Topical immunomodulators in the management of allergic eye diseases

Allergic Conjunctivitis: Review of Current Types, Treatments, and Trends

Allergic conjunctivitis is an allergen-induced immune response secondary to the binding of immunoglobulin-E (IgE) to sensitized mast cells. Approximately 40% of North Americans and 20% of the world's population are impacted by some form of allergy and it continues to increase in prevalence, especially among children. Specified IgE antibodies can be found in almost all cases of exposure to seasonal or perennial allergens. Activation and degranulation of mast cells lead to increased tear levels of histamine, tryptase, leukotrienes, cytokines, and prostaglandins. The release of these factors initiates the recruitment of inflammatory cells in the conjunctival mucosa, which causes the late-phase reaction. Signs and symptoms of ocular allergies include itching, tearing, chemosis, and hyperemia, which can lead to decreased productivity and poor quality of life. Many treatment options are available to improve symptoms, including, mast cell stabilizers, antihistamines, dual-acting agents, steroids, nonsteroidal anti-inflammatory drugs (NSAIDS), and other off-label treatment modalities. This review article provides an overview of different types of allergic conjunctivitis, its pathology and immunology, and recommended methods of treatment.

Applications of topical immunomodulators enhance clinical signs of vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC): a meta-analysis

PURPOSE

This meta-analysis aimed to review the safety and efficacy of topical cyclosporine A (CsA) and topical tacrolimus in allergic eye disease.

METHODS

A systematic search identified thirteen studies and a total of 445 patients for inclusion, making this the largest meta-analysis published on the subject. The current review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

Thirteen randomized control trials were included in the meta-analysis. Eleven studies used CsA as the treatment, and two used Tacrolimus. In total, 445 participants were included, of whom 76.6% were male. The mean age of participants across the included studies was 14 years. All studies reported clinical signs as evaluated by an examining clinician. Signs were usually assessed by anatomical region, with the most common regions being the conjunctiva and the cornea, and the most common signs assessed were hyperemia and papillae. Three studies accounted for more than 50% of the meta-analysis's weight. Effect size (d) ranged from - 2.37 to - 0.03, negative values favoring immunomodulators. Fixed Effect Meta-Analysis returned an SMD of - 0.81 (95% CI [- 0.98, - 0.65]). However, there was significant heterogeneity (I2 = 61%, Qw = 30.76) in the outcome measure (P = 0.0021); therefore, a random-effect meta-analysis was also completed in which the pooled SMD was - 0.98 (95% CI [- 1.26, - 0.69], τ2 = 0.16).

CONCLUSIONS

This study affirms the current scientific community's stance that immunomodulators effectively treat clinical signs, including blepharitis, conjunctival hyperemia, edema, papillae, and corneal damage in severe ocular allergic disease.

Vernal Keratoconjunctivitis: A Systematic Review

Vernal keratoconjunctivitis (VKC) is a chronic, bilateral corneal and conjunctival problem which typically presents in young individuals. VKC is characterized by itching, photophobia, white mucous discharge, lacrimation, foreign body sensation, and pain due to corneal involvement of shield ulcers. Vernal keratoconjunctivitis is categorized within ocular diseases. The diagnosis is clinical, as no sure biomarkers pathognomonic of the disease have yet been identified. The VKC therapy relies on different types of drugs, from antihistamines and topical steroids to cyclosporine or tacrolimus eye drops. In extremely rare cases, there is also the need for surgical treatment for the debridement of ulcers, as well as for advanced glaucoma and cataracts, caused by excessive prolonged use of steroid eye drops. We performed a systematic review of the literature, according to PRISMA guideline recommendations. We searched the PubMed database from January 2016 to June 2023. Search terms were Vernal, Vernal keratoconjunctivitis, and VKC. We initially identified 211 articles. After the screening process, 168 studies were eligible according to our criteria and were included in the review. In this study, we performed a systematic literature review to provide a comprehensive overview of currently available diagnostic methods, management of VKC, and its treatments.

