Vaccines and the Eye: Current Understanding of the Molecular and Immunological Effects of Vaccination on the Eye.

Vaccination is a public health cornerstone that protects against numerous infectious diseases. Despite its benefits, immunization implications on ocular health warrant thorough investigation, particularly in the context of vaccine-induced ocular inflammation. This review aimed to elucidate the complex interplay between vaccination and the eye, focusing on the molecular and immunological pathways implicated in vaccine-associated ocular adverse effects. Through an in-depth analysis of recent advancements and the existing literature, we explored various mechanisms of vaccine-induced ocular inflammation, such as direct infection by live attenuated vaccines, immune complex formation, adjuvant-induced autoimmunity, molecular mimicry, hypersensitivity reactions, PEG-induced allergic reactions, Type 1 IFN activation, free extracellular RNA, and specific components. We further examined the specific ocular conditions associated with vaccination, such as uveitis, optic neuritis, and retinitis, and discussed the potential impact of novel vaccines, including those against SARS-CoV-2. This review sheds light on the intricate relationships between vaccination, the immune system, and ocular tissues, offering insights into informed discussions and future research directions aimed at optimizing vaccine safety and ophthalmological care. Our analysis underscores the importance of vigilance and further research to understand and mitigate the ocular side effects of vaccines, thereby ensuring the continued success of vaccination programs, while preserving ocular health.

Profiles, Distribution, and Functions of Gamma Delta T Cells in Ocular Surface Homeostasis and Diseases.

The ocular surface microenvironment, containing the cornea, conjunctiva, and lacrimal gland, constitutes the mucosal frontline of the eye and houses a myriad of immune cells. As a part of unconventional T cells, gamma delta (γδ) T cells differ in the development and functions from canonical alpha beta (αß) T cells. They are predominantly situated in mucosal sites throughout the body, including ocular surface tissues. Recent research has elucidated that γδ T cells serve as the primary interleukin-17A (IL-17A) source in the conjunctiva. They play a pivotal role in preserving ocular surface homeostasis and exhibit both protective and pathogenic roles in ocular surface diseases. This review delves into the general profiles of γδ T cells, their distribution in ocular surface tissues, and consolidates current insights into their functions in different conditions including dry eye disease, infectious keratitis, corneal wound healing, anterior chamber-associated immune deviation, allergic conjunctival disease, and diabetic ocular surface disease. The aim is to provide a systemic perspective on γδ T cells in the ocular surface microenvironment and outline potential directions for future studies.

The Role of Symptom Duration and Serologic Factors in the Relapse of IgG4-Related Ophthalmic Disease following Surgery: A Retrospective Cohort Study.

IgG4-related disease (IgG4-RD) affects multiple organs and is characterized by immune-mediated inflammation and fibrosis; IgG-RD affecting orbital tissue is known as IgG4-related ophthalmic disease (IgG4-ROD). This research is aimed at exploring whether symptom duration and common serologic factors, such as IgG, IgE, and eosinophils, are potential risk factors for IgG4-ROD patient relapse after surgery and identifying possible causes of the positive correlation between symptom duration and relapse. This retrospective cohort study included 40 IgG4-ROD patients after surgery. Auxiliary inspection results were obtained before surgery and during follow-up, and relapse risk factors were identified based on previous studies. We used the Spearman rank correlation test to reveal the relationship between symptom duration and relapse time and identified the optimal cutoff value for symptom duration by X-tile. Then, we divided the patients into the long-duration and short-duration groups. Kaplan-Meier survival analyses and log-rank tests were performed to identify the relationship between symptom duration and relapse using X-tile software. Finally, we studied the relationship between previously studied relapse risk factors and symptom duration. The survival curves of the long-duration and short-duration groups were obviously different, and the baseline serum IgG, IgE, and eosinophil levels and asthma concomitant rate were significantly different between the long-duration and short-duration groups. Furthermore, the baseline serum IgG (r = 0.485, P = 0.002), IgE (r = 0.350, P = 0.037), and eosinophil (r = 0.6535, P < 0.0001) levels were positively correlated with symptom duration. Our study shows that IgG4-ROD symptom duration is significantly positively correlated with relapse rate and negatively correlated with relapse time. Symptom duration was positively correlated with serum baseline IgG4, IgE, and eosinophil levels and asthma history, which were potential risk factors for disease relapse. We recommended that IgG4-ROD patients with symptom durations greater than 96 months continue to receive maintenance steroid therapy longer than 1 year postsurgery to reduce the relapse rate.

