No apparent association between periocular and ocular microcolonization and the degree of inflammation in patients with atopic keratoconjunctivitis

Levofloxacin susceptibility of Staphylococci from conjunctiva in patients with atopic dermatitis

PURPOSE

The ocular surface in patients with atopic dermatitis (AD) is known to harbor an abundance of gram-positive cocci, particularly Staphylococcus aureus (S. aureus). This study reviewed the results of microbial cultures from the conjunctiva in AD patients, with special attention to the levofloxacin susceptibility of Staphylococci.

STUDY DESIGN

Retrospective, single-center study.

METHODS

This study involved 131 eyes of 112 Japanese patients with AD (87 men and 25 women, mean age: 40.4 ± 12.2 years) who underwent ocular surgery at Kyorin University Hospital. Bacterial isolates were collected from the conjunctival sacs in the preoperative period. Drug resistance to methicillin and levofloxacin was judged using the minimal inhibitory concentrations of oxacillin and levofloxacin determined by the broth dilution method.

RESULTS

One hundred and fifty-seven strains were identified in 103 of the 131 eyes examined. S. aureus was isolated from 74 eyes (56.5%), followed by Staphylococcus epidermidis (S. epidermidis). In S. aureus, 11 strains (14.9%) were methicillin-resistant, and 18 (24.3%) were levofloxacin-resistant. In S. epidermidis, 15 strains (26.8%) were methicillin-resistant, and 17 (30.4%) were levofloxacin-resistant. No significant differences were observed in levofloxacin susceptibility with age, sex, previous ocular surgery, or duration of previous surgery. However, logistic multivariate analysis revealed that levofloxacin-resistant Staphylococci were concurrently resistant to methicillin, suggesting multidrug resistance.

CONCLUSION

Distinctive bacterial distribution and drug resistance need consideration in the managing of ocular disorders among patients with AD.

Diagnostic criteria of chronic conjunctivitis: atopic keratoconjunctivitis and vernal keratoconjunctivitis

PURPOSE OF REVIEW

Chronic ocular allergies, vernal (VKC) and atopic keratoconjunctivitis (AKC) are relatively rare conditions that require definite diagnostic criteria to the most appropriate therapeutical approach.

RECENT FINDINGS

The diagnosis of both VKC and AKC is generally based on clinical history, signs and symptoms, and the results of allergic tests, which allow to identify the different diseases phenotypes. However, other subtypes of the two diseases and/or overlaps may occur making the diagnosis non always so clear, such as VKC and AKC overlaps or adult-like VKC disease. Each of these phenotypes may be sustained by different mechanisms which are still not well defined but not only related to a type 2 inflammation. The further challenges will be to correlate clinical or molecular biomarkers to a single subtype or disease severity.

SUMMARY

Definite criteria of chronic allergies will further guide to more specific therapeutical approaches.

Factors associated with ocular surface disease and severity in adults with atopic dermatitis: a nationwide survey

BACKGROUND

Ocular surface diseases (OSDs), including conjunctivitis and blepharitis, are common in atopic dermatitis (AD) patients, but the magnitude and patient characteristics are unclear.

OBJECTIVES

To examine the prevalence of OSDs in adults with AD and identify patient characteristics and risk factors.

METHODS

We designed a cross-sectional questionnaire-based survey and sent it via a secure public mail to all adult Danes with a hospital diagnosis of AD (ICD-10 code L20.x) registered in the National Patient Register (n = 16 718) between 2000 and 2019 and 7044 (42%) participated. Primary outcomes were OSDs and severity according to Ocular Surface Disease Index (OSDI). Adjusted odds ratios (aOR) were calculated with 95% confidence intervals (CIs) using logistic regression models.

RESULTS

Respondents were mostly females and middle-aged (67.4%, mean [SD] age, 39.0 [15.5] years). Based on Patient-Oriented SCORing Atopic Dermatitis 49% had mild AD, 35% moderate, 10% severe and in 6% AD was inactive; 44.3% reported physician-diagnosed asthma bronchiale and 55.8% rhinitis. The lifetime prevalence of OSDs was 66.6% for conjunctivitis, 63.5% for hordeolum, 11.0% for blepharitis, 9.7% for keratitis, 2.0% for pterygium, 1.5% for symblepharon, 1.1% for keratoconus and 12.7% reported current conjunctivitis. Factors associated with lifetime occurrence of conjunctivitis included mild, moderate, and severe AD (aOR = 1.48 [95% CI, 1.02-2.14], aOR = 1.73 [95% CI, 1.19-2.53], aOR = 2.17 [95% CI, 1.42-3.21]), asthma bronchiale and rhinitis (aOR = 1.76 [95% CI, 1.49-2.07]), childhood-onset of AD (aOR = 1.34 [95% CI, 1.16-1.56]) and systemic AD treatment (aOR = 1.27 [95% CI, 1.08-1.50]). Use of soft and hard contact lenses (aOR = 2.15 [95% CI, 1.65-2.80], aOR = 3.35 [95% CI, 1.62-6.92]) were associated with lifetime occurrence of keratitis. Moderate and severe AD, asthma bronchiale and rhinitis were also associated with a higher OSDI level.

