Antihistamines in Ocular Allergy: Are They All Created Equal?

Evidence-based use of antihistamines for treatment of allergic conditions

Available since the 1940s, H1 antihistamines are mainstay treatments for allergic conditions such as allergic rhinitis and urticaria. They function as inverse agonists that bind to the H1 receptor to inhibit histamine-induced inflammation. The older, first-generation drugs are no longer recommended for patient use because of their well-documented negative adverse effect profile. Evidence has been accumulating to support a newer generation of H1 antihistamines in oral and intranasal formulations, including in combination with intranasal corticosteroids. The literature is replete with large meta-analyses and systematic reviews establishing the safety and efficacy of second-generation H1 antihistamines in adult and pediatric allergic rhinitis populations, including combination nasal spray agents (eg, MP29-02 or MP-AzeFlu). Although intraclass differences do exist, patient preference, access, and costs should be the priority. Robust data on the regular, not as needed use of H1 antihistamines for urticaria have been published, including in the management of children and pregnant or lactating women. In addition, H1 antihistamines can be used in other related allergic conditions, such as the secondary symptoms of anaphylaxis, to provide patients with greater comfort, including in allergic asthma, depending on the individual.

Use of Ketotifen Fumarate-Eluting Daily Disposable Soft Contact Lens in Management of Ocular Allergy: Literature Review and Report of Two Cases

We present two cases in which the drug-eluting daily disposable soft contact lens (DDSCL) Acuvue® Theravision^TM with Ketotifen (Johnson & Johnson Vision Care, Inc., Jacksonville, Florida, USA) (ATK), which contains the anti-allergic drug ketotifen fumarate, alleviated ocular allergic symptoms. Case 1 was a 57-year-old woman with a history of allergic conjunctivitis in the spring and fall. In the summer and winter, the patient used frequent replacement soft contact lenses, but in the allergy seasons, she used DDSCLs in combination with anti-allergic eye drops. She agreed to start wearing ATK lenses from before the next fall season. The lenses suppressed her allergic signs and symptoms, and she felt comfortable wearing them and continued their use throughout the season. Her symptoms were suppressed, providing her comforts that enabled uses of the CLs for some time. She successfully used the lenses again from the beginning of the next spring season. Case 2 was a 31-year-old woman with a history of cedar pollinosis. The patient previously used DDSCLs and was prescribed ATK lenses at her regular clinic. About one month later, she was referred to our department. With ATK lenses, she did not experience any subjective symptoms during the pollinosis season. At a subsequent visit, hyperemia had decreased compared with the initial visit. In these two cases, the use of ATK lenses from before until the end of both the spring and fall allergy seasons suppressed the symptoms of allergic conjunctivitis, allowing the patients to continue to wear contact lenses.

Ocular redness - II: Progress in development of therapeutics for the management of conjunctival hyperemia

Conjunctival hyperemia is one of the most common causes for visits to primary care physicians, optometrists, ophthalmologists, and emergency rooms. Despite its high incidence, the treatment options for patients with conjunctival hyperemia are restricted to over-the-counter drugs that provide symptomatic relief due to short duration of action, tachyphylaxis and rebound redness. As our understanding of the immunopathological pathways causing conjunctival hyperemia expands, newer therapeutic targets are being discovered. These insights have also contributed to the development of animal models for mimicking the pathogenic changes in microvasculature causing hyperemia. Furthermore, this progress has catalyzed the development of novel therapeutics that provide efficacious, long-term relief from conjunctival hyperemia with minimal adverse effects.

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.

The spectrum of allergic ocular diseases

OBJECTIVE

The purpose of this article is to review the pathophysiologic mechanisms, differential diagnosis, evaluation, and treatment of the various manifestations of ocular allergy, with an especial focus on immunoglobulin E (IgE)-mediated disease.

DATA SOURCES

A PubMed search was performed to include articles, using the search terms ocular allergy and allergic conjunctivitis.

