Trends in prevalence and treatment of ocular allergy

Effects of common eye diseases in children and their treatment measures on ocular surface homeostasis: A review

Ocular surface homeostasis plays a vital role in maintaining of eye health. Dry eye disease is one of the prominent and typical manifestations of disruption of ocular surface homeostasis that leads to the worsening of ocular surface homeostasis that leads to the worsening of ocular surface disease when it interacts with other pathogenic factors. However, disruption in ocular surface homeostasis in children is often overlooked because of the current methods of assessing ocular surface homeostasis. This review summarizes the main factors affecting ocular surface homeostasis in children, with the aim of drawing the attention of clinicians to the disruption of ocular surface homeostasis in children when dealing with such diseases. Ocular surface homeostasis involves several interrelated components, each of which plays a nonnegligible role in ocular surface homeostasis. Unlike adults, children have a stronger lacrimal gland secretion capacity and milder symptoms when there is a slight disruption of the ocular surface homeostasis. In addition, children's expressive abilities were weaker. Therefore, dry eye in children is often ignored by doctors and parents, and clinicians should pay more attention to the protection of ocular surface homeostasis when treating children with these diseases. Therefore, there is a need for diagnostic criteria for dry eye disease specific to children.

Allergen-specific IgE in the tear fluid of Chinese patients with common allergic conjunctivitis in autumn and winter

PURPOSE

In this study, we determined the positive rates of allergen-specific immunoglobulin E (IgE) in the tear fluid of Chinese patients with common allergic conjunctivitis (AC) in autumn and winter, compared systemic and ocular allergen tests, and explored the correlation between the numbers and categories of allergens and clinical AC features.

METHODS

This cross-sectional study recruited 44 patients with AC (86 eyes). Specific IgEs for allergens common in China (house dust mite, cat/dog dander, mugwort/ragweed pollen, cottonwood/willow/elm pollen, milk, egg whites, soybeans) were measured in collected tears using kits for allergen-specific IgE antibodies. AC signs and symptoms were graded according to severity.

RESULTS

Specific IgE in tears was positive in 87.2% of eyes. House dust mite was the most common allergen (86.0%), followed by cat (24.4%) and dog (7.0%) dander; tree and grass pollen accounted for only 4.7% and 2.3%, respectively. Food allergens were not detected. The positive rates of the systemic allergen tests were lower than in tear fluid tests in both eyes, especially for house dust mites (P = 0.000). In patients with more allergens, itching was more severe (P = 0.035), while conjunctival hyperemia was milder (P = 0.002).

CONCLUSION

In autumn and winter, the most common AC allergen in Chinese patients was house dust mites. Compared with systemic allergen tests, measuring specific IgE in tears may be a non-invasive method to diagnose and evaluate AC severity, which may be more suitable to reflect the local conditions of ocular surface inflammation due to its high positive rate and convenience.

Effects of Punctal Occlusion on Ocular Itching and Conjunctival Redness Associated with Allergic Conjunctivitis

PURPOSE

Punctal occlusion using punctal plugs has been successfully used to treat the signs and symptoms of dry eye disease. However, the effects of punctal occlusion on the symptoms of allergic conjunctivitis (AC) have been less well documented. There is some concern among clinicians that punctal occlusion may make signs/symptoms of allergic conjunctivitis worse by trapping allergens on the eye. The objective of this post hoc analysis was to address this question and thus assess the effect of punctal occlusion alone on ocular itching and conjunctival redness associated with AC.

METHODS

This was a pooled post hoc analysis of three randomized, double-blind, placebo insert-controlled clinical trials in subjects with AC. Enrolled subjects were generally healthy adults with ocular allergies and a positive skin test reaction to perennial and/or seasonal allergens. The study used a modified version of the traditional conjunctival allergen challenge (CAC) model, which included multiple, repeated allergen challenges following placement of the intracanalicular insert. Subjects were rechallenged on Days 6, 7 and 8; Days 13, 14 and 15; and Days 26, 27 and 28.

RESULTS

The data set included 128 subjects that were administered placebo. Baseline mean (SD) ocular itching and conjunctival redness scores were 3.52 (0.44) and 2.97 (0.39), respectively. On post-insertion Days 7, 14 and 28, mean itching scores were 2.62, 2.26 and 1.91, respectively, representing 26%, 36% and 46% itching reductions, respectively (p < 0.001). On Days 7, 14 and 28, mean conjunctival redness scores were 1.98, 1.90, and 2.08, respectively, representing 33%, 36%, and 30% redness reductions, respectively (p < 0.001).

CONCLUSIONS

Based on this post hoc pooled analysis, punctal occlusion with a resorbable hydrogel intracanalicular insert did not worsen ocular itching or conjunctival redness in this patient population.