CONCLUSIONS

This study identified important patient factors associated with OSDs. Clinicians should be attentive of ocular signs and symptoms in AD patients and ask about these.

Vernal keratoconjunctivitis: An update

Vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) are potentially severe and complex disease in its management among the various allergic eye diseases. In this regard, studies clarified the etiopathogenetic mechanisms. The workup should be multidisciplinary. The treatment includes topical and systemic medications with anti-inflammatory and immunosuppressant activity. However, a definition of nationally- and internationally-shared diagnostic protocols would also be needed and validated access to therapeutic options of proven safety and efficacy to avoid the use of galenic preparations, up to now still essential in the management of moderate-severe VKC. Finally, recognizing VKC and AKC, among rare diseases, at a national and international level would be an essential step to allow the management of VKC with adequate timings and settings within the National Health System.

Potential Biomarkers for Allergic Conjunctival Diseases

Allergic conjunctival diseases (ACDs) are a group of ocular allergies that include allergic conjunctivitis, atopic keratoconjunctivitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis. Although a large body of information exists on the pathophysiology of ACDs, this has not yet lead to the development of clear recommendations and guidelines for the diagnosis of ACDs or development of conclusive and objective diagnostic tools. Identification of objectively measurable biomarkers that represent the molecular and cellular mechanisms associated with ACDs will be an important step toward achieving these aims. This is a comprehensive review of biological markers that have the potential to become "biomarker(s)" for ACDs and aid in the classification, diagnosis, and development of new therapeutic strategies for these group of allergic conditions.

Ocular surface disease associated with dupilumab treatment for atopic diseases

Dupilumab is the first US FDA approved biologic for treatment of atopic dermatitis. It is a human monoclonal antibody which blocks the shared receptor component, the interleukin (IL)-4α subunit, of IL-4 and IL-13 signaling pathways. Occurrence of "conjunctivitis", mostly in atopic dermatitis trials, has been the main side effect reported thus far. The etiology of "conjunctivitis" associated with dupilumab treatment is unclear and might be similar to atopic keratoconjunctivitis. There is evidence in the published literature that unlike the Th2-like profile in vernal keratoconjunctivitis, Th1-mediated inflammation is predominant in atopic keratoconjunctivitis. Blocking the Th2 pathway with dupilumab therapy might result in a shift towards Th1, causing the ocular findings associated with dupilumab. In addition, blockage of IL-13 might have implications with regards to mucin production and ocular surface health. This review highlights the clinical manifestations, reviews treatment options and offers explanations for pathogenesis of this ocular surface diseases associated with dupilumab treatment.

Selected cytokine expression in dogs with alergic conjunctivitis: Correlation with disease activity

INTRODUCTION

Canine allergic conjunctivitis (cAC) is described as the most frequent ocular manifestation associated with canine atopic dermatitis (cAD).

OBJECTIVES

Clinical and immunological characterization of cAD through IL-6, TNF-α and IL-12 mRNA expression quantification in canine conjunctivae.

PROCEDURES

Twenty client-owned dogs with both cAC and cAD and twenty-one healthy controls were enrolled and clinician assessed CADESI-04 and grade of ocular signs were calculated. Conjunctival biopsies were performed on all animals and relative quantification of the interleukins mRNA expression performed by qRT-PCR. The correlation between cytokine gene expression and cAC score was evaluated, as well as CADESI-04 values.

RESULTS

The qRT-PCR showed a significant gene upregulation of respectively 291.48 (p = 1.306e-09) and 4.85 (p = .00033) folds on IL-6 and IL-12 in dogs with allergic conjunctivitis compared to the control group. Regarding the average expression of TNF-α there were no statistical significant differences between both groups (p = .18). Higher cAC scores were associated with enhanced gene expression of TNF-α and IL-12. No correlation was found between the cytokine gene expression levels and the CADESI-04 values.

CONCLUSION

An increase of IL6 and IL12 in cAC was found in the studied population. These two cytokines may be potential immunotherapy targets cAC classification.

Immunopathological Features of Severe Chronic Atopic Keratoconjunctivitis and Effects of Topical Cyclosporine Treatment

PURPOSE

To assess differential roles of inflammatory cells in pathophysiology of severe atopic keratoconjunctivitis (AKC) and evaluate immunomodulatory effects of topical cyclosporine A (CsA).

METHODS

A total of 10 patients with severe, steroid-dependent/resistant chronic active AKC were treated using frequent topical CsA 0.05% as monotherapy for 2 months. Conjunctival biopsy specimens before and after treatment were examined using immunohistochemistry. A total of 10 healthy age-matched adults served as the control group.