Diagnostic approach and grading scheme for canine allergic conjunctivitis

BACKGROUND

In humans, allergic conjunctivitis is a well described disease. In contrast, allergic conjunctivitis has not received much attention from the veterinary community so far. Canine allergic conjunctivitis (cAC) is one of the possible manifestations associated with canine atopic dermatitis (cAD), being often underdiagnosed and undertreated. Our aim is to contribute to disease characterization and clinical stagingfor cAC severity.

RESULTS

A retrospective observational study including 122 dogs that underwent a complete ophthalmological and dermatological examinations and diagnosed with allergic conjunctivitis was conducted. A total of six ophthalmic clinical signs were considered for disease characterization and clinical staging: conjunctival hyperemia, chemosis, ocular pruritus, epiphora, seromucoid to mucopurulent discharge and keratitis, classified from 0 (absent) to 3 (severe). Scores comprised between 1-5 were considered mild, 6-10 moderate and 11-18 severe. The majority of dogs (64%) presented with moderate cAC followed by 24% of mild stages and only 12% of severe presentations. The severity of allergic conjunctivitis was not correlated to sex or age at the time of diagnosis and all presented with a bilateral form of the disease. Chemosis (84%), hyperemia (83%) and ocular pruritus (79%) was observed in 55% of the cases. Seromucoid to mucopurulent discharge (62%) and epiphora (69%) were less frequent, with keratitis being the least encountered clinical sign (15%). The degree of keratitis showed a positive correlation with both severity and chronicity of cAC (rho = 0.21-0.29, p ≤ 0.02)). Severity of cAD and cAD were not significantly correlated (p-value = 0.4).

DISCUSSION AND CONCLUSION

The triad hyperemia, chemosis and ocular pruritus, already known in human medicine to be a reliable way of diagnosing human allergic conjunctivitis, also proved to be important in cAC Mild forms of the disease may pass unnoticed, ocular pruritus being hard to assess in canine patients.The proposed standardized diagnostic approach and novel grading scheme for cAC may be of value for both veterinary ophthalmologists and dermatologists, as well as general practitioners.

Efficacy and Safety of 0.1% Cyclosporine versus 2% Cyclosporine in the Treatment of Severe Vernal Keratoconjunctivitis in Children

INTRODUCTION

Vernal keratoconjunctivitis (VKC) is an inflammatory condition in children that can cause severe eye complications. Treatment is based on corticosteroid therapy during flare-ups, then antihistamines and cyclosporine in calmer periods. The dosage and posology of cyclosporine are subject to debate.

METHODS

The aim of the study is to compare the evolution in symptomatic and clinical scores, and need for topical corticosteroid treatment in a population of children with severe VKC treated with two dosages of cyclosporine treatment (0.1% and 2%). Data were compiled on inclusion then every three months from March, with a total follow-up duration of 12 months. Data concerning patient evolutions and complications were collected for the two treatment groups.

RESULTS

The mean age of the 46 children was 8.8 ±2.4 years with age at onset of symptoms of 5.1 ± 0.9 years. The cohort was predominantly (65%) male. Corticosteroid dependence on inclusion was present in 52% of the children included. A significant improvement in the various symptomatic and clinical scores was observed following treatment with cyclosporine (0.1% and 2%). Use of topical corticosteroid treatment reduced from 19 drops per month on inclusion to 4 drops per month at 12 months. Safety was comparable for the two groups.

CONCLUSION

Treatments with cyclosporine 0.1% and 2% lead to a favourable evolution in clinical and symptomatic scores and reduced corticosteroid use. Cyclosporine 0.1% is an interesting alternative to the 2% dosage, particularly due to its availability and ease of handling.

