Ocular Surface Inflammatory Disorders Research Articles

Lessons Learned From Ocular Graft versus Host Disease: An Ocular Surface Inflammatory Disease of Known Time of Onset.

The ocular surface inflammatory disorders (OSIDs) comprise a group of conditions characterized by persistent inflammation of the ocular surface and adnexal tissues. Systemic autoimmune diseases and hypersensitivity reactions cause them, and, if left untreated, can result in severe inflammatory dry eye, corneal damage, and vision loss. Ocular graft-versus-host disease (oGVHD) forms part of the ocular surface inflammatory disease umbrella. It is a condition occurring after allogeneic hematopoietic stem cell or bone marrow transplantation, usually in chronic graft-versus-host disease. oGVHD can virtually affect any ocular adnexal tissue, especially the meibomian glands, and cause persistent inflammation, tissue fibrosis, and subsequent chronic, severe dry eye disease. Among the OSIDs, oGVHD has the particularity that it has a "time zero," meaning we know when the disease started. As such, preclinical models have leveraged this to investigate the molecular mechanisms involved in the damage oGVHD causes to the ocular surface. In oGVHD, establishing a "time zero" allows for predicting the clinical course and establishing adequate treatment. This is also possible because the inflammatory infiltration occurs in ocular surface tissues, which are readily accessible. Using oGVHD, we might be able to understand the immune response mechanisms in other OSIDs better (i.e., Sjögren syndrome, Stevens-Johnson syndrome, among others). This review presents an up-to-date overview of the pathogenesis, clinical presentation, and treatment of oGVHD. In addition, we will discuss the value of the "time zero" concept in the study of oGVHD.

Increased Anti-Inflammatory Therapeutic Potential and Progenitor Marker Expression of Corneal Mesenchymal Stem Cells Cultured in an Optimized Propagation Medium.

There is a huge unmet need for new treatment modalities for ocular surface inflammatory disorders (OSIDs) such as dry eye disease and meibomian gland dysfunction. Mesenchymal stem cell therapies may hold the answer due to their potent immunomodulatory properties, low immunogenicity, and ability to modulate both the innate and adaptive immune response. MSC-like cells that can be isolated from the corneal stroma (C-MSCs) offer a potential new treatment strategy; however, an optimized culture medium needs to be developed to produce the ideal phenotype for use in a cell therapy to treat OSIDs. The effects of in vitro expansion of human C-MSC in a medium of M199 containing fetal bovine serum (FBS) was compared to a stem cell medium (SCM) containing knockout serum replacement (KSR) with basic fibroblast growth factor (bFGF) and human leukemia inhibitory factor (LIF), investigating viability, protein, and gene expression. Isolating populations expressing CD34 or using siRNA knockdown of CD34 were investigated. Finally, the potential of C-MSC as a cell therapy was assessed using co-culture with an in vitro corneal epithelial cell injury model and the angiogenic effects of C-MSC conditioned medium were evaluated with blood and lymph endothelial cells. Both media supported proliferation of C-MSC, with SCM increasing expression of CD34, ABCG2, PAX6, NANOG, REX1, SOX2, and THY1, supported by increased associated protein expression. Isolating cell populations expressing CD34 protein made little difference to gene expression, however, knockdown of the CD34 gene led to decreased expression of progenitor genes. C-MSC increased viability of injured corneal epithelial cells whilst decreasing levels of cytotoxicity and interleukins-6 and -8. No pro-angiogenic effect of C-MSC was seen. Culture medium can significantly influence C-MSC phenotype and culture in SCM produced a cell phenotype more suitable for further consideration as an anti-inflammatory cell therapy. C-MSC show considerable potential for development as therapies for OSIDs, acting through anti-inflammatory action.

Immunobiologicals and ocular surface disease.