RESULTS

Baseline AKC samples revealed greater cluster of differentiation 4 (CD4), interferon gamma (IFNγ), human leukocyte antigen-D-related (HLA-DR) positive cell densities compared with healthy controls (P < 0.05), as well as interleukin (IL)-17 (P = 0.08). Topical CsA treatment induced a significant reduction in CD4 and IL-17 expressions (P < 0.05); post-treatment levels were same as normals (P > 0.05). Despite reduction after treatment (P = 0.06), HLA-DR expression remained higher than controls (P < 0.05).

CONCLUSIONS

AKC-related conjunctival inflammation appears to be mediated by delayed hypersensitivity. In this short-term trial, frequent topical CsA improved conjunctival inflammation.

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown.

Risk factors for contact lens-induced papillary conjunctivitis associated with silicone hydrogel contact lens wear

BACKGROUND

Contact lens-induced papillary conjunctivitis (CLPC) continues to be a major cause of dropout during extended wear of contact lenses. This retrospective study explores risk factors for the development of CLPC during extended wear of silicone hydrogel lenses.

METHODS

Data from 205 subjects enrolled in the Longitudinal Analysis of Silicone Hydrogel Contact Lens study wearing lotrafilcon A silicone hydrogel lenses for up to 30 days of continuous wear were used to determine risk factors for CLPC in this secondary analysis of the main cohort. The main covariates of interest included substantial lens-associated bacterial bioburden and topographically determined lens base curve-to-cornea fitting relationships. Additional covariates of interest included history of adverse events, time of year, race, education level, gender, and other subject demographics. Statistical analyses included univariate logistic regression to assess the impact of potential risk factors on the binary CLPC outcome and Cox proportional hazards regression to describe the impact of those factors on time-to-CLPC diagnosis.

RESULTS

Across 12 months of follow-up, 52 subjects (25%) experienced CLPC. No associations were found between the CLPC development and the presence of bacterial bioburden, lens-to-cornea fitting relationships, history of adverse events, gender, or race. Contact lens-induced papillary conjunctivitis development followed the same seasonal trends as the local peaks in environmental allergens.

CONCLUSIONS

Lens fit and biodeposits, in the form of lens-associated bacterial bioburden, were not associated with the development of CLPC during extended wear with lotrafilcon A silicone hydrogel lenses.

Ocular allergy: recognizing and diagnosing hypersensitivity disorders of the ocular surface

Ocular allergy includes several clinically different conditions that can be considered as hypersensitivity disorders of the ocular surface. The classification of these conditions is complex, and their epidemiology has not been adequately studied because of the lack of unequivocal nomenclature. Ocular allergy symptoms are often, but not always, associated with other allergic manifestations, mostly rhinitis. However, specific ocular allergic diseases need to be recognized and managed by a team that includes both an ophthalmologist and an allergist. The diagnosis of ocular allergy is usually based on clinical history and signs and symptoms, with the support of in vivo and in vitro tests when the identification of the specific allergic sensitization is required for patient management. The aims of this Task Force Report are (i) to unify the nomenclature and classification of ocular allergy, by combining the ophthalmology and allergy Allergic Rhinitis and its Impact on Asthma criteria; (ii) to describe current methods of diagnosis; (iii) to summarize the therapeutic options for the management of ocular allergic inflammation.

Conjunctival provocation with airborne allergen in patients with atopic keratoconjunctivitis

BACKGROUND

Atopic keratoconjunctivitis (AKC) is a chronic eye disease with periods of exacerbations. Many patients experience no obvious seasonal variation, although a majority of patients are allergic to common airborne allergens.

OBJECTIVE

To investigate the allergic reaction, to conjunctival provocation with airborne allergens, in patients with AKC.

METHODS

Eleven patients with AKC and birch and/or grass pollen allergy participated in the study, which was performed outside the pollen season. Five patients with seasonal allergic conjunctivitis (SAC) and five healthy subjects were included for validation purposes. The challenge was performed in one eye with the allergen, to which the patient was reactive, and with dilution buffer in the other eye. Signs and symptoms from both eyes were graded at baseline and at 10 min, 8 and 48 h after provocation. Tear fluid was collected from both eyes for cytokine analyses at baseline and at 8 and 48 h.

RESULTS

A significant change in clinical symptoms and signs, (redness and chemosis) was evident 10 min after provocation compared with baseline (P = 0.005) and compared with the unprovoked eye (P = 0.005) in AKC subjects. These parameters were normalized after 8 and 48 h. A significant increase for IFN-γ (P = 0.021) and IL-6 (P = 0.015), and a near significant increase for IL-10 (P = 0.066) were seen in the tear fluid of the challenged eye at 48 h after provocation vs. baseline and vs. the control eye for IFN-γ (P = 0.005), IL-6 (P = 0.028) and IL-10 (P = 0.008) in AKC subjects.