Ophthalmologic manifestations in patients with antiphospholipid antibodies: Beware of iatrogenic complications.

BACKGROUND: Antiphospholipid syndrome (APS) is characterized by several clinical manifestations such as venous and arterial thrombosis associated with persistent antiphospholipid antibodies (aPL). Several studies confirmed that retinal vein occlusion was the most common APS ocular manifestation. The purpose of this study was to identify ophthalmologic manifestations in a homogeneous cohort of well-defined persistently aPL-positive patients and to determine variables associated with these manifestations. METHODS: APL-positive patients were selected from two research programs. All ophthalmologic manifestations including those related to APS were recorded. RESULTS: A total of 117 patients were included and 10 of them had APS-related ophthalmologic manifestations (glaucoma, hydroxychloroquine-related maculopathy, anterior acute uveitis, anterior ischemic optic neuropathy). Systemic Lupus Erythematosus (SLE) (OR = 3.4[95%CI; 0.9-12.7), corticosteroids (OR = 9.0 [95%CI; 2.2-37.7]) and aPL-related nephropathy (OR = 7.1 [95%CI; 1.7-30.0]) were significatively associated with the risk of APS-related ophthalmologic manifestations. CONCLUSION: Most of ocular manifestations in this study were iatrogenic related to corticosteroids or hydroxychloroquine. Patients with SLE, small vessel thrombosis in general, or with aPL-related nephropathy in particular, seemed at higher risk to develop APS-related ophthalmologic manifestations thus deserving adequate monitoring.

Cutaneous and ocular rosacea: Common and specific physiopathogenic mechanisms and study models.

Rosacea is a chronic inflammatory disease that affects the face skin. It is clinically classified into the following four subgroups depending on its location and severity: erythematotelangiectatic, papulopustular, phymatous, and ocular. Rosacea is a multifactorial disease triggered by favoring factors, the pathogenesis of which remains imperfectly understood. Recognized mechanisms include the innate immune system, with the implication of Toll-like receptors (TLRs) and cathelicidins; neurovascular deregulation involving vascular endothelial growth factor (VEGF), transient receptor potential (TRP) ion channels, and neuropeptides; and dysfunction of skin sebaceous glands and ocular meibomian glands. Microorganisms, genetic predisposition, corticosteroid treatment, and ultraviolet B (UVB) radiation are favoring factors. In this paper, we review the common and specific molecular mechanisms involved in the pathogenesis of cutaneous and ocular rosacea and discuss laboratory and clinical studies, as well as experimental models.

Age-related changes in ocular mucosal tolerance: Lessons learned from gut and respiratory tract immunity.

The ocular surface is the part of the visual system directly exposed to the environment, and it comprises the cornea, the first refractive tissue layer and its surrounding structures. The ocular surface has evolved to keep the cornea smooth and wet, a prerequisite for proper sight, and also protected. To this aim, the ocular surface is a bona fide mucosal niche with an immune system capable of fighting against dangerous pathogens. However, due to the potential harmful effects of uncontrolled inflammation, the ocular surface has several mechanisms to keep the immune response in check. Specifically, the ocular surface is maintained inflammation-free and functional by a particular form of peripheral tolerance known as mucosal tolerance, markedly different from the immune privilege of intraocular structures. Remarkably, conjunctival tolerance is akin to the oral and respiratory tolerance mechanisms found in the gut and airways, respectively. And also similarly, this form of immunoregulation in the eye is affected by ageing just as it is in the digestive and respiratory tracts. With ageing comes an increased prevalence of immune-based ocular surface disorders, which could be related to an age-related impairment of conjunctival tolerance. The purpose of this review was to summarize the present knowledge of ocular mucosal tolerance and how it is affected by the ageing process in the light of the current literature on mucosal immunoregulation of the gut and airways.