TFOS Lifestyle: Impact of contact lenses on the ocular surface

Several lifestyle choices made by contact lens wearers can have adverse consequences on ocular health. These include being non-adherent to contact lens care, sleeping in lenses, ill-advised purchasing options, not seeing an eyecare professional for regular aftercare visits, wearing lenses when feeling unwell, wearing lenses too soon after various forms of ophthalmic surgery, and wearing lenses when engaged in risky behaviors (e.g., when using tobacco, alcohol or recreational drugs). Those with a pre-existing compromised ocular surface may find that contact lens wear exacerbates ocular disease morbidity. Conversely, contact lenses may have various therapeutic benefits. The coronavirus disease-2019 (COVID-19) pandemic impinged upon the lifestyle of contact lens wearers, introducing challenges such as mask-associated dry eye, contact lens discomfort with increased use of digital devices, inadvertent exposure to hand sanitizers, and reduced use of lenses. Wearing contact lenses in challenging environments, such as in the presence of dust and noxious chemicals, or where there is the possibility of ocular trauma (e.g., sport or working with tools) can be problematic, although in some instances lenses can be protective. Contact lenses can be worn for sport, theatre, at high altitude, driving at night, in the military and in space, and special considerations are required when prescribing in such situations to ensure successful outcomes. A systematic review and meta-analysis, incorporated within the review, identified that the influence of lifestyle factors on soft contact lens dropout remains poorly understood, and is an area in need of further research. Overall, this report investigated lifestyle-related choices made by clinicians and contact lens wearers and discovered that when appropriate lifestyle choices are made, contact lens wear can enhance the quality of life of wearers.

Combination Therapy of 0.1% Fluorometholone and 0.05% Azelastine in Eyes with Severe Allergic Conjunctival Diseases: A Randomized Controlled Trial

This study sought to evaluate the efficacy of the isolated use of fluorometholone compared with the combined use of azelastine and fluorometholone for the treatment of severe allergic conjunctival disease (ACD). One hundred and eleven patients with severe ACD were randomized into two groups: one treated with topical 0.1% fluorometholone combined with 0.05% azelastine and the other with 0.1% fluorometholone alone. The Ocular Surface Disease Index (OSDI) and the signs of keratopathy, palpebral conjunctiva papillae and conjunctival congestion were scored before and at one, two and six weeks after treatment and compared between the groups. The intra-ocular pressure (IOP) was also monitored. There were no significant differences between the groups in the baseline mean scores of signs and OSDI scores, which gradually improved at all visits after therapy in both groups. Although the time effect was significant for all the parameters (all p < 0.001), the reduction in corneal involvement scores from week 2 to week 6 was insignificant in both groups (p = 0.460 for the steroids group and p = 0.074 for the combination group). All signs and symptoms were significantly more improved in the combination group than in the isolated group at each control visit. IOP remained stable at all visits (all p < 0.001), except one patient in each group had elevated IOP over 21 mmHg. While both the isolated use of fluorometholone and combined use of azelastine and fluorometholone are effective in alleviating the signs and symptoms of severe ACD, optimal response can be achieved with adjunctive treatment including azelastine.

Morphological and Functional Changes of Meibomian Glands in Pediatric and Adult Patients with Allergic Conjunctivitis

Allergic conjunctivitis (AC) is one of the most common ocular disorders in clinical practice and is associated with meibomian gland dysfunction. This study aimed to explore the morphological and functional changes of meibomian glands (MGs) in pediatric and adult patients with AC and to analyze their potential predictors. In our prospective, observational cohort study, a total of 59 patients with AC were enrolled, with 30 patients aged ≤16 years in the pediatric group and 29 patients in the adult group. All patients underwent examinations at baseline and last visit when the complete resolution of conjunctival papillae was identified. An automatic MG analyzer was used to measure the morphological and functional parameters of MGs, including their area ratio (GA), tortuosity index (TI), and signal index (SI). Two groups were comparable at baseline in terms of characteristics and MG parameters (p > 0.05). The morphological (length, square, and GA) and functional MG parameters (SI) of AC patients significantly improved in the pediatric group after treatment (all p < 0.05), but not in the adult group. The change in the GA correlated with age, sex, GA, TI, and SI at baseline (all p < 0.05). Age (p = 0.001) and GA (p < 0.001) at baseline were predictors of an improvement in the GA of MGs. The findings showed that the structure and function of MGs in pediatric patients with AC seem to improve after the conjunctival papillae disappear, but not in adult patients.

Corneal Scheimpflug topography values to distinguish between normal eyes, ocular allergy, and keratoconus in children

To identify and compare keratometric, corneal thickness, and elevation parameters and indices among healthy children, ocular allergy, and keratoconus using the OCULUS Pentacam Scheimpflug topography system. This study included healthy children, children with ocular allergy (OA) without keratoconus, and children with keratoconus (KC). The study design consisted of a prospective evaluation and review of medical records from a Brazilian ophthalmology department. The exclusion criteria were inability to undergo the ocular exam, other ocular diseases, contact lens wear, and topographic corneal ectasia. The effect of each corneal parameter was evaluated using univariate and multivariate logistic regression models adjusted for sex and age, and ROC curves were used to assess the ability each variable to discriminate among groups. A total of 182 subjects were included: healthy children (n = 99), children with OA (n = 32), and children with KC (n = 51). Groups differed in terms of sex, with more males in the OA group (73.2%) and the KC group (67.7%) than in the control group (40.9%). All corneal parameters studied differed significantly between the control and KC groups, and between the OA and KC groups; they also differed significantly between the three groups in terms of astigmatism, q-value, CCT, TP, BAD-D, and ARTmax values. We present the first study to describe and compare corneal tomographic parameters in healthy children, OA, and KC. Keratometry indices, ACD, ARTmax, AETP, and PETP were found to be the most useful for differentiating between healthy and KC children.IBR registry number: CAAE 54921916.9.0000.5404.