CONCLUSION AND CLINICAL RELEVANCE

In this single dose allergen provocation study, AKC patients responded with a typical IgE-mediated allergic reaction. An increase in cytokines at 48 h after the challenge was demonstrated and might, with further studies, give us a better understanding of the nature of inflammation in AKC.

Evaluation of the bacterial microflora of the conjunctival sac of healthy dogs and dogs with atopic dermatitis

The aim of this case-control study was to evaluate and compare the bacterial microflora from the conjunctival sac of dogs with atopic dermatitis and healthy dogs. Twenty-one atopic dogs without clinical and/or cytopathological signs of bacterial blepharoconjunctivitis and 21 breed-matched healthy dogs were enrolled. Under topical anaesthesia, the inferior conjunctival sac of one eye was scraped twice. Material was collected with a Kimura spatula, spread over a slide and stained with a Diff Quick(®) -type stain (Medion Diagnostics GmbH, Düdingen, Switzerland) for cytological examination. An area of 0.5 cm(2) was examined at ×1000 magnification, and the types and numbers of cells and bacteria were recorded. A bacterial swab was collected and inoculated into culture media for the growth of aerobic bacteria. Before sampling, each atopic dog was evaluated for severity of cutaneous lesions, pruritus and conjunctival inflammation. Significant differences were observed between atopic and healthy dogs for the presence of bacteria on cytology (P = 0.015), keratinized (P = 0.001) and nonkeratinized epithelial cells (P = 0.013), eosinophils (P = 0.019) and lymphocytes (P = 0.008). Bacteria were recovered from 12 atopic dogs and three healthy dogs (P = 0.004). Staphylococcus pseudintermedius was the most commonly isolated species in atopic dogs (seven of 12). In atopic dogs, no significant relation was found between conjunctival bacterial colonization (on cytology and culture) and the severity of any of the clinical parameters. This study suggests differences in conjunctival bacterial colonization and cytological features between atopic and healthy dogs.

Atopic dermatitis and keratoconjunctivitis

Atopic dermatitis, a chronic disease seen by allergist-immunologists, has both dermatologic and ocular manifestations. The ocular component is often disproportionately higher than the dermatologic disease. Even if skin abnormalities seem well controlled, these patients require ophthalmic evaluation. Atopic keratoconjunctivitis in atopic dermatitis patients is characterized by acute exacerbations and requires maintenance therapy for long-term control. Future studies will continue to emphasize the use of steroid-sparing, immunomodulating agents that have the potential to provide long-lasting anti-inflammatory control with a more favorable side-effect profile.

Cytokines and chemokines in immune-based ocular surface inflammation

Altered levels of several cytokines and chemokines have been found in different types of inflammatory ocular surface diseases, such as allergy or dry-eye syndrome. It has also been demonstrated that epithelial cells play a key role in the persistence and even initiation of chronic mucosal inflammation. The recent development of 'multiplex detection' technologies has facilitated the identification of specific patterns of expression of these molecules in some ocular immune-based inflammatory disorders. Analysis of these molecules in tissues, cells (in vivo and in vitro) and tears has revealed that not only inflammatory cells but also epithelial and fibroblast resident cells are sources of these molecules. The purpose of this review is to summarize recent studies in this field.

Evaluation of novel scoring system named 5-5-5 exacerbation grading scale for allergic conjunctivitis disease

BACKGROUND

The objective of this study is to evaluate the practical usefulness of a scoring system using the 5-5-5 exacerbation grading scale for allergic conjunctivitis disease (ACD).

METHODS

Subjects were 103 patients with ACD including 40 patients with vernal keratoconjunctivitis (VKC), 20 patients with atopic keratoconjunctivitis (AKC), and 43 patients with allergic conjunctivitis (AC). The 5-5-5 exacerbation grading scale consists of the following 3 graded groups of clinical observations: the 100-point-grade group (100 points for each observation) includes active giant papillae, gelatinous infiltrates of the limbus, exfoliative epithelial keratopathy, shield ulcer and papillary proliferation at lower palpebral conjunctiva; the 10-point-grade group (10 points for each observation) includes blepharitis, papillary proliferation with velvety appearance, Horner-Trantas spots, edema of bulbal conjunctiva, and superficial punctate keratopathy; and the 1-point-grade group (1 point for each observation) includes papillae at upper palpebral conjunctiva, follicular lesion at lower palpebral conjunctiva, hyperemia of palpebral conjunctiva, hyperemia of bulbal conjunctiva, and lacrimal effusion. The total points in each grade group were determined as the severity score of the 5-5-5 exacerbation grading scale.