Immunobiologicals have surfaced to become a new cornerstone of treatment for a wide spectrum of inflammatory disorders with an immune basis. The targets have ranged from autoimmune conditions to transplantation, and now more into atopic inflammatory disorders with primary targets of asthma and atopic dermatitis. The clinical information garnered from these studies have provided an initial snapshot on the potential adverse effects of the immunobiologicals on the ocular surface as well as providing a potential opening of their use in the treatment of various chronic ocular surface and intraocular inflammatory disorders that have previously been relegated to limited therapeutic options primarily to the broad anti-inflammatory use of glucocorticosteroids. The use of immunobiologicals provides a more directed therapeutic approach to many of the ocular inflammatory disorders, as we continue to appreciate more of their underlying immunopathophysiology of ocular surface disorder,s including ocular allergy and tear film dysfunction.

Ocular Surface Inflammatory Disorders (OSID): A Collective of Systemic Etiologies Which Cause or Amplify Dry Eye Syndrome.

The ocular surface inflammatory disorders (OSID) are caused by systemic disorders that conduct a persistent inflammatory reaction in the ocular adnexal connective tissues, such as the conjunctiva, lacrimal gland (LG) and meibomian glands (MGs), which cause an inflammatory dry eye. The etiologies of OSID are a subset of systemic pathologies such as graft versus host disease, Sjögren’s syndrome, allergies, cicatrizing conjunctivitis, and more. These cause a purely inflammatory dry eye syndrome as a consequence of the persistent surrounding inflammation in the adnexal tissues, which is distinct from the age-related dry eye disease. A limitation toward management of these conditions is the lack of available biomarkers that can detect presence of inflammation and quantify damage on the conjunctiva and LG, even though these are considered to be drivers of the inflammatory milieu. The OSID and dry eye syndrome are caused by different immune cells which are not exclusively limited to T cell lymphocytes, but rather derive from an orchestrated multicellular immunologic response. Recognition of this syndrome is crucial to direct research in a direction that clarifies the potential role of inflammation and its associated immune phenotype on the conjunctiva and adnexal ocular tissues in OSID and dry eye syndrome. On this paper, we review the basic and clinical research evidence for the existence of OSID with focus on the different immune cells involved, the target tissues and potential consequences and OSIDs diagnostic and therapeutic implications.

Use of Systemic Mycophenolate Mofetil Therapy in Ocular Surface Inflammatory Pathologies at the Initiative and Responsibility of the Ophthalmologist.

The purpose of the study was to evaluate the efficacy and safety of systemic mycophenolate mofetil (MMF) treatment in ocular surface inflammatory diseases. For this retrospective study, patients who were treated with systemic MMF for ocular surface inflammatory diseases between March 2020 and March 2022 were evaluated. Apart from demographic data, examination notes including MMF treatment indication and systemic side effect interrogation and routine laboratory examinations during drug treatment were extracted from the patient records. Detailed staging scores were performed according to the diagnosis including Foster and Mondino for ocular mucous membrane pemphigoid (MMP) and limbal stem cell deficiency scoring for limbal transplantation. For thorough evaluation, anterior segment pictures were used. Fourteen patients were enrolled to the study, with a mean age of 58 ± 12. MMP (6, 42.8%) and limbal allograft transplantation (6, 42.8%) constituted the main indications for the MMF treatment, followed by keratitis-ichthyosis-deafness (KID) syndrome (1, 7.2%) and Mooren's ulcer (1, 7.2%). Five of six patients with MMP regressed according to both staging systems. Only one remained stable which was evaluated as Stage 3. Furthermore, while all limbal transplant groups (6) stabilized and showed regression according to the individualized limbal stem cell deficiency staging system with no rejection during follow-up. Furthermore, patients with Mooren's ulcer and KID syndrome showed control of the inflammation and stabilization after MMF treatment. No significant systemic side effects apart from constipation and nausea (3) were observed in patients whose routine laboratory tests were stable throughout the follow-up. MMF has the potential to be a valuable and safe systemic agent of first choice in the control of ocular surface inflammatory disorders, especially when topical treatment is not effective. With such studies, it is predicted that MMF may reach wider usage areas with the increase in its effectiveness and safety in its use for ocular surface inflammatory pathologies.

Cluster Analysis of Dry Eye Disease Models Based on Immune Cell Parameters - New Insight Into Therapeutic Perspective.

