Article Date: 2/1/2006

allergy
How to Manage Ocular Allergies During the Off Season...
It may not be the peak time for patients to complain, but signs and symptoms tell a different story.
KELLY KERKSICK, O.D.

Allergies are everywhere. They come from a multitude of places and are certainly not limited to pollens in the spring. Allergic reactions can stem from laundry detergents, pet dander, cosmetics, contact lens wear, and a variety of other things that patients are exposed to environmentally. Ocular allergies are one of the most common conditions that patients present with in the exam chair, yet allergic conjunctivitis often goes undiagnosed and untreated. According to the 2003 – 2004 Gallup Study of Allergies, 50% of the U.S. population sufferers from allergies and 83% of those experience ocular symptoms. It is estimated that eight out of ten patients with systemic allergies also have ocular manifestations of the disease.

Needless to say, there are thousands of patients who suffer from the aggravating and distracting side effects that plague our allergy patients.

There are a wide variety of oral, topical, and nasal medications available to assist in relieving these aggravating symptoms. A number of effective prescription medications have become available over the counter (OTC) in the last decade. Knowing that there are a number of OTC medications that can offer relief makes treatment dilemmas much easier to solve.

The allergic response

As practitioners, it is much easier to manage ocular allergies if we understand how the allergic response takes place. During the course of an allergic reaction, a series of cellular processes take place that cause histamine, the chemical messenger mediating these cellular reactions, to be released, resulting in an allergic and inflammatory reaction. The mast cell plays a key role in this reaction. It is estimated that there are approximately 50 million mast cells in each eye. Mast cells house high concentrations of histamine, stored in granules inside these cells. This stored histamine remains granular and inactive until allergies bind to the histamine receptors. Once the allergy binds to the histamine receptor, the mast cell degranulates, releasing the histamine that causes the allergic reaction.

We know that histamine is released in response to stimuli such as bacterial toxins, venoms, trauma, allergies, or anaphylaxis. Upon its release, histamine binds to two types of receptors located on the cell surface; H-1 and H-2. H-2 receptors mediate gastric secretion and do not play a major role in ocular allergy. H-1 receptors aid in the production of smooth muscle contraction and increased capillary permeability.

The allergic symptoms that our patients experience are a result of the release of cell mediators such as histamine, serotonin, leukotrienes, and the eosinophil chemotactic factor associated with anaphylaxis. These cell mediators have the ability to cause a localized allergic reaction confined to one area like the skin, the eyes, or the respiratory tract. Histamine causes the vascular endothelium to release nitric oxide, the chemical messenger that stimulates cGMP production, which results in vasodilation. Under other conditions, cell mediators such as histamine can be released so quickly that inactivation can't occur, resulting in a full blown anaphylactic reaction.

Therapeutic intervention

One form of therapy used to manage ocular allergies is Histamine H-1 receptor blockers, more commonly known as antihistamines. Antihistamines work to block the histamine receptors from reacting to the target tissue, which is the allergy. These compounds do not have any impact on the formation or release of histamine. Instead, antihistamines work to block the cell-mediated response from occurring. It is this response that allows the allergic reaction to take place.

Most H-1 receptor blockers are well-absorb-ed after oral administration, reaching maximum efficacy one to two hours after ingestion. Since H-1 receptor blockers are not very site specific, be aware of some of the potential side effects and interactions that can occur with antihistamine use. Antihistamines interact with not only histamine receptor sites, but also with muscarinic receptors, alpha-adrenergic receptors, and serotonin receptor sites. As a result, these antihistamines cause a number of undesirable side effects, including sedation, dry mouth, blurred vision and dry eye problems for our patients.

Another common form of therapy used to manage ocular allergies is the mast cell stabilizer. Mast cell stabilizers prevent mast cells from degranulating, which also prevents histamine from escaping, thus forfeiting the cause of the allergic reaction. One of the benefits that mast cell stabilizers provide is the ability to offer long-term relief to the patient. Typically, this category of drugs is quite effective when dosed bid. Despite the benefit of the drug dosage schedule, one of the pitfalls of mast cell stabilizers are that they take at least two weeks of consistent dosage before the patient experiences the benefit of the drug.

In the event that there is an inflammatory reaction in addition to the allergic reaction, NSAIDs and steroidal therapy are warranted. NSAIDs and steroidal treatments are designed to reduce inflammation, which can contribute to all of the aggravating symptoms that comprise the allergic reaction. These drugs do an excellent job of getting rid of most of the aggravating physical characteristics of ocular allergy such as chemosis, edema, and injection.