RESULTS

The median severity scores of the 5-5-5 exacerbation grading scale in VKC, AKC and AC were 243 (range: 12-444), 32.5 (11-344), and 13 (2-33), respectively. The severity score of each ACD disease type was significantly different (P < 0.001, Kruskal-Wallis test). The severity of each type of ACD was classified as severe, moderate, or mild according to the severity score.

CONCLUSIONS

The 5-5-5 exacerbation grading scale is a useful clinical tool for grading the severity of each type of ACD.

Topical ophthalmic cyclosporine: pharmacology and clinical uses

Cyclosporine has been used successfully as a systemic immunomodulator for more than two decades, and numerous studies have investigated its mechanisms of action. In 2003 an ophthalmic formulation, cyclosporine 0.05% ophthalmic emulsion, was approved by the FDA to treat dry eye disease. Topical cyclosporine emulsion has also been investigated for treatment of other ocular surface disorders that may have an immune-based inflammatory component. In these trials, cyclosporine 0.05% ophthalmic emulsion has shown efficacy for management of posterior blepharitis, ocular rosacea, post-LASIK dry eye, contact lens intolerance, atopic keratoconjunctivitis, graft-versus-host disease, and herpetic stromal keratitis. As these disorders are often refractory to other available treatments, ophthalmic cyclosporine is a welcome nontoxic adjunct or replacement to potentially toxic topical or systemic immunosuppressive therapies.

Elevated Levels of Human α -Defensin in Tears of Patients with Allergic Conjunctival Disease Complicated by Corneal Lesions: Detection by SELDI ProteinChip System and Quantification

PURPOSE

To analyze levels of alpha -defensin in the tears of allergic patients (with/without corneal lesions) comparing the results with those of normal control subjects.

METHODS

Screening of the protein profiles of the tears of allergic patients with corneal epithelial lesions and normal controls was performed by surface enhanced laser desorption/ionization (SELDI) ProteinChip array initially. ELISA was then performed to quantify the levels of alpha -defensin in the tears of allergic patients (with/without corneal epithelial lesions) and normal control patients.

RESULTS

Proteins expressing significant differences between patients and controls by SELDI analysis were examined. Several peptides with molecular weights similar to alpha -defensins were found to be expressed to a greater extent in allergic patients. ELISA was performed in tears of allergic patients and control subjects to ascertain the presence and increased expression of alpha -defensins in allergic patients. Concentrations of alpha -defensins in allergic patients with corneal epithelial lesions were significantly higher than those of allergic patients without epithelial lesions or normal controls.

CONCLUSIONS

Alpha-defensins were found in greater concentrations in tears of allergic patients with corneal lesions. The antimicrobial effects of alpha -defensins may play a role in the prevention of secondary infection of corneal lesions in allergic patients. SELDI ProteinChip technology is a useful and effective tool in profiling the differential expression of proteins in tears.

Multiple cytokine analysis in human tears: an optimized procedure for cytometric bead-based assay

PURPOSE

To compare instruments and reagents used for cytometric bead-based assay (CBA) of cytokines in human tears.

METHODS

Two CBA instruments and reagent kits from five vendors were compared in parallel. Vendor protocols were modified to accommodate tear volumes. Precision, recovery, dilution linearity, and stability were evaluated.

RESULTS

Luminextrade mark and Bio-Radtrade mark proved optimal for tear CBA. Good correlation for dilution linearity was observed (r > 0.80, p < 0.05) for 1-4-mu l sample volumes. Samples were stable for 30 min at 25 degrees C.

CONCLUSION

Many tear cytokines can be reliably measured by CBA using an optimized protocol. Concentrations remain stable during periods consistent with collection.

Immunopathogenesis of ocular allergy: a schematic approach to different clinical entities

PURPOSE OF REVIEW

The immunopathogenesis of ocular allergic disorders is generally related to the specific immunoglobulin E-mediated mast cell activation and the following cascade of inflammatory mediators. Seasonal and perennial allergic conjunctivitis, however, are the only ocular diseases to involve solely type I hypersensitivity. The other main forms, vernal and atopic keratoconjunctivitis, have a more complex immunological basis and a chronic inflammatory component. Involvement of inflammatory cells, particularly eosinophils and T cells, cytokines and proteases can lead to more serious corneal damage with vision-threatening potential.

RECENT FINDINGS

Experimental allergic conjunctival models and clinical research studies have shown that T helper type 2-related mechanisms are definitely involved in the sensitization phase of ocular allergy, however, both T helper type 1 and type 2 cytokines are overexpressed in the active disease, contributing to the development of ocular inflammation.

SUMMARY

A review of the recent literature allows us to better understand the mechanisms involved in the development of ocular allergy and to guide us toward a more schematic approach, which could possibly be useful in forming a new classification, standardizing clinical phases and individuating new treatment targets.

