Treating Ocular Allergy With Confidence
Therapies new and old offer an array of options for symptomatic relief.
By Robert Murphy, Contributing Editor
One of the nice things about treating allergic conjunctivitis is that its pathogenesis is so familiar that those who have devised and formulated its remedies know precisely where to target the therapy. This means that even treatments whose effect appears to be primarily palliative also possess therapeutic properties that address the condition's pathophysiologic facets. Clinicians can treat their patients with confidence that not only will the therapy be effective, but that it will work quickly and with a generally favorable safety profile. Which is precisely why patients come to you in the first place.
This holds both for the less-aggressive treatment measures such as artificial tears and cold compresses as well as the more interventionist topical anti-allergy medications and the so-called “soft” steroids. And remember, even as you focus on abortive measures, you can do your patients a favor by pointing out reasonable prophylactic precautions they can take to limit their exposure to whatever sets them off.
By now you've likely had a stampede of uncomfortable patients presenting with the severe itching that characterizes allergic conjunctivitis. For them, simply to walk in the park with a friend or partner is to invite unrelenting suffering. It doesn't have to be this way. Timely and effective treatment of allergic conjunctivitis is one more way by which you can significantly improve a patient's quality of life.
Artificial Tears, Cold Compresses
While topical antihistamine/mast cell stabilizers and topical steroids may be the heavy hitters when it comes to arresting the inflammatory cascade of ocular allergies, clinicians usually include artificial tears and cold compresses in the therapeutic mix. It might be fair to ask why. If anti-allergy drops and topical steroids are so effective in these cases, why bother with these less-potent measures?
Many clinicians take a stepwise approach to treating allergic conjunctivitis depending on the condition's severity. After all, some presentations are mild, with minimal redness, tearing and chemosis and itching that falls short of the torturous. “In some patients, symptoms are very mild,” says Cynthia Matossian, MD, a private practice ophthalmologist in Mercer County, NJ, and Bucks County, Pa., and an adjunct clinical assistant instructor in ophthalmology at Temple University. “Initially, a cold compress may help, or artificial tears to cleanse the eye of any pollen or irritants that may be clinging to their tear film.”
Recommend to the patient that the next time he or she has an urge to rub the eye, instead go grab a cold compress and find relief that way. It's a matter of breaking a self-perpetuating habit—which is easier said than done.
Topical Anti-Allergy Drops
Clinicians are fortunate to have at their disposal no fewer than seven safe and effective topical antihistamine/mast cell stabilizer medications. Two of them—Pataday (olopatadine 0.2 percent, Alcon Laboratories) and the recently launched Lastacaft (alcaftadine, Allergan)—are formulated for once-daily dosing. The others are Bepreve (bepotastine, Ista Pharmaceuticals), which has also shown effectiveness against allergic rhinitis, Elestat (epinastine, Inspire Pharmaceuticals)—soon to become generic—Patanol (olopatadine 0.1 percent, Alcon Laboratories), Optivar (azelastine, Meda Pharmaceuticals), and over-the-counter Zaditor (ketotifen, Novartis and other manufacturers). Note that Optivar and Zaditor are said to sometimes cause burning when instilled.
In practice, they all work well—and quickly. Studies show that these topical antihistamine/mast cell stabilizer begin to work within three minutes of use. “The dual mechanism of action relieves the itch right away due to the antihistamine component,” says Jodi Luchs, MD, of North Shore Jewish Medical Center in New Hyde Park, NY, and a private practitioner from Wantagh, NY. “It blocks the histamine receptors on the nerve endings in the conjunctival vasculature to blunt that allergic response. Blunt the itch, blunt the redness, blunt the swelling.”
These topical medications do double duty. “They also have a mast cell stabilizer that can help prevent mast cells from degranulating, from releasing those granules in the first place,” Dr. Luchs says. “By continuing to use them, they can help to prevent the next itch attack that you're going to get. Stabilize the allergic process to break the allergic inflammatory cascade. These drugs also have other effects further down the inflammatory cascade into the late phase, where they can block the chemotaxis of some of these cells and the activation of some other cells that would come into the area later in the allergic response.”
Those therapies approved for once-daily dosing may be especially useful for patients whose compliance may be questionable, as well as for contact lens wearers. It just makes life easier. For patients who are contact lens wearers, for example, they can just instill the drop once in the morning before putting in their lenses. That way, they don't have to worry about the itch resuming in the middle of the day, in which case they would have to remove the lenses, instill another medication drop, disinfect the lenses and put them back in. Contact lens wear is not contraindicated in allergic conjunctivitis “but many patients who have active ocular allergies find that they're intolerant of their contact lenses,” Dr. Luchs says.