Initiating a treatment plan

There are certain factors you should consider prior to initiating a treatment plan. Even though a large number of patients consciously experience discomfort secondary to their allergies, there are a number of patients who dismiss these aggravating symptoms as normal and never complain in the exam chair. Treat all allergy patients according to their individual needs. In the milder presentations, I often encourage the patient to keep an artificial tear like on hand.

If the patient complains of discomfort secondary to itchy eyes, an antihistamine or combination antihistamine/mast cell stabilizer drop can provide a rapid onset of relief. If the patient has no complaints of itching or discomfort, but the signs you see throughout the examination warrant treatment, I recommend initiating treatment based on clinical findings. Milder presentations of the disease are easily managed with artificial tears or a topical antihistamine/mast cell stabilizer combination. More advanced presentations warrant more aggressive treatment. In these cases, I have found that quicker healing is attained with topical steroid treatment. Topical steroids generally alleviate the inflammation and redness, and work to reduce the papillary response that creates the itchy eyes. A steroid such as Lotemax (loteprednol etabonate 0.5%, Bausch & Lomb) can resolve the inflammatory response very quickly with a low relative risk of side effects, such as increased IOP.

For more advanced cases, place the patient on Lotemax 1 gtt, q.i.d. for two weeks, then reduce the dose to bid for two more weeks. Reevaluate the patient's condition at the end of one month to determine how effective the therapy has been. Take IOP readings to rule out an increase in IOP as a result of the steroid use. At this time, if the papillae have resolved and the inflammation has dissipated, discontinue the steroid and start a combination mast cell stabil-izer/antihistamine drop such as Patanol (olopatadine hydrochloride, Alcon) or Elestat (epinastine hydrochloride, Inspire Pharmaceuticals/Allergan) to maintain control of the allergy. In the event that the patient experiences a flare-up or notices the return of their symptoms upon re-evaluation, try 1 gtt of refrigerated Alrex (loteprednol etabonate 0.2%, Bausch & Lomb) daily in conjunction with the mast cell stabilizer/antihistamine combination. As a rule, I never keep patients on a steroid longer than one month without monitoring them very closely.

If a patient has a severe allergic reaction to something specific such as a bug bite, an NSAID can reduce a lot of the swelling at the skin's surface. If a patient is really atopic and swollen, I always encourage them to take an OTC NSAID to help with inflammation, in addition to following the prescribed anti-allergy medications.

If we really evaluate where allergies come from, it makes perfect sense that patients of all ages are afflicted. In my experience, one of the most overlooked patient populations is children. Children often do not complain about the symptoms that accompany allergic conjunctivitis, mainly because they aren't capable of differentiating between eyes that feel normal and eyes suffering from allergies.

Often times, one of the key signs of ocular allergy in children is the observation that they are rubbing their eyes. Unfortunately, this telltale warning sign can often be misinterpreted as tiredness. Redness or inflammation is often misdiagnosed as pink eye. I have had a number of pediatric patients report to my practice after being treated by their pediatrician for pinkeye. Parents enter the practice with their children who have complaints of redness that never go away. Often times, these children are suffering from severe allergies that leave their eyes red, irritated, and mattered. Usually, a simple upper and lower lid evaluation confirms the diagnosis of an allergic problem.

Coding and practice management

Optometrists across the board are guilty of not billing for their time or their services. It has been my experience, that diagnosing, treating, and billing for ocular allergies can be quite beneficial to your practice. Your profitability will definitely increase as you start to see these patients on a more regular basis. The disease requires continual monitoring throughout the year. Generally, when I first see a patient in the office for an ocular allergy problem, I will see them for a follow-up at one month, and every four to six months thereafter.

Most importantly, I have gained some of my most loyal patients through detection and treatment of an allergic problem. Patients find the symptoms that accompany ocular allergies to be frustrating and uncomfortable. Many have gone for years without treatment or education as to the cause of the problem. It's a great feeling to know that you were able to improve a patient's quality of life by making their eyes comfortable again.

Dr. Kerksick is in private practice in Columbia, Illinois. She is also an active member of the Illinois Optometric Association and the IOA's political action committee. Send e-mail to kerksickod@yahoo.com.



Optometric Management, Issue: February 2006