Clinical grading of atopic keratoconjunctivitis

PURPOSE OF REVIEW

Atopic keratoconjunctivitis (AKC), the most severe and chronic form of ocular surface allergy-related disorder, is the ocular surface complication that some atopic dermatitis patients can suffer. Its wide range of severity, from mild and occasional problems to persistent and intense inflammation, makes it difficult to appropriately select uniform patients for clinical studies. This article proposes a new classification system for AKC based on clinical severity.

RECENT FINDINGS

Recent reports on AKC have contributed to a better understanding of the pathogenesis and clinical manifestations, and are offering new therapeutic candidates for AKC. No reports, however, have been found that address a classification of this disease.

SUMMARY

A new definition and classification for AKC is presented by this review, based on clinical severity, grading the main symptoms and signs. It intends to serve as a first forum of discussion among clinicians and other scientists working in the field of ocular surface inflammation. The final intention is to have a common language helping develop efficient clinical trials leading to successful approval of new therapeutic compounds for this blinding ocular surface condition.

Antibody array characterization of inflammatory mediators in allergic and normal tears in the open and closed eye environments

To evaluate the use of stationary phase protein array technology for tear analysis and to characterize the distribution of inflammatory mediators in normal and allergic tears in the open and closed eye states. Microcapillary tube collected Open (OTF) and closed eye tear fluid (CTF) samples from normals (N), from individuals with various active chronic ocular and other allergies (CA), as well as from an individual subsequent to unilateral induction of an acute allergic conjunctivitis were assayed using membrane arrays that were optimized to allow the detection of GM-CSF, ILs-1 alpha, 1 beta, 2-10, 12-13, INF gamma, MCP-1 and TNFalpha in clinical size samples. The protocol of a micro-well plate array specific for ILs-2, 4, 5, 8, 10, 12, 13, TNFalpha and INF gamma was modified to minimize the impact of tear matrix effects. This was used to carry out parallel analysis on selected samples. By optimizing the protocol as well as the composition of a membrane array it proved possible to significantly increase the signal-to-noise ratio and sensitivity of assay allowing for the detection of some inflammatory mediators into the sub-picogram range. This provided sufficient sensitivity to allow the assay of clinically obtainable size samples. Analysis revealed that OTF from most Ns contained a high level of IL-8 and faint signals if any for the other probed proteins. In contrast, OTF samples from most CA individuals with and without ocular symptoms exhibited to varying degrees detectable levels of most of the other probed entities. The difference between normal and pathological tears and the levels of signals became far more pronounced in the CTF compared to the OTF samples. Use of the micro-well plate assay kit without modification revealed two tear matrix effects that profoundly impact the ability to obtain meaningful ELISA data. Modifying the assay protocol reduces but does not eliminate these artifacts making it possible to approximate the concentration of many of the probed entities. The obtained data is consistent using both methodologies revealing elevated levels of IL-8 and other cytokines in approximately 60% of the OTF samples from the CA population. Other than a modest increase in IL-8, no change could be observed in the profile of OTF after induction of an acute allergic reaction.

Tacrolimus ointment vs steroid ointment for eyelid dermatitis in patients with atopic keratoconjunctivitis

AIMS

The main objective of this explorative study was to evaluate if tacrolimus ointment could be safer than corticosteroid ointment, with special reference to the intraocular pressure in the treatment of eyelid eczema in patients with atopic keratoconjunctivitis (AKC). Secondary aims were to compare the effects of the treatments on eyelid eczema and their potential impact on ocular surface inflammation.

METHODS

Tacrolimus 0.1% ointment and clobetasone butyrate 0.05% ointment were compared in a double-masked explorative crossover study. In total, 25 AKC patients were included. Each ointment was applied twice daily for 3 weeks, with 2 weeks of washout before, between, and after treatments. Efficacy was determined by eye examination and the patients' own symptom scoring. Cytology and cytokine measurements were performed on tear samples. Safety parameters were intraocular pressure, presence of bacteria and fungi, and the patients' reports of adverse events. The validity of the crossover design was explored with analysis of variance, and the effect of each medication was calculated with paired t-test and Wilcoxon paired test.

RESULTS

A total of 20 patients completed the study. Both treatments were effective in reducing signs and symptoms of eyelid eczema, with a near superior benefit for tacrolimus in terms of eczema (total skin score) signs (P=0.05). No serious adverse events occurred and interestingly, intraocular pressure was not evidently affected by either treatment.

CONCLUSION

Tacrolimus 0.1% ointment is a promising alternative therapy for eyelid eczema in AKC patients. Long-term studies are needed to further determine the value of tacrolimus in this patient group.

Differential diagnoses of conjunctivitis for clinical allergist-immunologists

OBJECTIVE

To provide a clinical overview of the types of conjunctivitis that are encountered by practicing clinical allergist-immunologists.