Formulation of olopatadine hydrochloride viscous eye drops - physicochemical, biopharmaceutical and efficacy assessment using in vitro and in vivo approaches

The aim of this work was the formulation and the comprehensive evaluation of the viscous eye drops using vehicles containing medium chain chitosan (0.5% w/v), hydroxypropyl guar gum (0.25% w/v) and their combination as carriers for olopatadine (0.1% w/v). Physicochemical properties (appearance, clarity, pH, osmolality, viscosity and drug content) of the tested formulations were within acceptable ranges for the ophthalmic preparations, while DSC and FT-IR techniques demonstrated the compatibility between olopatadine and polymers. The drug permeability was successfully estimated in vitro using both HCE-T cell-based models (Model I and Model II) and the parallel artificial membrane permeability assay (PAMPA), considering the impact of chitosan as a permeation enhancer. The MTT cytotoxicity assay demonstrates that the tested formulations (diluted 10-fold in HBSS pH 5.5) were non-toxic and well tolerated. An ocular itch test on mice was carried out with the formulation containing the combination of polymers comparable with a commercially available olopatadine eye drops without viscosity enhancers. The tested eye drops produced a slightly higher anti-pruritic/analgesic-like effect than the commercial preparation. It could be assumed that the use of this viscous ophthalmic vehicle due to its advanced mucoadhesive properties and good safety profile is a feasible strategy to improve the efficacy of olopatadine.

CLEAR - Contact lens technologies of the future

Contact lenses in the future will likely have functions other than correction of refractive error. Lenses designed to control the development of myopia are already commercially available. Contact lenses as drug delivery devices and powered through advancements in nanotechnology will open up further opportunities for unique uses of contact lenses. This review examines the use, or potential use, of contact lenses aside from their role to correct refractive error. Contact lenses can be used to detect systemic and ocular surface diseases, treat and manage various ocular conditions and as devices that can correct presbyopia, control the development of myopia or be used for augmented vision. There is also discussion of new developments in contact lens packaging and storage cases. The use of contact lenses as devices to detect systemic disease has mostly focussed on detecting changes to glucose levels in tears for monitoring diabetic control. Glucose can be detected using changes in colour, fluorescence or generation of electric signals by embedded sensors such as boronic acid, concanavalin A or glucose oxidase. Contact lenses that have gained regulatory approval can measure changes in intraocular pressure to monitor glaucoma by measuring small changes in corneal shape. Challenges include integrating sensors into contact lenses and detecting the signals generated. Various techniques are used to optimise uptake and release of the drugs to the ocular surface to treat diseases such as dry eye, glaucoma, infection and allergy. Contact lenses that either mechanically or electronically change their shape are being investigated for the management of presbyopia. Contact lenses that slow the development of myopia are based upon incorporating concentric rings of plus power, peripheral optical zone(s) with add power or non-monotonic variations in power. Various forms of these lenses have shown a reduction in myopia in clinical trials and are available in various markets.

Increased Expression of TLR4 in Circulating CD4+T Cells in Patients with Allergic Conjunctivitis and In Vitro Attenuation of Th2 Inflammatory Response by Alpha-MSH

Ocular allergic diseases are frequently seen in ophthalmological clinical practice. Immunological damage is mediated by a local Th2 inflammatory microenvironment, accompanied by changes in circulating cell subsets, with more effector cells and fewer T regulatory cells (Tregs). This study aimed to evaluate the involvement of toll-like receptor 4 (TLR4) and α-melanocyte stimulating hormone (α-MSH) in the immune regulation associated with perennial allergic conjunctivitis (PAC). We performed an Ag-specific stimulation during 72 h of culturing with or without lipopolysaccharide (LPS) or α-MSH in peripheral blood mononuclear cells (PBMC), analyzing the cell subsets and cytokines induced by the stimuli. We also determined α-MSH in tear samples from healthy donors (HD) or PAC patients. Our findings demonstrate an immunological dysregulation characterized by an increased frequency of CD4+TLR4+ in the PBMC of patients with PAC, compared to HD. Most of these CD4+TLR4+ cells were also CD25+, and when α-MSH was added to the culture, the percentage of CD4+CD25+FoxP3+ increased significantly, while the percentage of CD69+ cells and cytokines IL-4 and IL-6 were significantly decreased. In tears, we found an increased concentration of α-MSH in PAC patients, compared with HD. These findings indicate a novel mechanism involved in controlling ocular allergic diseases, in which α-MSH diminishes the concentration of IL-6 and IL-4, restoring the frequency of Tregs and down-regulating CD4 activation. Moreover, we demonstrated the involvement of CD4+TLR4+ cells as an effector cell subset in ocular allergy.

Itch in Organs Beyond the Skin

PURPOSE OF REVIEW

The purpose of this review was to explore mechanisms, causes, and therapies of itchy conditions involving organs beyond the skin including the eyes, ears, nose, and genital region.

RECENT FINDINGS

Conditions which cause itch in these locations vary from skin diseases that extend to these areas (i.e., atopic dermatitis, seborrheic dermatitis, and psoriasis) to allergic conditions (i.e., allergic rhinitis and conjunctivitis) and to neuropathic conditions that relate to afferent nerve fiber damage (i.e., lumbosacral radiculopathies in genital disease) as well as some psychological components. Similar to the skin, itch in these locations involves a complex interaction between epithelial cells, unmyelinated C nerve fibers, and cytokines. There is also a significant component of neural sensitization phenomena. Mechanisms of itch beyond the skin are currently an understudied topic that affects millions of patients. Future research should be done in order to further understand the pathophysiology of itch in these body sites.

