Management of corneal complications in vernal keratoconjunctivitis: A review

Pediatric keratoconus

Keratoconus is a common pediatric corneal disease, leading to vision impairment and amblyopia. Compared to its adult counterpart, pediatric keratoconus has an advanced presentation, rapid progression, higher incidence of complications such as corneal hydrops, and greater potential impact on the quality of life. It typically manifests during puberty and can evolve rapidly to more severe stages if left untreated. This rapid progression underscores the importance of early diagnosis through regular screening in pediatric populations and vigilant monitoring of pediatric keratoconus suspects. Concomitant ocular allergies, ocular anomalies, systemic diseases (e.g. syndromes), and poor compliance with contact lenses might impede prompt intervention and frequently postpone rehabilitation. Corneal collagen crosslinking is a crucial intervention in the management of pediatric keratoconus because it strengthens the corneal microstructure and halts the disease progression. When conservative measures fail, keratoplasty remains a viable option with generally favorable outcomes, though with unique challenges in post-operative care, including concerns related to sutures, long-term graft survival and need for repeated examinations under anesthesia. A multidisciplinary approach involving ophthalmologists, optometrists, pediatricians, and other healthcare professionals, focusing on early diagnosis and timely intervention, is essential for the comprehensive management of pediatric keratoconus and to mitigate its impact on children's lives.

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.

Characteristics of Vernal Keratoconjunctivitis in Lhasa: A Single-Center, Observational Study

The incidence of vernal keratoconjunctivitis (VKC) varies across different ethnicities and regions. To investigate the clinical features of VKC in Tibet, a single-center case series of VKC was retrospectively reviewed from a general hospital in Lhasa over one year. General data and typical manifestations were recorded. Horner-Trantas dots, limbal neovascularization, pseudogerontoxon and upper palpebral conjunctival papilla were seen in most of these patients. Patients with signs such as limbal pannus (t = 2.18, P < 0.05), pseudogerontoxon (t = 2.61, P < 0.05), and Horner-Trantas dots (t = 2.33, P < 0.05) appeared to have longer disease courses, while patients with upper palpebral conjunctival lesions had earlier onset times (t = 2.12, P < 0.05). The clinical signs of VKC on the Tibetan Plateau are more obvious, and the ocular surface is commonly and severely involved.

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.

Quality assurance in corneal transplants: Donor cornea assessment and oversight

The cornea is the most frequently transplanted human tissue, and corneal transplantation represents the most successful allogeneic transplant worldwide. In order to obtain good surgical outcome and visual rehabilitation and to ensure the safety of the recipient, accurate screening of donors and donor tissues is necessary throughout the process. This mitigates the risks of transmission to the recipient, including infectious diseases and environmental contaminants, and ensures high optical and functional quality of the tissues. The process can be divided into 3 stages: (1) donor evaluation and selection before tissue harvest performed by the retrieval team, (2) tissue analysis during the storage phase conducted by the eye bank technicians after the retrieval, and, (3) tissue quality checks undertaken by the surgeons in the operating room before transplantation. Although process improvements over the years have greatly enhanced safety, quality, and outcome of the corneal transplants, a lack of standardization between centers during certain phases of the process still remains, and may impact on the quality and number of transplanted corneas. Here we detail the donor screening process for the retrieval teams, eye bank operators. and ophthalmic surgeons and examine the limitations associated with each of these stages.

Prevalence and risk factors of Vernal Keratoconjunctivitis among a Ghanaian clinical cohort: A case-control study

Background

Vernal Keratoconjunctivitis (VKC) has been determined to be highly prevalent in countries within the tropical climate region. However, little evidence from studies conducted within this region has been put forward to support this claim.

Aim

To determine the prevalence and risk factors of VKC among a Ghanaian clinical cohort.

Methods

A 3-year case-control study was conducted in a tertiary eye care institution, and medical records of patients who had been diagnosed of VKC between 2018 and 2021 were reviewed.

Results

Medical records of 3800 patients were reviewed. Some 359 cases of VKC were identified, with a population prevalence rate of 9.45 % . Males comprised 57.1 % of the population with VKC, with a male-to-female ratio of 1.33 : 1 . The disease was more prevalent (40.8%) in children (≤ 17 years), and the overall odds of incidence decreased by 10% for a unit increase in age. Age and sex-adjusted models revealed significant positive associations between Keratoconus [aOR = 40.760, 95% CI -5.948 to 339.937], Rhinitis [cOR = 5.183, 95% CI -2.074 to 12.022] and VKC. However, the incidence of VKC was relatively less expressive among pterygium cases [cOR = 0.315, 95% CI -0.077 to 0.846].

