|For mild symptoms, suggest combining an OTC
topical ketotifen fumarate 0.035% ophthalmic solution,
such as Alaway from Bausch + Lomb, in addition to
an OTC oral antihistamine.
There is hope for your patients with serious ocular allergies, and it’s found in the following medications.
As an eyecare practitioner, you probably deal with patient complaints of itchy, watery and red eyes on a routine basis. Allergic conjunctivitis (AC) is a common allergic disorder that affects 6% to 30% of the general population conservatively.
The prevalence of ocular allergies is dramatically increasing due to changing environmental factors, such as pollution and climate changes, and growing numbers of immunological sensitive individuals in the general population. A majority of AC patients have mild recurrent episodes that flare up seasonally, called perennial conjunctivitis, but approximately 30% of ocular allergy patients suffer with intense and persistent symptoms that occur on a regular basis throughout the year.
OCULAR ALLERGY SYMPTOMS
Signs and symptoms of AC include tearing, itching, chemosis, conjunctival injection, papillary conjunctivitis and photophobia if the cornea is involved. When an individual becomes sensitized to a particular allergen, a cascade reaction triggers proallergic and proinflammatory mediators to stimulate itching and vasodilation in the eyes. Specifically, the cross bridging of IgE molecules initiates mast cell degranulation resulting in the release of histamine. Histamine binds with nociceptors, leading to the subjective complaint of itching.
Treatment of ocular allergy completely varies with severity. AC can be managed successfully with a stepwise approach by assessing the severity of the signs and symptoms. In many cases, it is necessary to target multiple pathways to achieve both acute and long term relief. You may also find yourself treating the condition under the confines of a patient’s insurance (see Docs Speak Out on page 32).
AVOIDANCE AND OTC MANAGEMENT
If an offending antigen can be identified (such as animal dander), potentially the best management is simple avoidance. This is often not possible and other modalities need to be employed. Patients that present with mild signs and symptoms will find relief from palliative treatment including cool compresses for five to 10 minutes BID and artificial tears as needed. The artificial tears will dilute the allergen and provide soothing relief, while cool compresses will trigger vasoconstriction in the affected area and diminish the blood-borne allergic response. Many patients with acute symptoms self-medicate with over-the-counter (OTC) oral antihistamines, however, this can lead to dryness and paradoxical worsening symptoms. Best results are achieved by using OTC topical ketotifen fumarate ophthalmic solution, such as Zaditor from Alcon Laboratories or Alaway from Bausch + Lomb, in addition to the oral antihistamine.
|Antihistamine/mast cell stabilizers
Alcaftadine: Lastacaft from Allergan
Azelastine: Optivar Ophthalmic from Meda Pharmaceuticals
Bepostastine: Bepreve from Bausch + Lomb
Epinastine: Elestat from Allergan
Ketotifen: Zaditor from Alcon; Alaway from Bausch + Lomb
Olopatadine: Patanol, Pataday and Pazeo, all from Alcon
ANTIHISTAMINE/MAST CELL STABILIZERS
A topical prescription combination antihistamine/mast cell stabilizer (see box below) is the best option for treating seasonal AC cases because of its dual action blocking the effects of histamine and prohibiting mast cells from releasing the chemicals responsible for allergy symptoms. Olopatadine is a favorite choice among practitioners because of its diverse mechanism of action (MOA) and effectiveness. In a recent study, 0.77% olopatadine hydrochloride ophthalmic solution (Pazeo from Alcon) was found to be superior to milder concentrations (Patanol and Pataday, both from Alcon) on rapid relief of ocular itching and conjunctival redness with no safety concerns. It is debatable whether prescription allergy drops are more effective than OTC agents. Similar efficacy was found between olopatadine and ketotifen in a 30-day trial comparing redness, chemosis and eyelid swelling, and both were effective in diminishing the expression of inflammatory mediators.
Mast cell stabilizers, such as nedocromil sodium ophthalmic solution (Alocril from Allergan) or Cromolyn Sodium Ophthalmic Solution from Bausch + Lomb, are acceptable for long term AC management, but they do not provide acute relief. Because it takes approximately four weeks of BID dosing before mast cell stabilizers become effective, it is best to supplement initially with a combination of palliative treatment, topical antihistamine or topical steroids/NSAIDs.
For moderate to severe AC, adding a topical steroid can enhance the effect of the antihistamine/mast cell stabilizer and relieve patient’s symptoms temporarily during an acute flare up. Steroids, such as loteprednol etabonate ophthalmic suspension (0.2% Alrex, 0.5% Lotemax or Lotemax Gel””all from Bausch + Lomb) or fluorometholone (FML from Allergan), are best to start with because of their safety profile and low intraocular absorption. Pulse therapy is appropriate for more severe cases, however, it is recommended to monitor IOP closely if using a steroid for longer than two weeks. Alrex is the only topical steroid approved for allergy treatment and has demonstrated long term safety.
|A topical prescription combination antihistamine/mast
cell stabilizer, such as Pazeo from Alcon, relieves
itching and reduces redness.
If steroids are contraindicated for a particular patient, topical NSAIDs such as ketorolac tromethamine (Acular LS and Acuvail””both from Allergan) or bromfenac (Bausch + Lomb’s Prolensa) are another option for temporary relief for one week while ramping up chronic AC management. Topical NSAIDs relieve itching by inhibiting cyclooxygenase, which is part of the inflammatory cascade, however, they do not block histamine. Therefore, topical NSAIDs should serve only as temporary relief for AC.
More severe forms of allergic conjunctivitis, including atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC), have more of an inflammatory response and require aggressive treatment. These patients often are treated initially with an extended pulse steroid therapy in conjunction with a mast cell stabilizer for long term management. Several studies have investigated the efficacy of topical immunomodulators such as cyclosporine A ophthalmic emulsion 0.5% (Allergan’s Restasis) and tacrolimus (Prograf from Astellas Pharma US, Inc.) for managing chronic AC. VKC and AKC have been found to respond to treatment within one month of initiating therapy of either cyclosporine A or tacrolimus and show significant improvement after six months of therapy. Tacrolimus therapy alone can significantly reduce corneal epithelial involvement in VKC patients. Both immunomodulators have a good safety profile and have minimal side effects. Although mast cell stabilizers have been the mainstay treatment for AKC and VKC, growing evidence indicates practitioners should consider an immunomodulator for severe AC cases.
The prevalence of ocular allergies is increasing in the general population, and eyecare providers need to be ready to handle not only the mild cases but also have a game plan for the more severe ocular allergy cases. Using a stepwise approach in managing ocular allergies will help you manage any severity of ocular allergies.
Lindsay Baker-Howse, OD, is a primary care/ocular disease resident and Joseph Sowka, OD, FAAO, is a professor at Nova Southeastern University in Fort Lauderdale, FL.
WHERE TO FIND IT:
Alcon Laboratories, Inc.
800.451.3937 | Alcon.com
800.347.4500 | Allergan.com
Astellas Pharma US, Inc.
800.888.7704 | Astellas.us
Bausch + Lomb
800-828-9030 | Bausch.com/ecp
732.564.2200 | MedaPharma.us