Therapy of ocular complications in ANCA+ associated vasculitis.

ANCA+ associated vasculitis (AAV) is a group of rare diseases with potentially vision-threatening complications. Ocular and orbital complications of these diseases are caused by vasculitis of the small vessels of the eye or by granulomatous mass formation. ANCA (anti-neutrophil cytoplasmic antibodies) represent a key component of pathophysiological pathways as well as a diagnostic marker. Various manifestations are reported in literature, scleritis and episcleritis being the most common, followed by pseudotumor orbitae. In vision-threatening orbital or ocular disease, aggressive systemic treatment with a combination of high-dose glucocorticoids and either cyclophosphamide or rituximab is needed. Certain cases require locoregional surgical management to preserve ocular integrity or vision. Ocular involvement of AAV remains a challenge in clinical practice, requiring multi-specialty cooperation in order to ensure the best possible visual outcome. Abbreviations: AAV = ANCA+ associated vasculitis, ANCA = anti-neutrophil cytoplasmic antibodies, GPA = granulomatosis with polyangiitis, EGPA = eosinophilic granulomatosis with polyangiitis, MPA = microscopic polyangiitis.

Drops of Lactiplantibacillus plantarum CRL 759 culture supernatant attenuates eyes inflammation induced by lipopolysaccharide.

Anti-inflammatory effect of soluble secreted compounds of probiotic bacteria was widely demonstrated as therapy for different inflammatory diseases, but was not investigated in inflammatory eye disorders. The aim of this study was to determine whether Lactiplantibacillus plantarum CRL759 cell-free supernatant reduced inflammatory parameters and clinical signs in ocular inflammations. First, we evaluated the effect of L. plantarum CRL759 supernatant in vitro on human retinal cell line, ARPE-19 cells, stimulated with lipopolysaccharide (LPS). Then, we investigated in vivo its capacity to decrease inflammation by local administration on the eyes of mice with endotoxin induced inflammation. In vitro assays demonstrated that L. plantarum CRL759 supernatant reduced the production of interleukin (IL)-6, IL-8, nitric oxide and thiobarbituric acid reactive substances in LPS-stimulated ARPE-19 cells. Our in vivo data proved that L. plantarum supernatant significantly reduced the clinical score of endotoxin treated mice and diminished levels of tumour necrosis factor alpha, interferon gamma and protein concentration in aqueous humour. Histological examination showed reduction of infiltrating inflammatory cells in the posterior segment of the eyes. As far as we know, this is the first report showing that Lactobacillus spp. supernatant administered as drops reduces some parameters of ocular inflammation. This promising strategy is safe and could alleviate symptoms and signs of ocular inflammation in people that are refractories to the conventional therapies.

Toxicity Evaluation of a Novel Rapamycin Liposomal Formulation After Subconjunctival and Intravitreal Injection.

Purpose: Safety and toxicity evaluation of a novel, liposome-encapsulated rapamycin formulation, intended for autoimmune ocular disorders. Methods: The formulation was assessed by micronucleus polychromatic erythrocyte production, irritability by Hen's Egg Test-Chorioallantoic Membrane (HET CAM), sterility, and pyrogenicity testing. Subconjunctival (SCJ) and intravitreal (IVT) administration of the formulation were performed to evaluate subacute and acute toxicity, respectively. Differences between groups in biochemical and hematological parameters were evaluated by analysis of variance and t-tests. Numeric score was assigned to histopathological classification. Electroretinography (ERG) testing was also performed. Data were analyzed by a 1 way no parametric Kruskal-Wallis and the Mann-Whitney tests. Significance was considered when P < 0.05. Results: No significant toxicity directly related to the preparation was detected. Micronucleus count, mucous irritation score, and pyrogenicity results were negative. Pathology demonstrated no damage related to the formulation after SCJ injection. After IVT injection, only lens injury associated with technique was observed. Retinal function was also conserved in ERG. Conclusions: The preparation evaluated offers a good toxicity and safety profile when injected in a SCJ or IVT manner in an animal model. A clinical trial conducted in humans is highly warranted, as it could reveal an alternative immunosuppressive treatment for ophthalmological immune-mediated pathologies.