Dry eye disease (DED) can be represented as a display of disease in the mucosal part of the eye. It is quite distinct from the retinal side of the eye which connects with the neurons and thus represents the neuroimmunological disease. DED can occur either by the internal damage of the T cells inside the body or by microbial infections. Here we summarize the most common animal model systems used for DED relating to immune factors. We aimed to identify the most important immune cell/cytokine among the animal models of the disease. We also show the essential immune factors which are being tested for DED treatment. In our results, both the mechanism and the treatment of its animal models indicate the involvement of Th1 cells and the pro-inflammatory cytokine (IL-1β and TNF-α) related to the Th1-cells. The study is intended to increase the knowledge of the animal models in the field of the ocular surface along with the opening of a dimension of thoughts while designing a new animal model or treatment paradigm for ocular surface inflammatory disorders.

Potential of mesenchymal stem cells as topical immunomodulatory cell therapies for ocular surface inflammatory disorders.

Ocular surface inflammatory disorders (OSIDs) are a group of highly prevalent, heterogeneous diseases that display a variety of aetiologies and symptoms and are risk factors for serious complications, including ocular and cornea impairment. Corneal inflammation is a common factor of all OSIDs, regardless of their cause or symptoms. Current medications include over‐the‐counter lubricating eye drops, corticosteroids, and ciclosporin, which either do not treat the corneal inflammation or have been associated with multiple side effects leading to alternative treatments being sought. Regenerative medicine cell therapies, particularly mesenchymal stem cells (MSCs), have shown great promise for immunosuppression and disease amelioration across multiple tissues, including the cornea. However, for successful development and clinical translation of MSC therapy for OSIDs, significant problems must be addressed. This review aims to highlight considerations, including whether the source of MSC isolation impacts the efficacy and safety of the therapy, in addition to assessing the feasibility of MSC topical application to the cornea and ocular surface through analysis of potential scaffolds and cell carriers for application to the eye. The literature contains limited data assessing MSCs incorporated into scaffolds for corneal administration, thus here we highlight the necessity of further investigations to truly exploit the potential of an MSC‐based cell therapy for the treatment of OSIDs.

The Innate Immune Cell Profile of the Cornea Predicts the Onset of Ocular Surface Inflammatory Disorders.

Ocular surface inflammatory disorder (OSID) is a spectrum of disorders that have features of several etiologies whilst displaying similar phenotypic signs of ocular inflammation. They are complicated disorders with underlying mechanisms related to several autoimmune disorders, such as rheumatoid arthritis (RA), Sjögren’s syndrome, and systemic lupus erythematosus (SLE). Current literature shows the involvement of both innate and adaptive arms of the immune system in ocular surface inflammation. The ocular surface contains distinct components of the immune system in the conjunctiva and the cornea. The normal conjunctiva epithelium and sub-epithelial stroma contains resident immune cells, such as T cells, B cells (adaptive), dendritic cells, and macrophages (innate). The relative sterile environment of the cornea is achieved by the tolerogenic properties of dendritic cells in the conjunctiva, the presence of regulatory lymphocytes, and the existence of soluble immunosuppressive factors, such as the transforming growth factor (TGF)-β and macrophage migration inhibitory factors. With the presence of both innate and adaptive immune system components, it is intriguing to investigate the most important leukocyte population in the ocular surface, which is involved in immune surveillance. Our meta-analysis investigates into this with a focus on both infectious (contact lens wear, corneal graft rejection, Cytomegalovirus, keratitis, scleritis, ocular surgery) and non-infectious (dry eye disease, glaucoma, graft-vs-host disease, Sjögren’s syndrome) situations. We have found the predominance of dendritic cells in ocular surface diseases, along with the Th-related cytokines. Our goal is to improve the knowledge of immune cells in OSID and to open new dimensions in the field. The purpose of this study is not to limit ourselves in the ocular system, but to investigate the importance of dendritic cells in the disorders of other mucosal organs (e.g., lungs, gut, uterus). Holistically, we want to investigate if this is a common trend in the initiation of any disease related to the mucosal organs and find a unified therapeutic approach. In addition, we want to show the power of computational approaches to foster a collaboration between computational and biological science.

Topical Application of TGF-β-Activating Peptide, KRFK, Prevents Inflammatory Manifestations in the TSP-1-Deficient Mouse Model of Chronic Ocular Inflammation.

