Subcutaneous Allergen-specific Immunotherapy Versus Topical Treatment in Vernal Keratoconjunctivitis

Unraveling the complexity - Insights and interventions of refractory vernal keratoconjunctivitis

Vernal keratoconjunctivitis (VKC) is a chronic severe ocular allergic inflammation mostly observed in children and young adults. The ocular manifestations are the expression of multifactorial immune mechanisms that generally have a good prognosis, however long-term inflammation may remarkably reduce the visual function due to complications and poor therapeutic responses. Lack of responsiveness to a drug or treatment is relatively common in VKC and it is not only due to corneal involvement, which is considered the main sign of severity. The concept of refractory may be relative to multiple factors including the clinical condition, systemic co-morbidities, previous or concomitant drugs or regiments, compliance, patient's psychological condition or expectations, type of exposome and environmental conditions, doctor's experience and expectations, or timing of clinical evaluation. In this narrative review, the authors propose a definition of refractory VKC based on revised literature and clinical experience and consider potential new treatments for refractory patients and surgical management in case of complications.

Management of vernal keratoconjunctivitis: Navigating a changing treatment landscape

Vernal keratoconjunctivitis (VKC) is a chronic, progressive, and potentially sight-threatening form of ocular inflammatory disease that primarily affects children and young adults. Prevalence varies by region, ranging from <2 per 10,000 in the United States to as high as 1,100 per 10,000 in parts of Africa. The rarity of VKC in developed countries can make differential diagnosis challenging, and treatment is often delayed until the disease is advanced, and symptoms are significantly impacting patients' quality of life. Although once viewed primarily as an immunoglobulin E-mediated condition, approximately 50% of patients with VKC do not exhibit allergic sensitization. It is now recognized that the immunopathology of VKC involves multiple inflammatory pathways that lead to the signs, symptoms, and conjunctival eosinophilic and fibroproliferative lesions that are a hallmark of the disease. We examine the evolution of our understanding of the immunopathology of VKC, the expanding VKC treatment armamentarium, the clinical implications of emerging treatment approaches, and future directions for VKC research and practice.

Prevalence of allergic sensitization with vernal keratoconjunctivitis: A systematic review with meta-analyses

To determine the prevalence of allergic sensitization in patients with vernal keratoconjunctivitis (VKC) and to provide an overview of published studies on this topic. We systematically searched 11 literature databases on 24 May 2021, for studies with cross-sectional data on the prevalence of positive allergy tests in patients with VKC. Our main outcome of interest was the prevalence of allergic sensitization and the allergens involved. Prevalence meta-analyses were made to provide summary estimates. We identified 33 eligible studies for qualitative review with 2122 patients with VKC. Studies were predominantly based on patients seen in ophthalmology clinics. Overall, studies reported that the most prevalent positive allergen tests were the inhaled allergens house dust mites and pollen. Twenty-nine studies were eligible for the quantitative analysis. Here, we calculated the prevalence of allergen-positive patients to 57.7% (95% confidence interval: 52.5%-62.8%). Subgroup analyses of pooled estimates on sensitization based on specific testing methods found prevalence estimates of 51.4% for conjunctival provocation test, 68.7% for total tear IgE, 58.9% for specific tear IgE, and 58.2% for skin prick test. The prevalence of allergic sensitization in patients with VKC is 57.7%, and mostly towards inhaled allergens. The most frequent positive allergens are house dust mites and pollen. Identifying possible clinically relevant allergens provide information that may aid in managing VKC, such as environmental allergy-avoidance or allergy-specific treatment.

Comparative efficacy of medical treatments for vernal keratoconjunctivitis in children and young adults: a systematic review with network meta-analyses

PURPOSE

To systematically review the literature on the treatment of vernal keratoconjunctivitis (VKC) in children and young adults and conduct comparative efficacy analysis on clinical signs and symptoms using network meta-analyses.