DATA SOURCES

Published literature in peer reviewed journals found in the National Library of Medicine (PubMed) database using the keywords ocular allergy and/or allergic conjunctivitis.

STUDY SELECTION

Studies related to ocular allergy and/or allergic conjunctivitis were selected for inclusion in this review.

RESULTS

Four clinical scenarios are presented that mimic frequently encountered inflammatory disorders that present as red eyes.

CONCLUSIONS

The signs and symptoms associated with the various inflammatory conditions affecting the conjunctiva often overlap and need to be differentiated to maximize care for patients with conjunctivitis.

Multiple cytokines in human tear specimens in seasonal and chronic allergic eye disease and in conjunctival fibroblast cultures

BACKGROUND

Several cytokines are involved in the recruitment and activation of inflammatory cells in ocular allergic diseases. The purpose of the study was to assay multiple cytokines and chemokines in tears, to compare subgroups of allergic conjunctivitis (AC) with controls, and in culture supernatants to determine whether conjunctival fibroblasts produce some of these cytokines.

METHODS

Fifty to one hundred microlitre tears were obtained from patients with active seasonal allergic conjunctivitis (SAC; n=12), vernal keratoconjunctivitis (VKC; n=18), atopic keratoconjunctivitis (AKC; n=6) and non-atopic controls (n=14). Primary conjunctival fibroblasts grown in vitro were stimulated with IL-4, IL-13 or TNF-alpha for 24 h. Cell-free tear and culture supernatants were assayed for IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, IFN-gamma, TNF-alpha, eotaxin, MCP-1 and RANTES using multiplex bead analysis. Induction of chemokine gene expression was determined by PCR.

RESULTS

IL-1beta, IL-2, IL-5, IL-6, IL-12, IL-13, MCP-1 were increased in all tears groups compared with controls, with highly significant correlations between many of these molecules. In addition IL-4, IFN-gamma, and IL-10 were elevated in SAC and VKC, while eotaxin and TNF-alpha were only increased in VKC. IL-6, IL-8, MCP-1, RANTES and eotaxin were detected from fibroblasts cultures, and were all up-regulated by TNF-alpha. By PCR, fibroblasts expressed MCP-1 transcripts constitutively, whereas IP-10 and Mig were up-regulated by TNF-alpha.

CONCLUSIONS

Differential cytokine levels support tears as a useful indicator of immune mechanisms occurring during AC. The striking similarities in chemokine profiles between tears and fibroblasts suggest these cells as likely sources of chemokines in tears.

Th1- and Th2-type cytokines in chronic ocular allergy

BACKGROUND

Previous reports have suggested that Th2-type cytokines are important in the pathogenesis of ocular allergic diseases. The purpose of this study is to measure levels and mRNA expression of Th1- and Th2-type cytokines in patients with active vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC).

METHODS

Tear samples and tear-isolated cells were obtained from 9 healthy participants (CT--controls), 28 VKC, and 6 AKC patients. IL-4, IL-13, and interferon gamma (IFNgamma) tear levels were determined by ELISA, and IL-4 and IFNgamma tear cell mRNA expression by RT-PCR. Effects of these cytokines on IL-6 and IL-8 secretion, and on ICAM-1 expression by conjunctival fibroblasts, were evaluated by ELISA and flow cytometry respectively.

RESULTS

Interleukin-4 tear levels were increased in VKC and AKC compared with CT, but only IFNgamma significantly correlated with corneal involvement. An IL-4/13-dominant profile was found in 50% of VKC and in 17% of AKC patients, while a IFNgamma-dominant profile was found in 18% of VKC and in 17% of AKC patients. IL-4 and IFNgamma transcripts were detected in tear cells from 11 out of 12 VKC patients. IFNgamma upregulated expression of ICAM-1 on conjunctival fibroblasts and the secretion of IL-6 and IL-8.

CONCLUSIONS

Although both IL-4 and IFNgamma are detected in tears, only IFNgamma levels correlated with disease severity and upregulated ICAM-1 on conjunctival fibroblasts, suggesting the role of IFNgamma in the inflammatory phase of chronic allergic eye diseases.

Allergic diseases of the eye

The prevalence of ocular allergy is clearly underappreciated; it has been an underdiagnosed and undertreated area in primary care medicine. The ocular symptoms associated with the most common ocular allergy conditions,such as seasonal and perennial AC, are twice as likely to affect the allergy sufferer as nasal symptoms alone. The emergence of new medications for the specific treatment of ocular symptoms over the course of the past 15 years offers a new field for improved patient care by the primary and sub-specialty health care providers.

In-vivo diagnostic measurements of ocular inflammation

PURPOSE OF REVIEW

The diagnosis of allergic conjunctival inflammation is usually made on the basis of clinical signs and symptoms; however, in-vivo and in-vitro tests are indicated when patient management requires identification of the specific allergic sensitization. The purpose of this review is to describe recent and less recent methods to assess ocular allergic inflammation.