Total Tear IgE Levels Correlate with Allergenic and Irritating Environmental Exposures in Individuals with Dry Eye

Dry eye (DE) and allergic conjunctivitis may present similarly, and it remains unclear whether some individuals have an underlying allergic component to their DE. To better understand this relationship, we performed a cross-sectional study in 75 individuals with DE symptoms and/or signs. Immunoglobulin E (IgE) levels in tear samples were quantified and home environmental exposures assessed via standardized survey. Tears were collected by Schirmer strip, and total tear IgE levels were quantified using enzyme-linked immunosorbent assay (ELISA). Data were analyzed using descriptive statistics and linear and logistic regressions. The main outcome measures were total tear IgE levels and their association with environmental exposures. The mean age of the subjects was 66.2 ± 7.8 years. Sixty-two individuals had dry eye symptoms (Dry Eye Questionnaire-5 ≥ 6), and 75 had one or more signs of DE. Detectable total tear IgE levels were observed in 76% of subjects, and 17.3% had high levels (>1 ng/mL). Individuals with exposure to pet(s) (odds ratio (OR) 11.5, p = 0.002) and smoke (OR 38.6, p = 0.008) at home were more likely to have high IgE levels compared to those not exposed. Individuals with tears collected during spring or summer were 3.9 times (p = 0.028) more likely to have high IgE compared to those sampled at other times of year. Subjects born in the US were 3.45 times (p = 0.010) more likely to have high IgE compared to individuals born outside the US. To conclude, a majority of individuals with DE symptoms and/or signs had detectable IgE levels in their tears. High tear IgE levels were correlated with allergy season and exposures in the home linked with allergy.

Management of Ocular Allergy Itch With an Antihistamine-Releasing Contact Lens

Supplemental Digital Content is Available in the Text.

Purpose:

A contact lens (CL)-based drug delivery system for therapeutic delivery of the antihistamine ketotifen was tested in 2 parallel, conjunctival allergen challenge-based trials.

Methods:

Both trials employed the same multicenter, randomized, placebo-controlled protocol. Test lenses were etafilcon A with 0.019 mg ketotifen; control lenses were etafilcon A with no added drug. Subjects were randomized into 3 treatment groups. Group 1 received test lens in one eye and control lens in the contralateral eye; the eye chosen to receive test lens was randomly selected in a 1:1 ratio. Group 2 received test lenses bilaterally, and group 3 received control lenses bilaterally. Allergen challenges were conducted on 2 separate visits: following lens insertion, the subjects were challenged at 15 minutes (to test onset) and 12 hours (to test duration). The primary endpoint was ocular itching measured using a 0 to 4 scale with half-unit steps. Secondary endpoints included ciliary, conjunctival, and episcleral hyperemia.

Results:

The mean itching scores were lower for eyes wearing the test lens as compared to those that received control lenses, indicating that the test lens effectively reduced allergic responses. Mean differences in itching were statistically and clinically significant (mean score difference ≥ 1) at both onset and duration for both trials.

Conclusions:

This large-scale assessment (n = 244) is the first demonstration of efficacy for CL delivery of a therapeutic for ocular allergy. Results are comparable to direct topical drug delivery and suggest that the lens/ketotifen combination can provide a means of simultaneous vision correction and treatment for CL wearers with ocular allergies.

Diagnosing and managing allergic conjunctivitis in childhood: The allergist's perspective

Allergic conjunctivitis in childhood often poses problems of diagnosis and management for the allergist. We present the salient points concerning the diagnosis and treatment of ocular allergy emerging from a large cohort survey conducted jointly in the departments of ophthalmology and paediatric allergy in a French teaching hospital. Seasonal acute conjunctivitis is a common disorder and not overly difficult to diagnose and treat when associated with rhinitis leading to allergic rhinoconjunctivitis. An ophthalmologist should be consulted when conjunctivitis occurs alone and if another form of conjunctivitis is suspected, such as perennial allergic conjunctivitis, vernal keratoconjunctivitis or atopic keratoconjunctivitis. When IgE-mediated hypersensitivity assessment does not establish aetiological diagnosis, a conjunctival allergen provocation test can be performed. The principal non-IgE-mediated allergy is chronic blepharoconjunctivitis. The main problem for differential diagnosis is the presence of signs suggestive of dry eye. Management includes non-pharmacological treatments, such as lacrimal substitutes, avoidance measures and protection of the ocular surface. Second-line treatment consists of eye drops, preferably single dose or without additives and with dual local action, mast cell stabilizer action and antihistaminic action. Third-line treatment is reserved for severe forms. Short-lasting local steroid therapy can control flare-ups of allergic keratoconjunctivitis, which should have specialized follow-up. Cyclosporine is a disease-modifying treatment, which is both effective and well tolerated.

Allergy screening in a schoolchildren-based population

BACKGROUND

Schoolchildren screening for allergic diseases may improve early identification and management of atopic children. The aim of this study was to perform a schoolchildren screening program for identification of children with allergic diseases.

METHODS

All parents of children attending to 13 primary schools in the city of Rome were requested to fill in a demographic data form and the ChAt questionnaire. Allergological evaluation was performed in the children with suspect of allergy (ChAt score > 2). Ocular examination was performed to identify signs of allergic conjunctivitis. The presence of allergic symptoms was related to demographic and environmental variables.

RESULTS

A total of 2667 children (mean age: 7.1 ± 1 years) were included, and 2489 (93.3%) parents completed the ChAt questionnaire. Results of ChAt questionnaire showed a previous diagnosis of allergic disease in 637 (25.6%) children and the potential presence of an allergic disease (ChAt score > 2) in 35.1%. Multivariate analysis showed that older age, male gender, and having less than two siblings were associated with higher risk of allergic disease. Visual screening showed the presence of clinical signs of allergic conjunctivitis in 2% of children. Allergologic evaluation in 334 children confirmed the diagnosis of allergic disease in 324 (97%) cases. Among them, 97 (29.9%) did not refer to a previous formal diagnosis of allergic condition.