Human leukocyte antigen B*0702 is protective against ocular Stevens-Johnson syndrome/toxic epidermal necrolysis in the UK population.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis (SJS/TEN) are part of a disease continuum of vesiculobullous mucocutaneous reactions affecting the skin and mucous membranes including the ocular surface. Manifestations of disease range from mild dry eye to progressive conjunctival cicatrisation, limbal epithelial stem cell failure and corneal blindness. In Far Eastern and South East Asian populations where SJS/TEN is prevalent, numerous human leukocyte antigen (HLA) gene variants at the A, B and C loci have been identified as risk factors for developing SJS/TEN with severe ocular complications (SOC). By contrast, the incidence of SJS/TEN with SOC in European countries is relatively low. To date, ocular SJS/TEN risk altering alleles have not been widely investigated in European populations. In this study, we analysed the association of HLA -A, -B and -C alleles with SJS/TEN in 33 patients residing in the UK with age matched controls. The data showed statistically significant novel negative allele association with HLA-B*0702 and a trend with HLA-C*0702 in the patient group, indicating these alleles are protective. Further characterisation of protective and risk alleles in other ethnic groups is required to fully elucidate the putative role of these alleles in the susceptibility of SJS/TEN with or without severe ocular complications in patients in the UK.

Involvement of ocular surface in graft-versus-host disease: An update from immunopathogenesis to treatment.

Graft-versus-host disease is a common complication of hematopoietic stem cell transplantation and the ocular surface is a main target of inflammatory reaction.

Genome-Wide Association Study of Ocular Sarcoidosis Confirms HLA Associations and Implicates Barrier Function and Autoimmunity in African Americans.

Purpose: Identify genes associated with ocular sarcoidosis (OS).Methods: We genotyped 1.1 million genetic variants to identify significant OS associations, defined as those that achieved p < 5 × 10-8 in a genome-wide comparison of OS cases to healthy controls in our European- or African-American cohorts (EA, AA). Potential functional roles of all associated variants were assessed.Results: Eight significant non-HLA variants were found in AA OS cases compared to healthy controls and confirmed as at least suggestive when comparing OS to non-OS cases. Seven of these were within MAGI1 and include transcription factor binding sites and expression quantitative trait loci. Our EA cohort, while showing similar effect sizes at variants within MAGI1, had no significant variants. Association analysis of HLA-DRB1 alleles confirmed association to OS in EA to *04:01.Conclusion: Our results support organ-specific genetic risk in OS in a compelling candidate, MAGI1, known to be associated with barrier function and autoimmunity.

Multidisciplinary management of auto-immune ocular diseases in adult patients by ophthalmologists and rheumatologists.

PURPOSE: Management of chronic vision threatening auto-immune ocular diseases (AIOD, e.g. uveitis, scleritis) can be challenging. Guidelines recommend a multidisciplinary approach (MDA) with ophthalmologists and rheumatologists, to enhance the recognition of systemic diseases and guide the use of immunosuppressives. However, the indications and results of such an approach have not yet been studied. METHODS: A monocentre, retrospective chart review of all patients treated in a MDA between ophthalmologists and rheumatologists, in a Dutch tertiary center. The collaboration was twofold: a combined multidisciplinary team meeting every 2 weeks, and an ophthalmology-dedicated rheumatology outpatient clinic. Primary endpoints of this descriptive study were as follows: indications for MDA, new diagnoses of systemic auto-immune diseases and changes in systemic immunosuppression and prednisone dosages. RESULTS: In total, 157 adults (mean age 46 years, 57% female, median disease duration 19 months) were included, mainly with uveitis (74%) and scleritis (12%). Multidisciplinary approach (MDA)-indications included diagnostic workup (32%), treatment support (44%), diagnostic-and-treatment support (10%) and side effects (8%). A systemic disease was newly diagnosed in eight and already present in 34 patients. At baseline, 54 patients used oral prednisone at >7.5 mg/day. Non-corticoid immunosuppressives, mostly methotrexate, were started in 41% of the patients. During follow-up, systemic prednisone was lowered to ≤7.5 mg/day in 68% of the patients. CONCLUSION: This evaluation of an MDA-programme in the management of AIOD demonstrated its added value. Mainly, it addressed the high demand for support in managing systemic immunosuppression, resulting in significant corticosteroid tapering. In addition, it resulted in the recognition of underlying systemic diseases.

