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