STUDY SELECTIONS

Recent and relevant human studies in the English language pertaining to our topic of study were selected. Animal studies pertaining to pathophysiology of ocular allergy were also reviewed. We focused on clinical trials, practice guidelines, reviews, and systematic reviews. In addition, case reports were reviewed if they described rare clinical presentations, disease mechanisms, or novel therapies.

RESULTS

Ocular allergy encompasses both IgE- and non-IgE-mediated disease, and the clinical severity may range from mild to sight-threatening inflammation. A comprehensive treatment regimen including education, lifestyle measures, topical therapies, and even systemic interventions may be necessary for the effective management of ocular allergies, tailored according to symptom severity.

CONCLUSION

Ocular allergy is frequently encountered by allergists and eye-care specialists, and despite progressively increasing incidence, it often remains underdiagnosed and, hence, untreated.

Efficacy of Alcaftadine 0.25% (AGN-229666) for Once-daily Prevention of Cedar-Pollen Allergic Conjunctivitis: A Phase 3 Randomized Study

PURPOSE

This study evaluated the efficacy and safety of once-daily Alcaftadine 0.25% (AGN-229666) for prevention of signs and symptoms of Japanese cedar-pollen allergic conjunctivitis.

METHODS

This was a single-center, placebo-, and comparator-controlled study using the Ora-CAC® model of allergic conjunctivitis. The primary endpoint was ocular itching 16 hours after Alcaftadine 0.25% instillation; efficacy at 16 hours was compared with 0.1% Olopatadine, 4 hours after instillation. Secondary endpoints included conjunctival hyperemia.

RESULTS

263 Japanese subjects were enrolled; 224 completed the trial. Alcaftadine 0.25% was statistically superior to vehicle for relief of ocular itching at 16 hours (p < .0001). Alcaftadine 0.25% at 16 hours was non-inferior to Olopatadine at 4 hours. Alcaftadine 0.25% was significantly better than vehicle for relief of conjunctival hyperemia. All treatments showed a low frequency of ocular adverse events.

CONCLUSION

Once-daily Alcaftadine 0.25% is safe and effective in preventing signs and symptoms of Japanese cedar-pollen allergic conjunctivitis.

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.

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.

Treatment of allergic conjunctivitis with bepotastine besilate ophthalmic solution 1.5%

PURPOSE

To examine the pooled per-protocol ocular end points from two conjunctival allergen challenge (CAC) clinical trials of the dual-action antihistamine bepotastine besilate ophthalmic solution (BBOS) 1.5%.

METHODS

Two Phase III, placebo-controlled, double-masked, randomized clinical trials were conducted at a total of six separate centers using the CAC model of allergic conjunctivitis. The same study design was employed for both clinical trials, with subjects randomly assigned to either BBOS 1.5% (n=78) or placebo (n=79) treatment. Each subject received one eye drop of the test agent bilaterally at different study visits 15 minutes, 8 hours, or 16 hours prior to a CAC. Primary ocular end points included changes in ocular itching reported at 3, 5, and 7 minutes and conjunctival hyperemia assessed at 7, 15, and 20 minutes following each CAC. Secondary ocular end points included chemosis as well as episcleral and ciliary hyperemia judged by investigators, and tearing (scored as either absent or present) and eyelid swelling judged by subjects.

RESULTS

A statistically significant reduction in ocular itching was observed for BBOS 1.5% treatment compared to placebo at all time points (P<0.0001), while measures for onset and 8-hour persistence of action also reached clinical significance (ie, ≥1.0 unit difference) at a majority of time points. In addition, a significant reduction in conjunctival hyperemia was achieved at a majority of time points during the onset of action CAC test. Secondary end points were also significantly improved compared to placebo, most prominently for reduced tearing at all study visits and reduced eyelid swelling at the onset of action and 8-hour study visits. Adverse events were generally mild and transient.