Ocular Co-Morbidities of Atopic Dermatitis. Part II: Ocular Disease Secondary to Treatments

Treatments used for managing atopic dermatitis (AD) may have adverse ocular effects that permanently affect vision. The objective of this review is to raise awareness among dermatologists regarding the potential ocular adverse effects of various AD therapies, including corticosteroids, calcineurin inhibitors, an interleukin-4 receptor α (IL-4Rα) antagonist, and phototherapy. Pertinent potential short- and long-term risks of these therapies include elevations in intraocular pressure from use of topical corticosteroids and conjunctivitis from use of dupilumab. Since some of these adverse effects may not exhibit symptomatology until permanent vision impairment occurs, it is important for dermatologists to understand these risks and proactively ensure their patients are receiving appropriate measures to prevent them.

Mini-monoka stenting for patients with perennial allergic conjunctivitis

Purpose: To assess the effectiveness of mini-monoka (MM) stenting in treating patients with perennial allergic conjunctivitis (PAC) and punctal stenosis. Methods: A retrospective case analysis was performed on 20 patients (40 eyes) who suffered from PAC with punctal stenosis who underwent MM (FCI Ophthalmics, Pembroke, MA, USA) stenting. Results: Nineteen patients (95%) were females, with an age range of 19-66 years (average 40.6 ± 25.4 years). All 20 patients (100% of eyes) had signs of PAC and punctal stenosis. All 20 patients (40 eyes) had received previous topical treatment including steroids. Nineteen patients (95% of eyes) had significant improvement in their allergy symptoms (tearing and conjunctival inflammation) following MM stenting. Conclusions: Stenosis of the punctum may play a role in the relapsing symptoms in PAC. MM stenting is a simple, safe, effective, and relatively non-invasive treatment option for the management of PAC in the presence of punctal stenosis.

Immunomodulatory effects of tacrolimus (FK506) for the treatment of allergic diseases

Tacrolimus has been used to prevent allograft rejection and also used in kidney, liver and heart transplantations. Various preclinical and clinical studies demonstrated that Tacrolimus possess immunomodulatory and anti-inflammatory properties. The mechanism of action of Tacrolimus in allergic diseases involves calcineurin inhibition, and downregulation of T-cell reactivity, IgE degranulation, and its actions on mast cells, dendritic cells, basophils, eosinophils and inhibition of transcription of proinflammatory cytokines. Herein we reviewed the Pharmacotherapeutic mechanism of action of Tacrolimus in the prevention of asthma, atopic dermatitis, and allergic conjunctivitis.

Clinical implications of mast cell involvement in allergic conjunctivitis

The conjunctiva is a common site for the allergic inflammatory response due to it being highly vascularized, having constant exposure to environmental pollutants and allergenic pollens and having a unique conjunctival associated lymphoid tissue. The primary morbidity of anterior surface conjunctival disorders that include allergic conjunctivitis and tear film disorders is associated with its high frequency of involvement rather than its severity, although the more chronic forms can involve the cornea and lead to sight-threatening conditions. Ocular allergy is associated with IgE-mediated mast cell activation in conjunctival tissue leading to the release of preformed mediators including histamine and proteases and subsequent de novo formation of lipid-derived mediators and cytokines that trigger a cascade of cellular and molecular events leading to extensive migration and infiltration of inflammatory cells to the ocular surface. The trafficking of neutrophils, eosinophils, and lymphocytes to the ocular surface is due to establishing various chemokine gradients (mainly CCL11, CCL24, CCL5, MCP-3, and MCP-4), cell surface expression of adhesion molecules (such as VCAM-1 the ligand for VLA-4), and leukocyte adhesion to vascular endothelium. The release of preformed mediators underlies the acute ocular surface response while the secondary influx of inflammatory cells leading to the recruitment and activation of eosinophils and the subsequent activation of Th2 and Th1 lymphocytes at the level of the conjunctiva reflects the late-phase reaction.

An update on ocular allergy

PURPOSE OF REVIEW

The update reviews prevalence, classification, cause, and treatment options for allergic eye disease.