Conclusion

VKC is highly prevalent among children and is often associated with comorbidities of atopic origin that exacerbate the impact of the disease among this vulnerable population. It is imperative that clinicians provide holistic care for children with VKC.

Atopic Disease as a Risk Factor for Recurrent Herpetic Keratitis

Recurrent herpetic keratitis is a leading cause of blindness worldwide. In this population-based cross-sectional study, the medical records of Israeli adolescents and young adults who underwent systematic preconscription evaluation for mandatory military service were reviewed. The prevalence of atopic conjunctival disease was evaluated in cases with and without documented recurrent herpetic keratitis. The association was tested using uni- and multivariant analyses. Overall, 940,892 adolescents and young adults were included. The mean age was 17.57 ± 1.50 years (range 16-20 years), and 40.70% of participants were female. Recurrent herpetic keratitis was documented in 160 cases, with a prevalence of 0.017% in this age group. Compared to the general population, patients with recurrent herpetic keratitis were significantly more likely to be males (p = 0.003) with a concomitant diagnosis of atopic conjunctival disease (p < 0.0001). Patients with atopic conjunctival disease were 10.60-fold more likely to experience recurrent herpetic keratitis (95% confidence interval (CI): 6.76-16.64, p < 0.0001). Upon multivariate analysis, the results remained significant (p < 0.001). Cases of severe atopic conjunctival disease were more prone to recurrent HSV keratitis compared to mild cases (p < 0.001). These findings suggest that the timely appropriate treatment of atopic conjunctival disease may help reduce the frequency and severity of recurrent HSV keratitis and its complications.

A nerve-goblet cell association promotes allergic conjunctivitis through rapid antigen passage

The penetration of allergens through the epithelial layer is the initial step in the development of allergic conjunctivitis. Although pollinosis patients manifest symptoms within minutes after pollen exposure, the mechanisms of the rapid transport of the allergens remain unclear. In the present study, we found that the instillation of pollen shells rapidly induces a large number of goblet cell-associated antigen passages (GAPs) in the conjunctiva. Antigen acquisition by stromal cells, including macrophages and CD11b+ dendritic cells, correlated with surface GAP formation. Furthermore, a substantial amount of antigen was transported to the stroma during the first 10 minutes of pollen exposure, which was sufficient for the full induction of an allergic conjunctivitis mouse model. This inducible, rapid GAP formation and antigen acquisition were suppressed by topical lidocaine or trigeminal nerve ablation, indicating that the sensory nervous system plays an essential role. Interestingly, pollen shell-stimulated GAP formation was not suppressed by topical atropine, suggesting that the conjunctival GAPs and intestinal GAPs are differentially regulated. These results identify pollen shell-induced GAP as a therapeutic target for allergic conjunctivitis.

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.

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.

Surgical Treatment of Corneal Shield Ulcer in Vernal Keratoconjunctivitis: A Systematic Review

BACKGROUND

Vernal keratoconjunctivitis (VKC) severely affects the quality of life of affected patients. The development of a shield ulcer is considered one of the most severe late-stage complications, which when untreated leads to irreversible vision loss. In this systematic review, we outlined the results of surgical treatments of corneal shield ulcers in VKC.

METHODS

We searched 12 literature databases on 3 April 2023 for studies of patients with VKC in which shield ulcers were treated by any surgical treatment. Treatment results were reviewed qualitatively. Assessments of the risk of bias of individual studies were made using the Clinical Appraisal Skills Programme.

RESULTS

Ten studies with 398 patients with VKC were eligible for the qualitative review. Two categories of surgical approaches were described: supratarsal corticosteroid injection and debridement with or without amniotic membrane transplantation. Almost all patients experienced resolution or improvement of their shield ulcers, regardless of treatment modality. Time to healing was faster with surgical debridement. A small proportion experienced recurrence and side effects.

CONCLUSIONS

Surgical treatment for shield ulcers in VKC seems highly effective, but careful post-operative treatment and follow-ups are necessary due to the risk of recurrence and potential side effects.