Chronic inflammation of the ocular surface poses a risk of vision impairment. The understanding of the molecular mechanisms that are involved in the inflammatory response is critical to identify novel molecular targets. Recently, thrombospondin-1 (TSP-1) has emerged as a key player in ocular surface homeostasis that efficiently activates the TGF-β2 isoform that is predominantly expressed in the ocular mucosa. Here, the potential of the peptide derived from TSP-1 (KRFK), that can activate TGF-β, is proposed as a potentially applicable therapeutic for chronic ocular surface inflammatory disorders. Our in vitro results confirm that the chosen peptide activates TGF-β, reducing the expression of co-stimulatory molecules on dendritic cells, driving them towards a tolerogenic phenotype. For the in vivo studies, the TSP-1−/− mouse is used as a pre-clinical model of chronic ocular inflammation. We observe that the topical application of KRFK alters the peripheral balance of effectors by reducing the proportion of pathogenic Th1 and Th17 cells while increasing Treg cell proportion in cervical lymph nodes. In line with these findings, the development of chronic ocular surface inflammation is significantly prevented in KRFK-treated TSP-1−/− mice, as assessed by clinical parameters and inflammatory cytokine expression in conjunctival and lacrimal gland tissues. Together, our results identify the KRFK peptide as a novel therapeutic option to prevent the development of chronic inflammatory manifestations of the ocular surface.

Immunological impression cytology of the conjunctival epithelium in patients with thyroid orbitopathy-related dry eye

Thyroid orbitopathy (TO) is an autoimmune disease that is complicated by ocular surface disorders, leading to discomfort. Dry eye is very prevalent in patients with TO. Recent studies on the pathogenesis of dry eye have focused on the inflammatory process, and some supporting evidence has been discovered. Because TO is a disorder of autoimmune origin, we assumed that the association between TO and dry eye is related to inflammation. Inflammation of the ocular surface in TO-related dry eye has not been well studied. In this study, we assessed cellular inflammation of the ocular surface and the cytokine profiles in patients with TO-related dry eye. Conjunctival impression cytology (CIC) was assessed with an immunofluorescent assay. TO-related dry eye was diagnosed by using the Schirmer test, tear break-up time, thyroid function, and clinical signs. CIC was combined with immunological staining of interleukin-1a (IL-1a), IL-1b, and IL- 6. The immunological impression cytology (IC) grade was compared to the clinical activity score of TO. All TO patients with dry eye were positive for IL-1a, IL-1b, and IL-6. However, the normal controls were also positive for IL-1a. A trend was observed between the clinical inflammatory score and immunological IC grade. This study was the first to delineate the immunological IC of TO-related dry eye. Our study aimed to investigate the pathogenesis of dry eye in TO. Our findings suggest that the conjunctival cytokines IL-1a, IL-1b, and IL-6 may play a role. The results of this study will be useful for future studies of additional inflammatory cytokines, and the levels of these cytokines could be used as an outcome to assess the efficacy of treatment, such as anti-cytokine or immunosuppression therapy, in patients with TO-related dry eye or other ocular surface inflammatory disorders.

In situ gelling ophthalmic drug delivery system: Formulation and evaluation

ABSTRACTDesigning a drug delivery system to target the eye is an interesting and challenging endeavor faced by scientists because of the critical and pharmacokinetically‐specific environment that exists in the eye. Topical administration of ophthalmic drugs is used to alleviate the symptoms and signs caused by ocular surface inflammatory disorders, to treat infections, for glaucoma or intraocular inflammation (uveitis). However, the responsiveness toward the conventionally developed drug delivery system is limited because of the presence of several types of barriers in the eye that impede the effective passage of many drugs leading to minimal dose absorption. Ion activated in situ gelling ocular systems undergo phase transition in the presence of cations (present in the tear fluid), thus enhancing the residence time of drug in the cornea. In the present study natural polysaccharides (pectin alone or in combination with sodium alginate) or a pectin derivative (thiolated pectin [TP] alone or in combination with sodium alginate) were used to formulate in situ gelling eye drops. The formulations were evaluated for their gelling capacity, rheological studies, spreadability, bioadhesion strength, and in vitro drug release. Thiolation of pectin was observed to result in an increase in the gelling behavior, viscosity, and bioadhesive strength. The formulations comprising pectin alone (P7), combination of pectin and sodium alginate (P5SA1) or TP6 demonstrated good in vitro release characteristics. The optimized formulations displayed a significant decrease in the intraocular pressure as compared to the marketed formulation upon instillation in rabbit eye. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39788.