RECENT FINDINGS

In the non-active phase of the disease, the specific conjunctival provocation test can be used to identify local sensitivities to allergens. Although not highly specific, total IgE in tears may be measured with a simple local test by inserting a paper strip in the lower meniscus. Limited tear volume prohibits the use of specific IgE tests. The measurement of tear-specific inflammatory markers, such as eosinophil cationic protein, IL-4, IL-5 and eotaxin, may also be useful for the diagnosis of ocular allergy. Multiple cytokine assays of tear samples and new imaging techniques are exciting advances that might provide the in-vivo diagnosis of ocular surface inflammation.

SUMMARY

Whereas chronic, severe ocular allergic conditions have uniquely diagnostic signs and symptoms, the most common diseases, seasonal and perennial allergic conjunctivitis, have no specific pathognomonic signs. The diagnostic measurements of local inflammation may help in the management of ocular allergy.

Toll-like receptor 2 expression on human conjunctival epithelial cells: a pathway for Staphylococcus aureus involvement in chronic ocular proinflammatory responses

BACKGROUND

Staphylococcus aureus colonization is common in atopic keratoconjunctivitis, potentially activating epithelial cells via toll-like receptor 2 (TLR-2) and the receptor for platelet-activating factor (PAFR).

OBJECTIVES

To examine human conjunctival epithelial cells for the expression of TLR-2 in vitro and in vivo and to evaluate the role of TLR-2 in S aureus-mediated activation of these cells.

METHODS

Conjunctival epithelial cells isolated from cadaveric tissues were stimulated with interferon gamma (IFN-gamma) or a commercial S aureus cell wall extract (Staphylococcus aureus-CWE) (with or without anti-TLR-2 blocking antibody or PAFR antagonist) and were analyzed for tumor necrosis factor alpha (TNF-alpha) and interleukin 8 (IL-8) release; surface expression of TLR-2, intercellular adhesion molecule-1, HLA, and CD14; and TLR-2 messenger RNA expression. Ocular surface cells collected via impression cytology were examined for TLR-2 expression via flow cytometry.

RESULTS

Expression of TLR-2 was up-regulated on conjunctival epithelial cells by IFN-gamma and Staphylococcus aureus-CWE. Expression of TLR-2 messenger RNA was increased by IFN-gamma. Staphylococcus aureus-CWE up-regulated intercellular adhesion molecule 1, HLA, and CD14 expression and increased TNF-alpha and IL-8 release in a dose-dependent manner. Anti-TLR-2 significantly inhibited TNF-alpha release, whereas PAFR antagonist significantly inhibited IL-8 release. Toll-like receptor 2 was expressed on conjunctival epithelial cells from 4 of 5 patients with atopic keratoconjunctivitis, 3 of 5 with seasonal allergies, and 0 of 3 without allergies.

CONCLUSIONS

Conjunctival epithelial cells express TLR-2 and may play an active role in the chronic ocular inflammatory response to S aureus through pathways that involve TLR-2 and PAFR.

Tear cytokines in acute and chronic ocular allergic inflammation

PURPOSE OF REVIEW

Elevated levels of inflammatory cytokines have been reported in tears from ocular allergic disease states. The purpose of this review is to assimilate recent research contrasting tear cytokine concentrations in non-allergic subjects versus subjects with acute (seasonal allergic conjunctivitis) and chronic (giant papillary conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis) ocular allergic inflammation to discover whether the cytokine profiles could provide useful insight into disease mechanisms and therapeutic targets.

RECENT FINDINGS

Recent studies have revealed distinct differences in the cytokine/chemokine concentrations in tears between the various manifestations of ocular allergy. The acute (seasonal allergic conjunctivitis) and iatrogenic (giant papillary conjunctivitis) forms of ocular allergic inflammation are characterized by an overall lack of significant cytokine changes in tears compared with chronic disease (vernal keratoconjunctivitis, atopic keratoconjunctivitis). Chronic ocular allergic inflammation produces increased concentrations of T helper 1 and 2, and proinflammatory cytokines as well as chemokines. However, vernal and atopic keratoconjunctivitis portray distinct differences in the patterns of tear cytokines/chemokines expressed.

SUMMARY

The plethora of increased cytokines and chemokines in vernal and atopic keratoconjunctivitis compared with non-allergic, seasonal allergic conjunctivitis and giant papillary conjunctivitis provides a new perspective into the complex inflammatory processes occurring on the ocular surface in chronic disease. The ability to measure multiple cytokines in tears, combined with knowledge obtained from in-vitro analysis of the individual and combined effects of these cytokines on various conjunctival cells (i.e. mast cells, epithelial cells, fibroblasts) has facilitated further understanding of specific processes contributing to maintenance of inflammation and progression of vision-threatening disease and paved the way toward new therapeutic targets.