Topical Steroids
Is a topical corticosteroid really necessary to treat garden-variety allergic conjunctivitis? Some wonder if that might be a bit of overkill.
Dr. Sheppard recognizes that the pathophysiology of severe allergic conjunctivitis practically demands that you come at it with a topical steroid. A topical antihistamine/mast cell stabilizer in such cases too often proves inadequate. “It's not just a type-1 hypersensitivity reaction, where you suffer the liberation of biochemical mediators from mast cells,” Dr. Sheppard says. “It also involves other types of immunity, including type-4 hypersensitivity, and destabilization of the endovascular barrier. In other words, the blood vessels become leaky. And the topical antihistamines won't touch that. Steroids are far more effective at addressing inflamed, hyperpermeable vasculature.”
Not everyone advocates the use of a topical steroid to treat allergic conjunctivitis. Some favor going with a nonsteroidal anti-inflammatory drug. “If it's just ocular allergies that I'm treating, sometimes I'll add a nonsteroidal anti-inflammatory,” says Barry Schechter, MD, director of Cornea and External Diseases and the Cataract Service at Florida Eye Microsurgical Institute. “In this country, when Acular (ketorolac, Allergan) was first given its indication, it was for allergic conjunctivitis.” Nowadays he prefers Bromday (bromfenac, Ista Pharmaceuticals), because it's the only once-a-day NSAID. “And it's very soothing. It doesn't burn when you put it in the eye” the way some other meds do.
Others stay away from topical steroids or NSAIDs altogether. Only in rare cases will Neal Barney, MD, use a topical steroid for allergic conjunctivitis. Dr. Barney is an associate professor of ophthalmology at the University of Wisconsin, specializing in cornea and external disease as well as ocular immunology. “I typically don't recommend a topical steroid for allergic conjunctivitis,” he says. “I believe, really, it's a rare case where garden-variety seasonal allergic conjunctivitis cannot be brought under good control with topical antihistamine/mast cell stabilizers. It's a benign disorder that's self-limiting over the six weeks of the allergy season. Even that short period of time for me is not a risk that warrants taking.”
Oral Antihistamines
No doubt you've observed that allergic rhinitis often accompanies ocular allergy. You're not alone. Allergic conjunctivitis occurs concomitantly with 90% of nasal allergies. Many patients may also experience a scratchy throat and wheezing. When the allergic repurcussions are multifaceted, many clinicians prescribe an oral antihistamine to battle the disease on several fronts. The common ones include Zyrtec, Claritin, Allegra, Singulair (montelukast, Merck), and Benadryl (diphenhydramine, McNeil), which causes drowsiness and is typically reserved for bedtime.
All oral anti-allergy agents are certainly effective, yet all but one cause significant ocular drying, which of course can worsen a preexisting dry eye. “As a result, I either try to avoid those or substitute another equally effective but non-drying agent like Singulair,” Dr. Sheppard says. Oral antihistamines also have a great safety profile, which means patients can use them regularly if necessary. With an oral antihistamine among the therapeutic mix, you can be confident that you have done all you can to keep the allergic cascade in check.
Avoid the Allergen
Of course, there's no better cure than prevention. There are some steps patients can take to avoid exposure to the offending antigen. Some of these are easy while others call for some sacrifice, perhaps even a diminution of the quality of life. Each individual must decide for themselves whether that's a trade-off worth making.
For one thing, who wants to be housebound, particularly at such a nice time of year? But patients whose allergies are bad enough may wish to spend more of their time indoors. Of course, this rules out any number of outdoor activities that may define what a good life is all about. A good idea for those who do choose to spend time outside—playing sports or gardening, for example—is to shower before bedtime. Advise patients to wash away those allergens that cling and hit the pillow with a pristine face.
A patient may wish to toss out the carpets and instead go with wood or tile floors. A tidy household with frequent vacuuming and dusting can only help.
Then there's the matter of pets. Here we have a really tough call. Those willing to part with their animal companion may have a family member or friend willing to house the little beast, at least perhaps during allergy season. You'll then at least have visiting priviliges, just in and out before the mast cells start to crumble. Then again, those sufficiently attached and intrepid in the face of danger will say, “Damn the symptoms, come here, Fluffy!” OM
Disclosures:
Dr. Matossian is a consultant and/or speaker for Abbott Medical Optics, Alcon Laboratories, Inspire Pharmaceuticals, Ista Pharmaceuticals and Allergan.
Dr. Schechter is a consultant for Ista Pharmaceuticals and Bausch & Lomb.
Dr. D'Arienzo is on the speakers bureau for Alcon Laboratories.
Dr. Barney has received a research grant from Alcon Laboratories.