Association between Dupilumab and Conjunctivitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Conjunctivitis is commonly reported in dupilumab users with atopic dermatitis (AD), and few studies have compared the risk of conjunctivitis among patients with different indications. This study aimed to investigate the association between dupilumab and conjunctivitis in various diseases. The protocol of this study was registered on PROSPERO (ID CRD42023396204). The electronic search of PubMed, Embase, Cochrane Library, and ClinicalTrials.gov was conducted for the period from their inception to January 2023. Only placebo-controlled, randomized controlled trials (RCTs) were included. The main outcome was the incidence of conjunctivitis during the study period. The subgroup analysis was performed for patients with AD and non-AD indications, which include asthma, chronic rhinosinusitis with nasal polyps, and eosinophilic esophagitis. In total, 23 RCTs involving 9153 patients were included for meta-analysis. Dupilumab users exhibited significantly higher risk of conjunctivitis (risk ratio [RR], 1.89; 95% confidence interval [CI], 1.34–2.67) than placebo users. Notably, significantly increased incidence of conjunctivitis was observed in the dupilumab group relative to the placebo group among patients with AD (RR, 2.43; 95% CI, 1.84–3.12) but not among patients with non-AD indications (RR, 0.71; 95% CI, 0.43–1.13). In conclusion, only dupilumab users with AD but not those with non-AD indications reported an elevated incidence of conjunctivitis.

Steroid-sparing effect of ciclosporin A 1 mg/mL: 5-year case series of 107 children and young people with vernal keratoconjunctivitis

Background/aims

To explore the steroid-sparing and other therapeutic effects of ciclosporin A (CsA) 1 mg/mL in the management of vernal keratoconjunctivitis (VKC).

Methods

Open retrospective single-group interventional consecutive cohort study (case series) of 107 children and young people (CYP) age 4.4–18 years with severe and/or recurrent VKC who were prescribed CsA 1 mg/mL between November 2015 and May 2021 at one institution. Review of electronic patient records, noting clinical indication for prescribing CsA 1 mg/mL, dosage prescribed at initiation and follow-up, impact on steroid usage before and after commencing CsA as well as adverse events and indications for discontinuation of treatment.

Results

The median number of inflammatory episodes requiring treatment with topical corticosteroids fell from 3 (IQR 2–4) during the 12 months prior to CsA 1 mg/mL to 1 (IQR 0–3) during the 12 months after, excluding steroid prescriptions with the first CsA 1 mg/mL prescription (Wilcoxon signed ranks test, two tailed, p<0.01). In the 12-month period following initiation of CsA 1 mg/mL with concomitant prescription of topical corticosteroids (n=82), daily dosage of steroids was reduced in 79 (96.3%) and discontinued in 67 (81.7%). The median number of hospital clinic visits fell from 4 (IQR 3–5) to 3 (IQR 2–5) (Wilcoxon p<0.01). Adverse events leading to discontinuation of CsA 1 mg/mL within 12 months of starting included stinging (instillation site pain) (6/107, 5.6%) and skinrash (1/107, 0.9%).

Conclusion

Commercial preparations of CsA 1 mg/mL, licensed for severe VKC in CYP, significantly reduce the need for concomitant topical corticosteroids and hospital clinic visits. Adverse events which may lead to discontinuation are stinging and skin rash.

The multifaceted aspects of ocular allergies: Phenotypes and endotypes

Like the lung, skin, and nose, the external eye is a common target of allergic inflammation. Ocular allergy (OA) represents a collection of underestimated diseases of the eye observed in children and adults. The ocular manifestations are the expression of multifactorial immune mechanisms that generally have a good prognosis, but for a few patients, long term inflammation may remarkably reduce the visual function. Evidence suggests that other co-participant systems, including epigenetic, genetic, environmental, individual factors, sex hormones, and the central and autonomic nervous systems may influence the ocular response from distant sites. This is consistent with the concept that the eye is an organ fully integrated with the rest of the body and that the therapeutic approach should be holistic, dynamic, and personalized. For instance, androgens and estrogens binding to receptors on the ocular surface and the continuous cross-talking of neuromediators and growth factors with immune cells act to maintain the ocular surface homeostasis in response to environmental challenges. The immune system links and regulates the response of the ocular surface. Complex and incompletely understood mechanisms influence the innate and adaptive immune responses and generate different OA phenotypes and endotypes discussed in the present review.