CONCLUSION

BBOS 1.5% rapidly reduced CAC-induced ocular itching with duration of effectiveness of at least 8 hours after dosing. Certain secondary signs of inflammation were also significantly reduced.

A multicenter evaluation of the efficacy and duration of action of alcaftadine 0.25% and olopatadine 0.2% in the conjunctival allergen challenge model

Background

The purpose of this study was to evaluate the efficacy and duration of action of once-daily dosing with alcaftadine 0.25% ophthalmic solution and olopatadine 0.2% ophthalmic solution as compared with placebo in the prevention of ocular itching, and to directly compare the efficacy of alcaftadine 0.25% with olopatadine 0.2% in the prevention of ocular itching associated with allergic conjunctivitis using the conjunctival allergen challenge model.

Methods

Subjects with allergic conjunctivitis (n = 127) were enrolled in a multicenter, double-masked, randomized, active-controlled and placebo-controlled clinical trial. Using the conjunctival allergen challenge model, this study was conducted over the course of approximately 5 weeks. Subjects were randomized into one of three treatment arms: alcaftadine 0.25% ophthalmic solution, olopatadine 0.2% ophthalmic solution, or placebo. Study medications were administered twice over the course of the trial. The primary efficacy measure for the study was ocular itching evaluated by the subject at 3, 5, and 7 minutes post challenge. Secondary endpoints, measured at 7, 15, and 20 minutes post challenge, included conjunctival, ciliary, and episcleral redness, lid swelling, chemosis, and tearing. Duration of action was measured at 16 and 24 hours post-instillation of the study medication at visits 3 and 4, respectively.

Results

For the primary measure of ocular itching, both actives, alcaftadine 0.25% and olopatadine 0.2%, were statistically superior to placebo at all three measured time points for both the 16-hour and 24-hour measures (P < 0.0001). Eyes treated with alcaftadine 0.25% had numerically lower mean ocular itching scores than eyes treated with olopatadine 0.2% at every time point, and this difference was statistically significant at the 3-minute time point 16 hours post instillation (P = 0.026). Eyes treated with alcaftadine 0.25% and with olopatadine 0.2% displayed significantly less lid swelling relative to placebo at every time point for the 16-hour and 24-hour post-instillation visits (P < 0.005). Alcaftadine 0.25% was the only active treatment that provided statistically significant relief of chemosis at every time point of the 24-hour post-instillation visit.

Conclusion

Both the alcaftadine 0.25% and olopatadine 0.2% ophthalmic solutions provided highly effective relief of ocular itching at both 16 and 24 hours post-instillation. Treatment differences between the actives were most pronounced at the earliest time point (3 minutes post-challenge) following conjunctival allergen challenge (16 hours), when alcaftadine 0.25% ophthalmic solution was statistically superior to olopatadine 0.2% ophthalmic solution. Alcaftadine 0.25% was the only treatment to provide significant relief from chemosis at both 16 and 24 hours post-instillation. Both active treatments and placebo were generally safe and well tolerated.

Diagnostics and new developments in the treatment of ocular allergies

About 30% of people suffer from allergic symptoms, and 40% to 80% of them have eye symptoms. Atopic conjunctivitis is divided into seasonal allergic conjunctivitis and perennial allergic conjunctivitis. The treatment of seasonal allergic conjunctivitis is simple: antihistamines, anti-inflammatory agents, or cromoglycate. Perennial allergic conjunctivitis needs longer therapy with mast cell stabilizers and sometimes local steroids. Atopic keratoconjunctivitis requires long-term treatment of the lid eczema and keratoconjunctivitis. Vernal keratoconjunctivitis mainly affects children and young people. It commonly calms down after puberty. It demands intensive therapy, often for many years, to avoid serious complicating corneal ulcers. Giant papillary conjunctivitis is a foreign body reaction in contact lens users or patients with sutures following ocular surgery. Nonallergic eosinophilic conjunctivitis affects mostly middle-aged and older women with eosinophilic conjunctivitis and dry eye. Contact allergic blepharoconjunctivitis is often caused by cosmetics and eye medication. Work-related ocular allergies should be considered as a cause of resistant ocular symptoms in workplaces.