Mouse Models of Sjögren's Syndrome with Ocular Surface Disease.

Sjögren's syndrome (SS) is a systemic rheumatic disease that predominantly affects salivary and lacrimal glands resulting in oral and ocular dryness, respectively, referred to as sicca symptoms. The clinical presentation of ocular dryness includes keratoconjunctivitis sicca (KCS), resulting from the inflammatory damage to the ocular surface tissues of cornea and conjunctiva. The diagnostic evaluation of KCS is a critical component of the classification criteria used by clinicians worldwide to confirm SS diagnosis. Therapeutic management of SS requires both topical and systemic treatments. Several mouse models of SS have contributed to our current understanding of immunopathologic mechanisms underlying the disease. This information also helps develop novel therapeutic interventions. Although these models address glandular aspects of SS pathology, their impact on ocular surface tissues is addressed only in a few models such as thrombospondin (TSP)-1 deficient, C57BL/6.NOD.Aec1Aec2, NOD.H2b, NOD.Aire KO, and IL-2Rα (CD25) KO mice. While corneal and/or conjunctival damage is reported in most of these models, the characteristic SS specific autoantibodies are only reported in the TSP-1 deficient mouse model, which is also validated as a preclinical model. This review summarizes valuable insights provided by investigations on the ocular spectrum of the SS pathology in these models.

Pathophysiology of ocular toxoplasmosis: Facts and open questions.

Infections with the protozoan parasite Toxoplasma gondii are frequent, but one of its main consequences, ocular toxoplasmosis (OT), remains poorly understood. While its clinical description has recently attracted more attention and publications, the underlying pathophysiological mechanisms are only sparsely elucidated, which is partly due to the inherent difficulties to establish relevant animal models. Furthermore, the particularities of the ocular environment explain why the abundant knowledge on systemic toxoplasmosis cannot be just transferred to the ocular situation. However, studies undertaken in mouse models have revealed a central role of interferon gamma (IFNγ) and, more surprisingly, interleukin 17 (IL17), in ocular pathology and parasite control. These studies also show the importance of the genetic background of the infective Toxoplasma strain. Indeed, infections due to exotic strains show a completely different pathophysiology, which translates in a different clinical outcome. These elements should lead to more individualized therapy. Furthermore, the recent advance in understanding the immune response during OT paved the way to new research leads, involving immune pathways poorly studied in this particular setting, such as type I and type III interferons. In any case, deeper knowledge of the mechanisms of this pathology is needed to establish new, more targeted treatment schemes.

COVID-19: the novel coronavirus disease and its manifestations and management in ophthalmology.

Coronavirus disease 2019 (COVID-19), a newly identified acute respiratory disease caused by a strain of novel coronavirus (SARS-CoV-2), has become a worldwide pandemic. From December 2019 to present, millions of cases have been reported, bringing unprecedented pressure on both health and epidemic prevention services in every country. As frontline healthcare workers, ophthalmologists face an increased threat of viral infection, not only because of close contact with patients during examinations or operations, but also due to evidence showing that ocular fluids such as tears or conjunctival secretions may carry the virus. The risk that healthcare workers face is emphasized by the loss of our colleagues who have sacrificed themselves in combating the virus. As a result, it is necessary to have a comprehensive understanding of the threats that we face. In the first part of this review, we start by explaining the structure of SARS-CoV-2 and examining its transmission and means of infection. Next, we summarize the latest scientific advancements of epidemiology, clinical presentations, and current treatments of COVID-19. In the second half of the review, we emphasize the ocular transmission, symptomatic manifestations, and the essential knowledge in an ophthalmology clinic setting. As the pandemic of COVID-19 continues to pose a threat to global health, we hope that this review makes a contribution to combating COVID-19.