CONCLUSIONS

This study confirmed that schoolchildren screening using ChAt questionnaire could represent a useful tool for early identification of yet undiagnosed atopic children.

Translational Preclinical Pharmacologic Disease Models for Ophthalmic Drug Development

Preclinical models of human diseases are critical to our understanding of disease etiology, pathology, and progression and enable the development of effective treatments. An ideal model of human disease should capture anatomical features and pathophysiological mechanisms, mimic the progression pattern, and should be amenable to evaluating translational endpoints and treatment approaches. Preclinical animal models have been developed for a variety of human ophthalmological diseases to mirror disease mechanisms, location of the affected region in the eye and severity. These models offer clues to aid in our fundamental understanding of disease pathogenesis and enable progression of new therapies to clinical development by providing an opportunity to gain proof of concept (POC). Here, we review preclinical animal models associated with development of new therapies for diseases of the ocular surface, glaucoma, presbyopia, and retinal diseases, including diabetic retinopathy and age-related macular degeneration (AMD). We have focused on summarizing the models critical to new drug development and described the translational features of the models that contributed to our understanding of disease pathogenesis and establishment of preclinical POC.

In vitro and in vivo performance of epinastine hydrochloride-releasing contact lenses

A number of drug-releasing contact lenses are currently being studied to address issues inherent in eye drops as a drug delivery method. In this study, we developed epinastine hydrochloride-releasing daily soft contact lenses for treatment of allergic conjunctivitis and examined their in vitro and in vivo performance. Preformed soft contact lenses with/without ionic functional groups were soaked in a solution of epinastine hydrochloride in phosphate-buffered saline to prepare epinastine hydrochloride-releasing soft contact lenses. Among these contact lenses with different ionicities, anionic lenses demonstrated the maximum, relatively linear epinastine hydrochloride release, in vitro. The amount of epinastine hydrochloride release was directly proportional to the concentration of the epinastine hydrochloride solution used to prepare the contact lens. The epinastine hydrochloride-releasing anionic soft contact lens also demonstrated prolonged drug release and significantly greater efficacy compared with epinastine hydrochloride eye drops 12 h after treatment, in vivo. Further studies are required to determine the appropriate amount of epinastine hydrochloride to be contained in the anionic soft contact lenses.

Resolvin D1 treatment on goblet cell mucin and immune responses in the chronic allergic eye disease (AED) model

Severe, chronic eye allergy is an understudied, vision-threatening condition. Treatments remain limited. We used a mouse model of severe allergic eye disease (AED) to determine whether topical application of the pro-resolution mediator Resolvin D1 (RvD1) terminates the response. AED was induced by injection of ovalbumin (OVA) followed by topical challenge of OVA daily. RvD1 was applied topically prior to OVA. Clinical symptoms were scored. Eye washes were assayed for MUC5AC. After 7 days, eyes were removed and the number of goblet cells, T helper cell responses and presence of immune cells in draining lymph nodes and conjunctiva determined. Topical RvD1 treatment significantly reduced symptoms of AED. RvD1 did not alter the systemic type 2 immune response in the lymph nodes. AED increased the total amount of goblet cell mucin secretion, but not the number of goblet cells. RvD1 prevented this increase, but did not alter goblet cell number. Absolute numbers of CD4 + T cells, total CD11b + myeloid cells, eosinophils, neutrophils, and monocytes, but not macrophages increased in AED versus RvD1-treated mice. We conclude that topical application of RvD1 reduced the ocular allergic response by local actions in conjunctival immune response and a decrease in goblet cell mucin secretion.

Phase III trials examining the efficacy of cetirizine ophthalmic solution 0.24% compared to vehicle for the treatment of allergic conjunctivitis in the conjunctival allergen challenge model

Purpose

The purpose of these Phase III studies was to evaluate the efficacy and safety of cetirizine ophthalmic solution 0.24% compared with vehicle in the treatment of allergen-induced conjunctivitis using the Ora conjunctival allergen challenge (CAC)^® model.

Methods

The single-center (Study 1) and multi-center (Study 2), double-masked, randomized, vehicle-controlled, parallel group, CAC studies were conducted over ~5 weeks and four study visits. The study design only differed in entry criteria: Study 2 required more severe allergic conjunctivitis symptoms. Subjects were screened for an allergen response at Visits 1 and 2 and then randomized at Visit 3. Approximately 100 subjects were randomized in each study. The primary efficacy endpoints were ocular itching and conjunctival redness 15 minutes and 8 hours post-treatment, post-CAC.

Results

Cetirizine treatment administered 15 minutes or 8 hours prior to CAC resulted in significantly lower ocular itching at all time points post-CAC (P<0.0001) compared to vehicle in both studies. Conjunctival redness measured by the investigator was significantly lower after cetirizine treatment compared to vehicle at 7 minutes post-CAC at both 15 minutes and 8 hours post-treatment in both studies (P<0.05). All secondary endpoints were in favor and confirmatory of cetirizine efficacy with significant improvement in chemosis, eyelid swelling, tearing, ciliary redness, and episcleral redness, as well as nasal symptoms (rhinorrhea, nasal pruritus, ear or palatal pruritus, and nasal congestion) post-CAC. The most robust treatment differences were observed in Study 2 where more severe symptoms were required for study entry (P<0.05). No safety concerns for cetirizine ophthalmic solution 0.24% were identified.