Epithelial barrier dysfunction in ocular allergy

The epithelial barrier is the first line of defense that forms a protective barrier against pathogens, pollutants, and allergens. Epithelial barrier dysfunction has been recently implicated in the development of allergic diseases such as asthma, atopic dermatitis, food allergy, and rhinitis. However, there is limited knowledge on epithelial barrier dysfunction in ocular allergy (OA). Since the ocular surface is directly exposed to the environment, it is important to understand the role of ocular epithelia and their dysfunction in OA. Impaired epithelial barrier enhances allergen uptake, which lead to activation of immune responses and development of chronic inflammation as seen in allergies. Abnormal expression of tight junction proteins that helps to maintain epithelial integrity has been reported in OA but sufficient data not available in chronic atopic (AKC) and vernal keratoconjunctivitis (VKC), the pathophysiology of which is not just complex, but also the current treatments are not completely effective. This review provides an overview of studies, which indicates the role of barrier dysfunction in OA, and highlights how ocular barrier dysfunction possibly contributes to the disease pathogenesis. The review also explores the potential of ocular epithelial barrier repair strategies as preventive and therapeutic approach.

OUP accepted manuscript

The corneal epithelium serves to protect the underlying cornea from the external environment and is essential for corneal transparency and optimal visual function. Regeneration of this epithelium is dependent on a population of stem cells residing in the basal layer of the limbus, the junction between the cornea and the sclera. The limbus provides the limbal epithelial stem cells (LESCs) with an optimal microenvironment, the limbal niche, which strictly regulates their proliferation and differentiation. Disturbances to the LESCs and/or their niche can lead to the pathologic condition known as limbal stem cell deficiency (LSCD) whereby the corneal epithelium is not generated effectively. This has deleterious effects on the corneal and visual function, due to impaired healing and secondary corneal opacification. In this concise review, we summarize the characteristics of LESCs and their niche, and present the current and future perspectives in the management of LSCD with an emphasis on restoring the function of the limbal niche.

Clinical, histological and immunohistochemistry characteristics of cornea in the sequelae stage of chronic vernal keratoconjunctivitis

Purpose:

To report the clinical outcomes and histopathological and immunohistochemistry (IHC) features in eyes with the sequelae stage of vernal keratoconjunctivitis (VKC).

Methods:

Investigative study of corneal samples obtained following surgical intervention for vision restoration in four eyes of three patients with VKC. Patient 1 (an 11-year-old boy) had deep anterior lamellar keratoplasty in both eyes, Patient 2 (a 24-year-old male) underwent superficial keratectomy followed by penetrating keratoplasty, and Patient 3 (a 22-year-old male) underwent penetrating keratoplasty. The corneal samples retrieved after surgical intervention were assessed for histology features and immunohistochemistry (IHC) studies.

Results:

The grafts were clear till the follow-up of 2–18 months. Histopathology of all four corneal samples showed epithelial hyperplasia, absent Bowman layer, thick hyalinized stromal lamellae, vascularization, and chronic inflammatory cells such as lymphocytes and plasma cells. IHC showed strong expression of CK 3 in both eyes of Patient 1 and no expression in Patients 2 and 3. The marker for limbal stem cells, ABCG2, was absent in all four samples; however, p63α was expressed strongly in Patients 2 and 3, moderately in the right eye of Patient 1, and marginally expressed in the left eye of Patient 1.

Conclusion:

The eyes in the sequelae stage of VKC (having corneal scarring and 360° hypertrophied limbus) can be managed favorably with keratoplasty and amniotic membrane transplantation without allogenic/cadaveric stem cell transplantation. The expression of transient progenitor cells in the scarred corneas of VKC patients in the sequelae stage suggests that the limbal stem cell dysfunction is more likely partial and self-renewal of limbal stem cells is a plausibility in these eyes.

Vernal keratoconjunctivitis and keratoconus

PURPOSE OF REVIEW

Vernal keratoconjunctivitis (VKC) is a severe allergic inflammatory disease affecting the conjunctiva in children and young adults. Keratoconus (KC) is a progressive corneal disease characterized by thinning of the corneal stroma, increased and asymmetric corneal curvature, with a potential for significant visual deterioration and is one of the most common corneal complications of VKC. We aimed to review the association of these two diseases, with focus on the mechanisms, prevalence, natural history and treatment strategies of KC associated with VKC.