RECENT FINDINGS

The incidence of allergic eye disease is underreported but may affect almost all patients with allergic rhinitis. Increased rates of oculonasal symptoms have been reported in the United States resulting in significant economic expenditures. The spectrum of allergic conjunctivitis and its differential considerations include seasonal and perennial conjunctivitis, vernal and atopic keratoconjunctivitis, and giant papillary conjunctivitis. Patients with allergic conjunctivitis have classic immunoglobulin E-mediated pathophysiology and treatments directed at allergen avoidance, traditional pharmacotherapy with oral antihistamines, topical dual-acting antihistamine/mast cell stabilizer agents, and treatment of tear film dysfunction are first-line management strategies. Immunotherapy is an effective treatment option and refractory cases may require ophthalmology comanagement for consideration of topical ester-based corticosteroid therapy and consideration of topical immunomodulators.

SUMMARY

Ocular allergy involving specific modifiable and treatable environmental sensitizations is common and often underrecognized. It can impair quality of life to varying degrees. Some cases are quite refractory to management and may require multidisciplinary coordination of care between allergy and ophthalmology specialists. Understanding classification, triggers, and treatment options is important in designing the most appropriate patient-tailored management plans.

Topical cis-urocanic acid prevents ocular surface irritation in both IgE -independent and -mediated rat model

PURPOSE

Our purpose was to investigate the effect of locally administered cis-urocanic (cis-UCA) in two experimental models of allergic conjunctivitis.

METHODS

The compound 48/80 (C48/80)-induced ocular irritation model (IgE-independent) and the ovalbumin (OA)-induced ocular allergy model (IgE-mediated) were used to test and compare the effect of cis-UCA on dexamethasone, ketotifen and olopatadine. In the C48/80 model, clinical severity scoring from photographs, immunohistochemical analysis of nuclear Ki-67 antigen to quantify actively proliferating epithelial cells and of caspase-3 enzyme to identify apoptotic activity in the conjunctival tissue were used. In the OA model, an Evans Blue stain concentration of conjunctival tissue was used to evaluate vascular leakage due to allergic reaction.

RESULTS

The cis-UCA was well tolerated and effective in both the IgE-independent and -mediated rat models. Treatment with C48/80 caused conjunctival hyperaemia, which was significantly inhibited by ketotifen at the 6 h time point (p = 0.014) and by dexamethasone and cis-UCA 0.5% at 12 (p = 0.004) and 24 (p = 0.004) hour time points. In a comparison between the active drug treatments, only ketotifen showed a significant difference (p = 0.023) to cis-UCA treatment at the 1 h time point, otherwise there were no statistically significant differences between the active drugs. Ketotifen, dexamethasone and cis-UCA 0.5% significantly inhibited the C48/80-induced nuclear accumulation of Ki-67, without differences between the active treatment groups. In the OA model, cis-UCA 0.5% did not inhibit the vascular leakage of conjunctiva, whereas cis-UCA 2.5% of was at least equally effective compared to olopatadine, abolishing the allergic vascular leakage response almost completely.

CONCLUSIONS

The present findings in the two AC models suggest that cis-UCA might have anti-allergic potency both in immediate and delayed-type allergic reactions in the eye.

Comparison of clinical outcome with different treatment regimens in acute adenoviral keratoconjunctivitis

PurposeTo compare the clinical outcome with different treatment regimens in Acute Adenoviral Keratoconjunctivitis (AAK).MethodsThe records of 110 patients diagnosed as AAK in two tertiary eye care centers were evaluated retrospectively. The treatment regimen, follow-up duration, time until improvement of the symptoms, visual acuity, clinical findings, Schirmer's test and the Ocular Surface Disease Index (OSDI) score at the first day, first week and third week were recorded. The Kruskal-Wallis Test and Chi-square test were used for comparison of quantitative and categorical variables, respectively.ResultsForty six patients were receiving topical corticosteroids (Group 1), 32 topical 2% Cyclosporin A (CsA) (Group 2) and 32 only artificial tears (Group 3). Mean time until resolution of the symptoms was lowest in Group 1 (9.5±4.9 days) and highest in Group 3 (13.3±4.2 days)(p: 0.001). OSDI scores at the first and third weeks were highest in Group 3 (52.4±16.4 and 32.3±13.0) and lowest in Group 1 (41.0±21.3 and 23.9±13.2)(p: 0.01 and p: 0.009). At day 21, percentage of the patients with subepthelial infiltrates was the highest in Group 3 (63.4%) and lowest in Group 1 (42.5%).ConclusionsThe symptoms were less severe and had a shorter duration with topical corticosteroids and CsA when compared with palliative therapy. Topical 2% CsA may inhibit development of corneal subepithelial infiltrates when used in the acute phase of infection, similar to corticosteroids.