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

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

Alcaftadine for the Prevention of Itching Associated with Allergic Conjunctivitis

OBJECTIVE:

To evaluate the safety and efficacy of alcaftadine for the prevention of itching associated with allergic conjunctivitis.

DATA SOURCES:

A medical literature search was conducted in MEDLINE/PubMed (2006-February 2012) and EMBASE (2006-February 2012) using the search terms alcaftadine and Lastacaft. References from these publications were reviewed for additional resources. Additional information was collected from Web sites of the US government ( http://www.clinicaltrials.gov , http://www.fda.gov ) and of Allergan Inc., the manufacturer of Lastacaft ( http://www.lastacaft.com ).

STUDY SELECTION AND DATA EXTRACTION:

All identified articles and publications in English were reviewed for pharmacology, pharmacokinetics, efficacy, and safety data. Priority was placed on clinical trials.

DATA SYNTHESIS:

Two published clinical trials evaluated the efficacy of alcaftadine in the prevention of ocular itching and conjunctival redness associated with allergic conjunctivitis. One trial compared alcaftadine to placebo, and another trial compared alcaftadine to placebo and olopatadine HCl to placebo. Both studies showed superior efficacy, both clinically and statistically, in the prevention of ocular itching associated with allergic conjunctivitis compared to placebo. Although conjunctival redness was evaluated in the 2 trials, neither trial demonstrated both clinical and statistical significance. Both trials demonstrated a rapid onset of action of less than 15 minutes, as well as a duration of action greater than 16 hours, which supports the use of once-daily administration. Overall, alcaftadine was well tolerated, and common adverse effects, reported in less than 4% of patients, included ocular irritation, pruritus, erythema, and stinging or burning upon instillation. Ocular adverse effects were typically mild in severity and self-limiting.

CONCLUSIONS:

Alcaftadine is a safe and effective option for the prevention of ocular itching associated with allergic conjunctivitis, is dosed once daily, and is competitively priced among prescription medications for allergic conjunctivitis. Additional studies are needed to further evaluate the comparative efficacy among ocular antihistamine/mast cell stabilizing medications.

Involvement of leukotriene B4 in itching in a mouse model of ocular allergy

Itching of ocular allergy is alleviated but not completely relieved by H(1) histamine receptor antagonists, suggesting that histamine is not the sole itch mediator in ocular allergy. We investigated whether leukotriene B(4) (LTB(4)), a mediator of cutaneous itch, is involved in the itch of ocular allergy in mice. Mice were immunized by the repeated subcutaneous injections of ragweed pollen and alum into the caudal back, and given a subconjunctival injection of ragweed pollen extract into the palpebra for allergic challenge. Challenge with ragweed pollen extract markedly elicited ocular scratching in sensitized mice. The scratching was almost abolished by mast cell deficiency. The H(1) antagonist terfenadine partially inhibited scratching at a dose that almost completely suppressed plasma extravasation. Scratching was inhibited by the glucocorticoid betamethasone and the 5-lipoxygenase inhibitor zileuton at doses that inhibited the challenge-induced production of LTB(4). A subconjunctival injection of LTB(4) at doses 1/10,000 or less than that required for histamine elicited ocular scratching in naïve mice. The LTB(4) receptor antagonist ONO-4057 inhibited the ragweed pollen challenge-induced ocular scratching at doses that suppressed LTB(4)-induced ocular scratching. In addition to histamine, LTB(4) is involved in the ocular itching of pollen allergy. H(1) receptor antagonists with an inhibitory effect on the action and/or production of LTB(4) may have more potent anti-pruritic activity than selective H(1) antagonists.