Prostaglandin E Receptor 4 Expression in Human Conjunctival Epithelium and Its Downregulation in Devastating Ocular Surface Inflammatory Disorders

Prostaglandin E Receptor 4 Expression in Human Conjunctival Epithelium and Its Downregulation in Devastating Ocular Surface Inflammatory Disorders

Suppressive Effects of Azithromycin on Zymosan-Induced Production of Proinflammatory Mediators by Human Corneal Epithelial Cells

In addition to its antibiotic effects, azithromycin has been noted to have anti-inflammatory activity, particularly in the context of microbial infections. This study was conducted to explore the suppressive effects of azithromycin on the production of proinflammatory mediators by human corneal epithelial cells (HCECs) stimulated by a fungal component, zymosan. Primary HCECs were cultured from donor corneal limbal explants and grown to subconfluence. The cells were treated with toll-like receptor (TLR) 2 agonist zymosan (1-50 μg/mL) for 4 to 48 hours, with or without preincubation with azithromycin (1-50 μg/mL), TLR2 antibody, or NF-κB activation inhibitor quinazoline (NF-κB-I). The cells were subjected to total RNA extraction, reverse transcription (RT), and real-time PCR using gene expression assays. Cells treated for 48 hours were used for immunofluorescence staining and Western blot analysis, and their medium supernatants were collected for protein quantitation by immunobead assays. The mRNA expression and protein production of proinflammatory cytokines (TNF-α and IL-1β), chemokines (IL-8 and RANTES), and matrix metalloproteinases (MMP-1, -3, and -9) by HCECs were stimulated by zymosan in a concentration-dependent manner, with peak levels noted at 4 hours. These stimulated levels of proinflammatory mediators by zymosan were significantly inhibited by TLR2 antibody, NF-κB-I, or azithromycin, which blocked zymosan-induced NF-κB activation as determined by p65 protein nuclear translocation. These findings demonstrated that the fungal component zymosan induces proinflammatory responses through TLR2 and NF-κB signaling pathways, whereas azithromycin suppresses its stimulation by blocking NF-κB activation in HCECs, suggesting the potential efficacy of this antibiotic for treating ocular surface inflammatory disorders.

Innate Immunity of the Ocular Surface and Ocular Surface Inflammatory Disorders

Ocular surface epithelial cells selectively respond to microbial components and induce limited inflammation, whereas immune competent cells such as macrophages can recognize various microbial components through Toll-like receptors (TLRs), induce inflammation, and, thereby, exclude microbes. The difference between macrophages and ocular surface epithelial cells could be due to their dissimilarity in coexistence with commensal bacteria. The unique innate immune response of the ocular surface epithelium might contribute to its coexistence with commensal bacteria. Moreover, we suspect that some ocular surface inflammatory disorders might be caused by abnormality of the mucosal innate immunity. We considered the possibility that there is an association between Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN)--a severe variant of SJS--and a disordered innate immune response. In gene expression analysis of CD14 cells, we found that interleukin-4 receptor (IL-4R) gene expression was different between patients with SJS/TEN and normal control subjects upon lipopolysaccharide (LPS) stimulation: it was downregulated in the former and slightly upregulated in the latter. Furthermore, expression of mRNA specific for IkappaBzeta and interleukin (IL)-1alpha was lower in patients with SJS/TEN than in normal controls after 1-hour culture. We next performed single nucleotide polymorphism (SNP) association analysis of IL-4R, IkappaBzeta, and IL1alpha genes and TLR2 and TLR3--genes associated with innate immunity--in 80 Japanese patients with SJS/TEN and 160 Japanese healthy volunteers. IL4R SNP Gln551Arg (rs.1801275) (P = 0.0004), TLR3 rs.3775296T/G SNP (P = 0.0001) and TLR3 rs.3775290A/G SNP (P = 0.009) showed a significant association with SJS/TEN. IkappaBzeta SNP rs.595788G/A showed a weak inverse association (P = 0.04). Genetic and environmental factors may play a role in an integrated etiology of SJS/TEN, and there is possibly an association between SJS/TEN and a disordered innate immunity.