Label-free imaging of immune cell dynamics in the living retina using adaptive optics.

Our recent work characterized the movement of single blood cells within the retinal vasculature (Joseph et al. 2019) using adaptive optics ophthalmoscopy. Here, we apply this technique to the context of acute inflammation and discover both infiltrating and tissue-resident immune cells to be visible without any labeling in the living mouse retina using near-infrared light alone. Intravital imaging of immune cells can be negatively impacted by surgical manipulation, exogenous dyes, transgenic manipulation and phototoxicity. These confounds are now overcome, using phase contrast and time-lapse videography to reveal the dynamic behavior of myeloid cells as they interact, extravasate and survey the mouse retina. Cellular motility and differential vascular responses were measured noninvasively and in vivo across hours to months at the same retinal location, from initiation to the resolution of inflammation. As comparable systems are already available for clinical research, this approach could be readily translated to human application.

Clinical management of the most common extra-intestinal manifestations in patients with inflammatory bowel disease focused on the joints, skin and eyes.

Extra-intestinal manifestations (EIMs) of inflammatory bowel disease (IBD) occur frequently and contribute to morbidity and reduced quality of life. The musculoskeletal, ocular and cutaneous organ systems are frequently involved in IBD-related EIMs. By focusing on manifestations involving the joints, skin and eyes, this review will discuss the most common clinically relevant and burdensome EIMs that affect IBD patients, and strives for early recognition, adequate treatment and timely referral. For this purpose, we aimed to create a comprehensive overview on this topic, with the main focus on the treatment of reactive and associated EIMs, including spondyloarthropathies, pyoderma gangrenosum, erythema nodosum, psoriasis and anterior uveitis. The recently developed biologicals enable simultaneous treatment of inflammatory disorders. This review can be used as a helpful guide in daily clinical practice for physicians who are involved in the treatment of IBD patients.

Assessment of extraintestinal manifestations in inflammatory bowel diseases: A systematic review and a proposed guide for clinical trials.

BACKGROUND AND AIMS: Extraintestinal manifestations are common in inflammatory bowel disease patients, although there are few data available on their diagnosis, management and follow-up. We systematically reviewed the literature evidence to evaluate tools and investigations used for the diagnosis and for the assessment of the treatment response in inflammatory bowel disease patients with extraintestinal manifestations. METHODS: We searched in PubMed, Embase and Web of Science from January 1999-December 2019 for all interventional and non-interventional studies published in English assessing diagnostic tools and investigations used in inflammatory bowel disease patients with extraintestinal manifestations. RESULTS: Forty-five studies (16 interventional and 29 non-interventional) were included in our systematic review, enrolling 7994 inflammatory bowel disease patients. The diagnostic assessment of extraintestinal manifestations was performed by dedicated specialists in a percentage of cases ranging from 60-100% depending on the specific condition. The clinical examination was the most frequent diagnostic strategy, accounting for 35 studies (77.8%). In patients with primary sclerosing cholangitis or rheumatological symptoms, biochemical and imaging tests were also performed. Anti-TNF agents were the most used biological drugs for the treatment of extraintestinal manifestations (20 studies, 44.4%), and the treatment response varied from 59.1% in axial spondyloarthritis to 88.9% in ocular manifestations. No benefit was detected in primary sclerosing cholangitis patients after treatment with biologics. CONCLUSIONS: In the clinical management of inflammatory bowel disease patients with extraintestinal manifestations the collaboration of dedicated specialists for diagnostic investigations and follow-up is key to ensure the best of care approach. However, international guidelines are needed to homogenise and standardise the assessment of extraintestinal manifestations.