Conclusion

Cetirizine ophthalmic solution 0.24% was shown to be efficacious in the treatment of ocular and nasal signs and symptoms associated with allergic conjunctivitis and demonstrated a favorable safety profile. Clinical efficacy was demonstrated with a 15-minute onset of action and añ8-hour duration of action.

Signaling pathways activated by resolvin E1 to stimulate mucin secretion and increase intracellular Ca2+ in cultured rat conjunctival goblet cells

Glycoconjugate mucin secretion from conjunctival goblet cells is tightly regulated by nerves and specialized pro-resolving mediators (SPMs) to maintain ocular surface health. Here we investigated the actions of the SPM resolvin E1 (RvE1) on cultured rat conjunctival goblet cell glycoconjugate secretion and intracellular [Ca2+] ([Ca2+]i) and the signaling pathways used by RvE1. Goblet cells were cultured from rat conjunctiva in RPMI medium. The amount of RvE1-stimulated glycoconjugate mucin secretion was determined using an enzyme-linked lectin assay with Ulex Europaeus Agglutinin 1 lectin. Cultured goblet cells were also incubated with the Ca2+ indicator dye fura 2/AM and [Ca2+]i was measured. Cultured goblet cells were incubated with inhibitors to phospholipase (PL-) C, D, and A2 signaling pathways. RvE1 stimulated glycoconjugate secretion in a concentration dependent manner and was inhibited with the Ca2+ chelator BAPTA. The Ca2+i response was also increased in a concentration manner when stimulated by RvE1. Inhibition of PLC, PLD, and PLA2, but not Ca2+/calmodulin-dependent kinase blocked RvE1-stimulated increase in [Ca2+]i and glycoconjugate secretion. We conclude that under normal, physiological conditions RvE1 stimulates multiple pathways to increase glycoconjugate secretion and [Ca2+]i. RvE1 could be an important regulator of goblet cell glycoconjugate mucin secretion to maintain ocular surface health.

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.

The Prevalence of Ocular Allergy and Comorbidities in Chinese School Children in Shanghai

Objective

To investigate the prevalence and features of ocular allergy (OA) and comorbidities among school children in Shanghai, China.

Methods

This was a population-based cross-sectional study. Each participant completed an ISAAC-based questionnaire. The prevalence of OA symptoms, allergic rhinitis (AR) asthma, atopic dermatitis (AD), and sensitization to mites, pollen, and food was analyzed.

Results

A total of 724 and 942 completed questionnaires from the 7–9-year-old (young group) and the 12–14-year-old (teen group) groups were analyzed, respectively. The overall prevalence of OA symptoms was 28%. However, more young students (10.6%) reported mild to severe daily life interference caused by OA than the teens (5.7%). The young group had higher prevalence of diagnosed allergic conjunctivitis (10.2%). The overall prevalence of AR symptom, diagnosed asthma, and diagnosed AD was 40.4%, 11.6%, and 16.7%, respectively. Young children had higher prevalence of diagnosed AR and AD than the teens. There were gender associated differences in the prevalence of AR and asthma among young children, but not among the teens. The comorbidities associated with OA was also analyzed. Sensitization to mites, food, and pollen was associated with higher prevalence of allergic conditions.

Conclusions

OA together with other allergic conditions affected a significant number of children in Shanghai.

Collision-induced dissociation pathways of H1-antihistamines by electrospray ionization quadrupole time-of-flight mass spectrometry

Over the past decades, mass spectrometry technologies have been developed to obtain mass accuracies of one ppm or less. Of the newly developed technologies, quadrupole time-of-flight mass spectrometry (Q-TOF-MS) has emerged as being well suited to routine and high-throughput analyses of pharmaceuticals. Dietary supplements and functional foods have frequently been found to be contaminated with pharmaceuticals. In our continuous efforts to develop methodologies to protect public health against adulterated dietary supplements, we have constructed a mass spectral database for 21 H₁-antihistamines encountered as adulterants by using liquid chromatography-electrospray ionization (LC-ESI)/Q-TOF-MS, and have proposed their possible collision-induced dissociation pathways. This database will be very useful for the rapid and accurate detection of H₁-antihistamines (known) and their analogues (unknown) illegally added to dietary supplements as well as in other sample matrices.

Pharmacokinetics and safety of olopatadine hydrochloride 0.77% in healthy subjects with asymptomatic eyes: data from 2 independent clinical studies

Purpose

To assess the pharmacokinetics and safety of hydrochloride ophthalmic solution 0.77% olopatadine from 2 independent (Phase I and Phase III, respectively) clinical studies in healthy subjects.

Materials and methods

The Phase I, multicenter, randomized (2:1), vehicle-controlled study was conducted in subjects ≥18 years old (N=36) to assess the systemic pharmacokinetics of olopatadine 0.77% following single- and multiple-dose exposures. The Phase III, multicenter, randomized (2:1), vehicle-controlled study was conducted in subjects ≥2 years old (N=499) to evaluate long-term ocular safety of olopatadine 0.77%. Subjects received olopatadine 0.77% or vehicle once daily bilaterally for 7 days in the pharmacokinetic study and 6 weeks in the safety study.