The Short-Term Effect of Topical Cyclosporine A 0.05% in Various Ocular Surface Disorder

Purpose: To evaluate the efficacy of topical cyclosporine A 0.05% (Restasis) in the treatment of dry eye symptoms caused by various ocular surface inflammatory disorders. Methods: Thirty?three patients with ocular surface diseases, including 17 with Sj?gren syndrome, 8 with meibomian gland dysfunction (MGD), 4 with Thygeson’s keratitis, and 4 with atopic keratoconjunctivitis (AKC) were treated with Restasis twice a day for 3 months. During follow?up, the symptom severity assessment (burning, itching, foreign body sensation, blurring, photophobia, and pain), TBUT (tear break?up time), Schirmer score, frequencies of artificial tear use, onset of symptomatic relief, subjective satisfaction score, and side effects were evaluated. Results: In patients with Sj?gren syndrome, foreign body sensation, blurring, photophobia, and pain were reduced after treatment, and the mean Schirmer score, TBUT increased and frequencies of artificial tear use decreased significantly. In patients with MGD, photophobia was reduced after treatment, TBUT and artificial tear use improved after 2 months, and the Schirmer score increased at 3 months. In patient’s with Thygeson’s keratitis, foreign body sensation and photophobia reduced, and the Schirmer score was increased at 3 months. No significant changes in symptoms, Schirmer score, or TBUT were observed in patients with Of all subjects, 55% reported symptomatic relief between 3 and 5 weeks after treatment. The mean satisfaction score after treatment was the highest for patients with Sj?gren syndrome. Two subjects reported a temporary burning sensation, and one subject quit using Restasis because of bitter taste and a burning sensation. Conclusions: Treatment with Restasis appeared to be effective in treating dry eye symptoms in patients with Sj?gren syndrome. It was shown to be partially helpful in patients with MGD and Thygeson’s keratitis, while it showed no beneficial effect in patients with AKC.

Characterisation of the Normal Conjunctival Leukocyte Population

Lymphoid cells are present in normal mucosal tissue as scattered cells or organised into MALT. Knowledge of the non-pathological conjunctival lymphoid tissue is a vital basis for the further study of ocular surface inflammatory disorders. Therefore, we used immunohistochemistry to examine the leukocyte population of tarsal and bulbar conjunctiva from normal patients with no ocular or systemic inflammatory disease.CD3+T cells were the most frequently occurring, and macrophages the second most frequently occurring, conjunctival cell type and were seen in the epithelium and substantia propria. There were greater numbers of leukocytes in the bulbar than in the tarsal area and this reached statistical significance for CD3+T cells and CD57+NK cells. In both bulbar and tarsal conjunctiva, B cells and neutrophils were seen in the epithelium and substantia propria, but plasma cells, NK cells and mast cells were present only in the substantia propria. No eosinophils were seen. CD8+cells outnumbered CD4+cells in the epithelium (CD4:CD8 0.3) but this was reversed in the substantia propria (CD4:CD8 1.3 tarsal, 2.0 bulbar). Most epithelial T cells and half the stromal T cells were CD45Ro+. IL-2R (CD25) staining was infrequent in the tarsal but not the bulbar area. The greater number and activation of T cells in the bulbar region may relate to greater antigen exposure. HLA-DR+cells were mainly macrophages, but also included dendritic cells in the epithelium and a few epithelial cells. The conjunctival lymphocytes do have certain features of MALT cells, apart from mucosal recirculation, homing and promotion of sIgA production. Conjunctival IEL, like gut IEL, are predominantly CD8+, are found in the basal epithelium, are HML-1+, and have very high expression of CD45Ro. Substantia propria lymphocytes have more equal CD4 and CD8 numbers and frequently express CD45Ro. We found only one example of organised conjunctival lymphoid tissue in our study and suggest that the presence of CALT in humans is not universal.