1,25(OH)2D3 and VDR Signaling Pathways Regulate the Inhibition of Dectin-1 Caused by Cyclosporine A in Response to Aspergillus Fumigatus in Human Corneal Epithelial Cells

Background

The objective of this study is to observe whether cyclosporine A (CsA) inhibits the expression of dectin-1 in human corneal epithelial cells infected with Aspergillus fumigatus (A. fumigatus) and to investigate the molecular mechanisms of the inhibition.

Methods

Immortalized human corneal epithelial cells (HCECs) were pretreated with 1,25(OH)₂D₃ and VDR inhibitor for 1 h, and then they were pretreated with CsA for 12h. After these pretreatments, the HCECs were stimulated with A. fumigatus and curdlan respectively, and the expression of dectin-1 and proinflammatory cytokines (IL-1β and TNF-α) were detected by RT-PCR, western blot and ELISA.

Results

Dectin-1 mRNA and dectin-1 protein expression increased when HCECs were stimulated with A. fumigatus or curdlan, and CsA inhibited the dectin-1 expression both in mRNA and protein levels specifically. Dectin-1 and proinflammatory cytokine expression levels were higher when HCECs were pretreated with VDR inhibitor and CsA compared to pretreatment with CsA alone, while dectin-1 and proinflammatory cytokine levels were lower when HCECs were pretreated with 1,25(OH)₂D₃ and CsA compared to pretreatment with CsA alone.

Conclusions

These data provide evidence that CsA can inhibit the expression of dectin-1 and proinflammatory cytokines through dectin-1 when HCECs are stimulated by A. fumigatus or curdlan. The active form of vitamin D, 1,25(OH)₂D_3, and VDR signaling pathway regulate the inhibition of CsA. The inhibition is enhanced by 1,25(OH)₂D₃, and the VDR inhibitor suppresses the inhibition.

Ocular itch associated with allergic conjunctivitis: latest evidence and clinical management

Allergic conjunctivitis is one of the most common allergic conditions worldwide. Its incidence is increasing due to changing climate, pollution, increased pollen loads, and the subject's heightened immunological sensitivity in response to these environmental changes. The pathophysiology predominantly involves immunoglobulin E-related mast-cell activation, with release of histamine and other mediators contributing to the propagation of the response by calling in other immune cells and further inflammation. This article presents the evolution of ocular allergy treatments, from vasoconstrictors, to antihistamines and mast-cell stabilizers, to the dual-acting agents, as well as corticosteroid and immunomodulatory options. Future targets for allergy treatment are also discussed.

In vitro study of cyclosporine A 0.05 % on primary and recurrent pterygium fibroblasts

To compare the cyclosporine 0.05 % exposure effect on fibroblasts from primary and recurrent pterygium. Primary culture of fibroblasts from primary and recurrent pterygium was performed until the third passage, which was exposed to cyclosporine 0.05 % in a group and the other remaining unexposed (control group), in triplicates. After 3, 6, 12, and 17 days of exposure the viable cell counting was performed by hemocytometer. The results were statistically analyzed using the technique of analysis of non-parametric variance model for repeated measures with three factors. There was a significant reduction in both fibroblast proliferation, in primary as in the recurrent pterygium cultures exposed to cyclosporine when compared not exposed cultures, with statistical significance (P < 0.05). Comparing primary and recurrent pterygium that received the drug, there was no significant difference in cell proliferation in relation to primary or recurrent pterygium. Cyclosporine 0.05 % is effective in inhibiting fibroblast proliferation in culture, both in primary and as in recurrent pterygium.