METHODS

We systematically searched the databases PubMed/MEDLINE, EMBASE, Cochrane Central and Web of Science on 21 October 2019 for randomized controlled trials (RCT). Studies considered had patients with VKC < 20 years of age randomized into either intervention (any medical intervention) or comparator (active treatment, placebo treatment or non-treatment control), where pre-defined outcomes (data from ≥2 weeks and as close as possible to 2 months) of symptoms (itching, tearing, photophobia and foreign body sensation) and signs (hyperaemia, punctate keratitis, Horner-Trantas dots and macropapillae) were reported. Risk of bias within studies was evaluated using the Cochrane risk of bias tool. Comparisons were made using network meta-analyses.

RESULTS

We identified 39 studies with data on 2046 individuals. Twenty-three studies were eligible for quantitative analyses. None were systemic therapy. Temporal trend analysis showed that an initial focus on topical mast cell stabilizers turned to a focus on calcineurin inhibitors and a more diverse variety of pharmacological strategies. Studies varied in population, treatment duration and quality. The quantitative analysis revealed that efficacy of different therapies differed substantially across important clinical signs and symptoms, but there was a general trend of superior efficacy when using topical corticosteroids with stronger efficacy of the more potent corticosteroids.

CONCLUSION

We provide an overview of RCTs comparing the efficacy of treatments for VKC in children and young adults, which we find differs across symptoms and signs. Overall, we saw a general trend of superior efficacy with topical corticosteroids. However, our findings highlight the need for better studies, consensus on core outcomes and potential for individualized therapy.

Vernal Keratoconjunctivitis: Beyond the Classic Treatment

Vernal keratoconjunctivitis is a chronic allergic conjunctivitis with corneal involvement that affects children and adolescents. Its pathogenic mechanisms are not entirely clear, but IgE and other inflammatory mediators are involved. An 8-year-old boy with vernal keratoconjunctivitis not responding to conventional treatment started immunotherapy with good results, decreasing the topical steroid dependence. Conventional vernal keratoconjunctivitis treatment involves topical antihistamines and steroids. These are not always effective and steroids can be associated with severe ocular complications in the long term. The authors suggest searching for possible allergens and starting immunotherapy associated with conventional topical treatment earlier, in addition to measuring the health-related quality of life by applying the Quality of Life in Children with Vernal Keratoconjunctivitis questionnaire and adjusting the treatment according to the impact on patients' quality of life. [J Pediatr Ophthalmol Strabismus. 2021;58(5):e36-e39.].

Efficacy of medical treatments for vernal keratoconjunctivitis: A systematic review and meta-analysis

BACKGROUND

Vernal keratoconjunctivitis (VKC) is a severe type of allergic conjunctivitis for which treatment strategies are still under debate.

OBJECTIVES

This study sought to conduct a systematic review and meta-analysis to evaluate the efficacy of medical treatments for VKC.

METHODS

The PubMed, Cochrane Library, Embase, and ScienceDirect databases were searched to assess the efficacy of treatments for VKC. Random-effect meta-analyses on changes in clinical scores of symptoms and signs between baseline and after treatment, stratified on treatment classes, were computed. Meta-regressions were searched for potential influencing parameters.

RESULTS

Included were 45 studies (27 randomized controlled trials and 18 prospective cohort studies), 1749 patients (78% were men; mean age, 11.2 years), and 12 different treatment classes. Mast cell stabilizers (MCSs; usually considered as first-line therapy), cyclosporine, and tacrolimus were the most studied drugs (in three-quarters of studies). Overall, all clinical scores improved. Total symptom and sign score decreased for MCSs (effect size, -3.19; 95% CI, -4.26 to -2.13), cyclosporine (effect size, -2.06; 95% CI, -2.72 to -1.40), and tacrolimus (effect size, -2.39; 95% CI, -3.36 to -1.43). No significant differences were shown depending on treatment classes, concentration, age, sex, baseline activity scores, and atopy. Sensitivity analyses demonstrated similar results.

