of challenge. In this review, we highlight the role of the PMN (polymorphonuclear leukocyte) in different bacterial ocular infections that invade the immune privileged eye at the anterior and posterior segments: keratitis, conjunctivitis, uveitis, and endophthalmitis. Interestingly, the PMN response from the host seems to be necessary for pathogen clearance in ocular disease, but the inflammatory response can also be detrimental to vision retention. This "Pyrrhic Victory" scenario is explored in each type of ocular infection, with details on PMN recruitment and response at the site of ocular infection. In addition, we emphasize the differences in PMN responses between each ocular disease and its most common corresponding bacterial pathogen. The in vitro and animal models used to identify PMN responses, such as recruitment, phagocytosis, degranulation, and NETosis, are also outlined in each ocular infection. This detailed study of the ocular acute immune response to infection could provide novel therapeutic strategies for blinding diseases, provide more general information on ocular PMN responses, and reveal areas of bacterial ocular infection research that lack PMN response studies.

Role of Herpes Simplex Envelope Glycoprotein B and Toll-Like Receptor 2 in Ocular Inflammation: An ex vivo Organotypic Rabbit Corneal Model

It has been recently reported, using in vitro studies, that the herpes simplex virus 1 (HSV-1) encoded envelope glycoprotein B (gB1) interacts with cell surface toll-like receptor 2 (TLR2) and induces the secretion of interleukin-8 (IL8), a representative marker of inflammatory cytokine activation. The purpose of this study is to investigate the role of gB1 in activating host inflammatory responses by using a secreted form of gB1 (gB1s) and an ex vivo organotypic rabbit corneal model. Abraded corneas exposed to gB1s alone or to the recombinant protein mixed with anti gB polyclonal antibody were cultured in an air-liquid interface. The corneas exposed to gB1s show the appearance of mydriasis and high levels of TLR2 and IL-8 mRNAs transcripts were detected in the superficial layer of corneal epithelial cells. Histological stain and immunohistochemical analyses revealed morphological changes in the epithelium of the treated corneas and variations in expression and localization of TLR2. Collectively these findings provide new insight into the pathogenesis of HSV-1 ocular infection by demonstrating the leading role of gB in activating an inflammatory response and in the appearance of mydriasis, a sign of HSV-1 anterior uveitis.

Varicella-zoster virus as a causative agent of acute retinal necrosis in younger patients

Background:

Herpes virus is considered to be the pathogen of acute retinal necrosis (ARN) infection. Previous studies have found that patients with ARN caused by the varicella-zoster virus (VZV) are often older, and patients with herpes simplex virus (HSV) induced ARN are considerably younger. However, in our clinical work, we find that VZV is also a pathogen in younger ARN patients. We, therefore, aimed to analyze the common etiology of younger ARN patients.

Methods:

A retrospective analysis was made of 20 eyes (18 patients) diagnosed as having ARN in the Department of Ophthalmology of Peking Union Medical College Hospital from 2014 to 2016. All patients were reviewed for demographic data, clinical course, clinical manifestations, time from onset to initial physician visit, duration of follow-up, visual acuity at both presentation and final visit, and treatment strategies. A paired t test was used to compare visual acuity between the presenting vision and those of final follow-up. Vitreous or aqueous specimens from 18 eyes of 18 patients were analyzed with multiplex polymerase chain reaction (mPCR)/quantitative PCR (qPCR) and xTAG-liquid chip technology (xTAG-LCT) to determine the causative virus of ARN.

Results:

Final best visual acuity (BCVA) improved significantly from 1.36 ± 0.95 (median 20/400) to 0.95 ± 0.82 (median 20/100) (t = 2.714, P = 0.015) after systemic and intravitreal antiviral treatment combined with or without pars plana vitrectomy. PCR and xTAG-LCT results showed four of the five samples in the younger group (32.2 ± 5.2 years) and 12 of the 13 samples in the senior group (53.6 ± 4.9 years) were positive for VZV, and two of the five samples in the younger group were positive for HSV-1.

Conclusions:

This study demonstrates that VZV is also a common causative virus for ARN in younger patients. Considering this finding, a systemic antiviral treatment protocol should be immediately changed to intravenous ganciclovir when the patient does not respond to acyclovir before determining the causative virus, especially in younger patients.

Modern Therapeutic Approaches for Noninfectious Ocular Diseases Involving Inflammation

Dry eye disease, age-related macular degeneration, and uveitis are ocular diseases that significantly affect the quality of life of millions of people each year. In these diseases, the action of chemokines, proinflammatory cytokines, and immune cells drives a local inflammatory response that results in ocular tissue damage. Multiple therapeutic strategies are developed to either address the symptoms or abate the underlying cause of these diseases. Herein, the challenges to deliver drugs to the relevant location in the eye for each of these diseases are reviewed along with current and innovative therapeutic approaches that attempt to restore homeostasis within the ocular microenvironment.

Combined Intravitreal and Systemic Antibiotic Therapy in a Patient with Syphilitic Uveitis

PURPOSE

To report the novel use of combined intravitreal and systemic antibiotic therapy in a patient with syphilitic panuveitis and discuss the management of ocular syphilis.

METHODS

Case report Results: A 45-year old heterosexual male with human immunodeficiency virus (HIV) presented with 1 month of blurry vision in both eyes. Clinical examination revealed a bilateral panuveitis. The patient denied history of genital lesions or rash, but did complain of difficulty hearing bilaterally. Treponemal EIA was positive, the RPR titer greater than 1:512 dilution, and CSF VDRL 1:4. A diagnosis of neurosyphilis and ocular syphilis was made based on the clinical and laboratory findings. The patient was admitted for systemic intravenous antibiotic therapy, but was noted to have a penicillin allergy. Intravitreal ceftazidime was promptly administered bilaterally to achieve treponemacidal levels of antibiotic therapy. After penicillin desensitization protocol, the patient received 14 days of intravenous penicillin with clinical resolution.

CONCLUSIONS

There are increasing reports of ocular syphilis in the United States and delay in diagnosis and management can lead to severe visual impairment and blindness. We report the first case of adjunct intravitreal antibiotic therapy in a penicillin allergic patient. As ocular syphilis is a form of bacterial endophthalmitis, combination intravitreal and systemic antibiotics may be considered.