RECENT FINDINGS

KC is a common complication of VKC. KC prevalence can be as high as 26.8% among VKC patients, whereas abnormal corneal topography may appear in up to 71% of them. It is more severe and progresses faster in the setting of VKC (P < 0.05), with remarkable visual deterioration and with an increased need for keratoplasty. Crosslinking treatment and corneal transplantation appear to be as effective for KC patients with VKC as compared to the patients without VKC. However, postoperative complications are higher in patients with VKC and demand close monitoring, tight control of local inflammation and prompt awareness with consequent restrain of eye rubbing.

SUMMARY

Patients with VKC should be closely monitored for KC. Prompt recognition of VKC and KC allows tight control of KC pathogenesis mechanisms, timely management of KC progression and preservation of vision and quality of life of young patients.

Understanding Vernal Keratoconjunctivitis: Beyond Allergic Mechanisms

Vernal keratoconjunctivitis (VKC) is a chronic, recurrent, inflammatory disease of the cornea and conjunctiva mostly affecting boys in prepubertal age. VKC recurrence is characterized by intense symptoms of itching, redness, and photophobia associated with corneal damage, impairment of visual function, and quality of life. The pathogenesis of VKC has not yet been completely understood, and it is still controversial. In fact, VKC is considered an ocular allergic disease due to the involvement of immunoglobulin E, eosinophils, and mast cells, and of a lymphocyte T-helper type 2 reaction. However, approximately half of VKC patients have negative allergological history and testing, suggesting that other pathogenic mechanisms participate in VKC development and severity. Specifically, evidence suggests that genetic, endocrine, neuronal factors and an imbalance of innate immunity are involved in the pathogenesis of VKC. The purpose of this review is to summarize evidence on the pathogenic role of innate immunity, neuroimmune reaction, and hormonal changes in VKC. Increasing understanding of the pathogenic mechanisms behind VKC may lead to the identification of novel biomarkers for diagnosis and/or potential therapeutic targets in order to improve the management of this challenging condition.

Pollen shells and soluble factors play non-redundant roles in the development of allergic conjunctivitis in mice

PURPOSE

We aimed to clarify the role of particulate allergen exposure to the conjunctiva in the development of allergic conjunctivitis.

METHODS

We administered ragweed pollen suspension, pollen extract, pollen shell, particulate air pollutants, and their combinations to the mouse conjunctiva five days a week without prior sensitization. Clinical signs were scored. Histological changes, cellular infiltrations, mRNA expressions, lymph node cell recall responses, and serum immunoglobulin levels were assessed. Immune cell-depleting antibodies and ST2 knockout mice were used to investigate the cellular and molecular requirements.

RESULTS

Pollen suspension, but not the extract or shell alone, induced robust eosinophilic conjunctivitis, accompanied by a proliferative response of epithelial cells. A combination of pollen extract and shell completely restored eosinophil accumulation. In addition, eosinophilic conjunctivitis was induced by a mixture of particulate air pollutants and pollen extract. Mechanistically, eosinophil accumulation was ameliorated by deficiency of the IL-33 receptor ST2 and abolished by depleting CD4⁺ T cells. Pollen shells, but not the extract, induced IL-33 release from conjunctival epithelial cells in vivo.

CONCLUSIONS

Our results indicate the non-redundant roles for the allergens' particulate properties and soluble factors in the development of allergic conjunctivitis.

Immunopharmacology in Vernal Keratoconjunctivitis: Current and Future Perspectives

Vernal keratoconjunctivitis (VKC) is a complex and chronic, multifactorial Th2 cell-mediated chronic ocular surface inflammatory condition that typically affects predominantly male children in hot or warm climates. The primary symptom is intense ocular pruritus, often significant enough to affect activities of daily living. Clinical features differ from simple forms of allergic conjunctivitis in that they are more-or-less confined to the superior tarsus and limbus. There is also a risk of corneal involvement, which leads to irreversible vision loss in approximately 6% of patients. Right now, there is no standardized treatment protocol, and many of the currently available options are not effective in severe and recurrent cases. As such, it is imperative to understand this complex allergic immune response in order to identify future therapeutic targets. This review will focus on potential drug targets in VKC, with particular emphasis on immunomodulators and immunobiologic agents.

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.