CONCLUSIONS

This study confirms the efficacy of MCSs in the treatment of VKC. Efficacy of cyclosporine and tacrolimus did not differ, suggesting that tacrolimus is a good alternative to cyclosporine for severe cases of VKC. Further studies are needed to compare other drugs and their precise place in treatment strategy.

Approaches toward enhancing survival probability following deep anterior lamellar keratoplasty

The greatest advantage of deep anterior lamellar keratoplasty over full-thickness corneal transplantation is the elimination of graft failure caused by endothelial rejection. Despite this advantage, a deep anterior lamellar keratoplasty graft can fail because of several factors, such as complications related to the donor-recipient interface, graft epithelial abnormalities, graft vascularization, stromal graft rejection, and recurrence of herpetic keratitis. Increased deep anterior lamellar keratoplasty graft survival is mainly built upon optimization of the ocular surface to provide a hospitable environment for the graft. Any predisposing factors for graft epithelial abnormalities, corneal neovascularization, and preexisting vernal keratoconjunctivitis should be identified and treated preoperatively. Prompt recognition and appropriate treatment of interface-related complications and stromal graft rejection usually result in good anatomic outcomes, with no detrimental effects on vision.

Vernal keratoconjunctivitis

Vernal keratoconjunctivitis (VKC) is a chronic allergic conjunctivitis that is most often seen in young, males. Although most types of allergic conjunctivitis do not affect vision, VKC is unusual in that damage to the cornea from the condition can result in vision loss. Although it is typically seasonal, year-round symptoms can be seen, which can lead to uncertain diagnoses being made. Although the pathophysiology of VKC is better understood in recent years, allowing more targeted therapies, management of these patients can still be very challenging, and complications can occur. As such, aggressive management of VKC is necessary, especially since vision loss in the amblyogenic age range can be permanent.

Selection of patients for sublingual versus subcutaneous immunotherapy

Allergen immunotherapy is the sole treatment for IgE-mediated allergic diseases directed at the underlying mechanism. The two widely accepted administration routes are sublingual (SLIT) and subcutaneous (SCIT). We reviewed how patients should best be selected for immunotherapy and how the optimal administration route can be defined. Before deciding SCIT or SLIT, appropriate selection of patients for allergen immunotherapy (AIT) is mandatory. To be eligible for AIT, subjects must have a clear medical history of allergic disease, with exacerbation of symptoms on exposure to one or more allergens and a corresponding positive skin or in vitro test. Then the route of administration should be based on: published evidence of clinical and immunologic efficacy (which varies per allergic disease and per allergen); mono- or multi-allergen immunotherapy, for SLIT multi-allergen immunotherapy was not effective; safety: adverse events with SLIT are more frequent, but less severe; and, costs and patient preferences, closely related to adherence issues. All these are discussed in the article.

Management of vernal keratoconjunctivitis

Vernal keratoconjunctivitis (VKC) is a relatively rare, chronic form of ocular allergy that can potentially cause severe visual complications. Affecting mainly children and young adults, it is an IgE- and T cell-mediated disease, leading to a chronic inflammation in which eosinophil, lymphocyte and structural cell activation are involved. Treatment of VKC requires a multiple approach that includes conservative measures and pharmacologic treatment. Patients and parents should be made aware of the long duration of disease, its chronic evolution and possible complications. Treatment should be based on the duration and frequency of symptoms and the severity of corneal involvement. Mast cell stabilizers and antihistamines have been proven to be effective for the treatment of mild to moderate forms of VKC. In the most severe cases, topical steroids can be used as rescue medication to reduce conjunctival and corneal inflammation. Immunomodulators that have been investigated for VKC treatment include topical ocular preparations of cyclosporine A and tacrolimus. Topical cyclosporine A has been proven to be effective in the long-term treatment of VKC, significantly improving signs and symptoms without significant side effects.