Results

In the pharmacokinetic study, olopatadine 0.77% was absorbed slowly and reached a peak plasma concentration (C_max) of 1.65 ng/mL following single-dose and 1.45 ng/mL following multiple-dose exposures in 2 hours (time to reach maximum plasma concentration [T_max]). After reaching peak concentrations, olopatadine showed a similar mono-exponential decay following single and multiple doses with mean elimination half-life ranging from 2.90 to 3.40 hours. No accumulation in olopatadine exposure (C_max and area under the plasma concentration–time curve from 0 to 12 hours) was evident after multiple doses when compared to single dose. In the safety study, treatment-emergent adverse events were reported in 26.7% and 31.4% of subjects with olopatadine 0.77% and vehicle, respectively. Blurred vision was the most frequent ocular treatment-emergent adverse event in both treatment groups (olopatadine 0.77% vs vehicle, 4.8% vs 4.1%). No deaths or serious adverse events were reported during the study.

Conclusion

Olopatadine 0.77% had minimal systemic exposure or accumulation in healthy subjects and was well tolerated in both adult and pediatric subjects.

Mucosal immune tolerance at the ocular surface in health and disease

The ocular surface is constantly exposed to environmental irritants, allergens and pathogens, against which it can mount a prompt immune response to preserve its integrity. But to avoid unnecessary inflammation, the ocular surface's mucosal immune system must also discriminate between harmless and potentially dangerous antigens, a seemingly complicated task. Despite its unique features, the ocular surface is a mucosal lining, and as such, it shares some homeostatic and pathophysiological mechanisms with other mucosal surfaces. The purpose of this review is to explore the mucosal homeostatic immune function of the ocular surface in both the healthy and diseased states, with a special focus on mucosal immunology concepts. The information discussed in this review has been retrieved by PubMed searches for literature published from January 1981 to October 2016.

Lipoxin A4 Counter-regulates Histamine-stimulated Glycoconjugate Secretion in Conjunctival Goblet Cells

Conjunctival goblet cells synthesize and secrete mucins which play an important role in protecting the ocular surface. Pro-resolution mediators, such as lipoxin A₄ (LXA₄), are produced during inflammation returning the tissue to homeostasis and are also produced in non-inflamed tissues. The purpose of this study was to determine the actions of LXA₄ on cultured human conjunctival goblet cell mucin secretion and increase in intracellular [Ca²⁺] ([Ca²⁺]_i) and on histamine-stimulated responses. LXA₄ increased mucin secretion and [Ca²⁺]_i, and activated ERK1/2 in human goblet cells. Addition of LXA₄ before resolvin D1 (RvD1) decreased RvD1 responses though RvD1 did not block LXA₄ responses. LXA₄ inhibited histamine-stimulated increases in mucin secretion, [Ca²⁺]_i, and ERK1/2 activation through activation of β-adrenergic receptor kinase 1. We conclude that conjunctival goblet cells respond to LXA₄ through the ALX/FPR2 receptor to maintain homeostasis of the ocular surface and regulate histamine responses and could provide a new therapeutic approach for allergic conjunctivitis and dry eye diseases.

Evidence of seasonality and effects of psychrometry in dry eye disease

PURPOSE

Current models consider the development of dry eye disease (DED) as a more or less continuous process with only minor daily variations. Clinical evidence, however, does suggest the existence of phase-like recurring dry eye complaints that may be linked to seasonal environmental conditions. In this survey-based study, we examined the influence of seasonality in dry eye pathophysiology.

METHODS

A specific protocol for a telephone interview was created. Then, 738 patients suffering from dry eye and/or Sjögren's syndrome were interviewed and asked about the impact of the four seasons and other weather conditions on their ocular symptoms. Data were statistically analysed. All data were compared in respect to the relation between season, gender, country of origin and the presence of comorbidities.

RESULTS

Overall, 47% of respondents stated that seasonal conditions had a high impact on their DED symptoms, with only 15% reporting that there was no seasonal impact on their symptoms. Wind was the most commonly reported weather condition to impact dry eye symptoms (for 71% of patients), followed by sunshine (60%) and heat (42%). Cold weather was also reported to aggravate dry eye sensation by 34% of patients. The two seasons most commonly associated with dry eye complaints were summer and winter (for 51% and 43% of patients, respectively). Only 8% stated that no weather conditions affected their symptoms.

DISCUSSION

This study confirms the seasonal enhancement of dry eye sensations and symptoms. Environmental characteristics such as cold and heat as well as wind were the most commonly cited triggering factors. Geographical differences do exist between the countries surveyed and the seasonal peak of complaints appears related to temperature and humidity. The main seasons of dry eye complaints in Europe were winter and summer. Such seasonal characteristics in ocular surface disease should be kept in mind when considering diagnosis and treatment as well when investigating the ocular surface.

CONCLUSION

Our study confirmed high prevalence of both seasonal and weather-related enhancement of dry eye sensations and symptoms.

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.

Treating allergic conjunctivitis: A once-daily medication that provides 24-hour symptom relief

BACKGROUND

Allergic conjunctivitis (AC) is a common ocular inflammatory manifestation of allergen exposure in sensitized individuals. Signs and symptoms of AC can decrease quality of life, interfere with productivity, and lead to considerable economic burden. Consistent suppression of conjunctival inflammation is necessary for managing AC, but currently available medications require frequent administration and exhibit limited duration of action.

METHODS

In this review, we summarized AC pathogenesis, diagnosis, and current treatment options as well as their limitations. Findings from the literature were discussed in the context of the unmet need for a once-daily medication with sustained 24-hour effectiveness.

RESULTS

Topical pharmacologic treatments are the most common approach for managing extant AC; however, most available medications require multiple daily instillations. Dual-acting antihistamine-mast cell stabilizing agents are currently considered first-line therapeutics for AC because they provide acute relief of signs and symptoms and block persistent inflammation to promote regression of AC. Recent studies of a newly-developed, higher-concentration formulation of a dual-acting antihistamine-mast cell stabilizer have demonstrated that this formulation provides a 24-hour duration of action with once-daily dosing.

CONCLUSIONS

Dual-acting AC medications exhibit a high degree of overall effectiveness and are well tolerated for chronic use. A newly available once-daily medication that manages signs and symptoms of AC for a full 24 hours may be considered a treatment of choice for patients experiencing seasonal or perennial AC. ClinicalTrials.gov NCT01743027 and NCT01479374.

Prevalence of allergic conjunctivitis among basic school children in the Kumasi Metropolis (Ghana): a community-based cross-sectional study

BACKGROUND

There seems a preponderance of hospital-based studies on the prevalence of Allergic Conjunctivitis (AC) compared to community-based ones, particularly among children in Ghana and Africa as a whole. Meanwhile, literature supports the possibility of underdiagnosing AC in the hospital setting; exponentially so when males generally have poor hospital-attending behavior. This may lead to underestimation of the true burden of AC. Consequently, the purpose of the current community-based study was to determine the prevalence of AC among basic school children in the Kumasi Metropolis, while identifying its associated symptoms.

METHODS

A cross-sectional community-based study involving 1571 students from 11 basic schools (Primary and JHS) participated in the study. Data collection started in November 2011 and was completed in March 2014. After history taking, subjects underwent a battery of tests; visual acuity, objective refraction, anterior and posterior segments examination with a slit-lamp and a direct ophthalmoscope respectively.

RESULTS

The prevalence of AC was 39.9 %. The mean (± SD) age of participants was 8 ± 0.65 years. AC was significantly associated with gender (p < 0.05), but not with age (p > 0.05). A total of 70 % of the students with AC never had any form of treatment.

CONCLUSIONS

AC is an endemic ocular disease among basic schools in the Kumasi metropolis and therefore calls for pragmatic and proactive measures to reduce its burden and effects on its victims. Public health measures may be required to help reduce the burden associated with this condition.

Advances in pharmacotherapy for allergic conjunctivitis

INTRODUCTION

Allergy is the fifth leading group of chronic diseases, affecting as much as 40% of the first-world population. Its pathophysiology has a genetic component, and is driven by the immune system's sensitized response to antigens and environmental factors. As research continues to uncover the mediators responsible for ocular allergy, the development of novel drugs should progress.

AREAS COVERED

A literature review of allergic conjunctivitis, ocular allergy and their treatment was performed using PubMed and Medline. Additional information is also included from clinicaltrials.gov and associated web sites for drugs currently in clinical trials.

EXPERT OPINION

The initial step of therapy remains identification and avoidance of allergic triggers. The mainstay of treatment is the new generation of dual-acting antihistamines. Drugs that improve the magnitude and duration of relief, with greater subject responder rates, are gradually making their way into the clinic. Allergic conjunctivitis is a relatively easy disease to study because of the availability of models such as the conjunctival allergen challenge. New classes of drugs that target inflammatory pathways or mediators involved in the early and late-phase allergic response are being screened in these models and we are making progress in identifying the next generation of anti-allergic therapy.

Effect of alcaftadine 0.25% on ocular itch associated with seasonal or perennial allergic conjunctivitis: a pooled analysis of two multicenter randomized clinical trials

PURPOSE

Seasonal and perennial allergic conjunctivitis represent the majority of cases of ocular allergy. This analysis was designed to evaluate the efficacy and safety of once-daily alcaftadine 0.25% in preventing ocular itching associated with seasonal or perennial allergic conjunctivitis.

SUBJECTS AND METHODS

Pooled data from two double-masked, multicenter, placebo-controlled studies using the conjunctival allergen challenge (CAC) model of allergic conjunctivitis were analyzed. Subjects randomized to receive treatment with alcaftadine 0.25% or placebo were challenged with seasonal (grass, ragweed, trees) or perennial (cat dander, cat hair, dog dander, dust mites, cockroach) allergens, 16 hours after treatment instillation. The primary efficacy measure was subject-evaluated mean ocular itching at 3 minutes post-CAC. Secondary measures included ocular itching at 5 and 7 minutes post-CAC. The proportion of subjects with minimal itch (itch score <1) and zero itch (itch score =0), and safety were also assessed.

RESULTS

A total of 189 subjects enrolled in the two studies were treated with alcaftadine or placebo. Overall, 129 subjects were challenged with seasonal allergens and 60 subjects were challenged with perennial allergens. Alcaftadine 0.25% achieved a statistically significant reduction in mean itch score at 3, 5, and 7 minutes post-CAC compared with placebo in subjects challenged with seasonal allergens (P<0.0001 at all time points) and those challenged with perennial allergens (P<0.0001 at all time points). A higher percentage of subjects treated with alcaftadine compared with placebo achieved minimal itch (P≤0.001 versus placebo at all time points) and zero itch (P<0.05 at all time points except 7 minutes for perennial) when challenged with either seasonal or perennial allergens. No treatment-related or serious adverse events were reported.

CONCLUSION

Once-daily alcaftadine 0.25% ophthalmic solution was well tolerated and demonstrated effective relief of ocular itching in subjects challenged with allergens classic for triggering either seasonal or perennial allergic conjunctivitis.