ALLERGIES AND LENS WEAR
Treating Allergy in Contact Lens Patients
Whether your allergy patients suffer seasonally
or year-round, you can help improve their quality of life.
By Jeffrey Krohn, OD, FAAO
Almost
daily we face the challenging task of sorting through various potential causes for
a patient's difficulty obtaining comfortable contact lens wear. Don't simply try
the latest lens or solution on every patient who presents with complaints of discomfort
or irritation. Instead, listen to patients, carefully examine their ocular tissues
and process what you see to arrive at a proper diagnosis and treatment plan.
Too often in clinical practice, we can fall
into the habit of "seeing what we were expecting." To quote Douglas Adams, "A scientist
must be absolutely like a child. If he sees a thing, he must say that he sees it,
whether it was what he thought he was going to see or not. See first, think later,
then test. But always see first. Otherwise you will only see what you were expecting.
Many scientists forget that."
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Figure
1. Contact lens-induced papillary conjunctivitis.
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What Patients Tell Us
Patients presenting with ocular surface discomfort
usually describe different underlying causes using the same terms. Patients suffering
from blepharitis, dry eye syndrome, soiled lenses and allergic conjunctivitis might
equally complain of burning, itching, dry, sore, red or watery eyes. While you can
certainly glean valid information from a careful patient history (for example, a
complaint of lens dislocation and excessive movement with sporadic mucus suggests
contact lens-induced papillary conjunctivitis, Figure 1), deciding on a treatment
plan based on patient symptoms alone is careless and fraught with likely inaccuracies.
When it comes to ocular discomfort and contact lens wear, what you "see" is most
important.
However, it bears repeating that many contact
lens patients assume that a certain level of discomfort is unavoidable and part
of lens wear. Practitioners who never ask their patients how their eyes are feeling
may never unlock the door to even greater patient satisfaction through improvements
in their lens wearing protocol.
What to Look for
You should immediately perform a general inspection
of a patient's skin and face when greeting him. Signs of eczema, demonstrated by
dry, thick, red areas, would certainly indicate a patient who has an allergic or
atopic profile. Document rhinophyma when observed. Scrutinize the meibomian glands
exhaustively to ascertain their impact on the comfort of the eyes and the possibility
of rosacea-related ocular discomfort. A pronounced dermatitis on the superior lids
tends to result from airborne irritants and responds well to antibiotic/steroid
combination ointments. On the other hand, a dermatitis on the lower eyelid surface
typically results from substances that are put on or in the eye. These cases warrant
a very careful history of all drops, ointments and make-up the patient has been
using.
When
moving in closer to observe the ocular structures, it's best to begin with dry eye
in mind. Observe the blinking pattern and regularity, the cleanliness and orderliness
of the lashes, the regularity and smoothness of the lid margins and their apposition
to the globe. Be familiar with the normal appearance of the lacrimal lake and what
constitutes a reduced volume. When observation reveals dry eye syndrome, blepharitis
and/or meibomian gland dysfunction, lens-wearing patients often respond quite well
to traditional treatment modalities (lubricants, cyclosporine, lid scrubs and/or
punctual plugs).
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Figure
2. Bulbar conjunctival erythema. |
The bulbar conjunctiva will
typically show pink, diffuse erythema in an allergic response (Figure 2). However,
in a variant of what dermatologists call "white dermatographism," you can expect
the edematous response of the conjunctiva to overpower the capillary dilatation
and somewhat obscure it. Careful slit lamp optic section observation of the bulbar
conjunctiva should reveal chemosis in a true allergic response. While frank chemosis
is easily identified by its thick and bullous presentation, subtle chemosis likely
goes undetected in many clinical encounters. To detect the mildest cases of chemosis,
instill fluorescein (sparingly) and observe the surface of the eye with a yellow
"blue blocking" filter (Tiffen or Wratten 12). With practice, you'll become quite
adept at differentiating subtle wrinkling of the bulbar conjunctival surface from
mild chemotic responses (Figure 3).
Application of fluorescein can also
help differentiate other possible causes of ocular discomfort. Corneal staining
should be taken quite seriously and may indicate concurrent conditions such as dry
eye syndrome, medicamentosa, contact lens mechanical effects or bacterial exotoxin
production. Allergic conjunctivitis does not typically cause corneal staining or
inflammation. If you see peripheral infiltrates (Figure 4), think of a hypoxic or
infectious contact lens-related etiology. The cornea is involved in only the most
severe forms of allergy and atopy (vernal keratoconjunctivitis and atopic corneal
ulceration).
The palpebral conjunctiva is typically
evaluated last in the biomicroscopic routine, with the lower lids retracted from
the globe for examination and the upper lids everted to inspect the superior palpebral
surface. The superior conjunctiva is firmly attached to the tarsal plate, which
leaves little room for lymphatic follicles to protrude from the surface. Therefore,
a follicular/lymphatic response of the ocular surfaces will be more pronounced in
the inferior cul-de-sac and to the "sides" of the superior tarsal plate in the superior
region. Allergic responses typically demonstrate mild to moderate follicular response
inferiorly with a subtle increase in the papillary appearance superiorly.
After gathering all of the information,
assess the patient's level of symptoms and signs to arrive at the appropriate diagnosis.
When treating lens-wearing patients who suffer from allergic conjunctivitis, your
goal is to "clean up and quiet down" the ocular tissue/lens interaction. You can
achieve this by quieting down the eye and then keeping the eye quiet by prescribing
cleaner solutions and cleaner lenses and attempting to clean up the environment
around them.
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Figure
3. Subtle conjunctival chemosis.
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Quieting Down the Eye
Discontinue Contact Lenses When
objective signs of allergic conjunctivitis are present, discontinuing lens wear
can prove helpful. In addition to removing a "landing site" for allergens, it serves
as a provocative test for other potential irritants (solution intolerance, corneal
exhaustion, etc.). In cases where total discontinuation is impractical or unlikely,
a trial course of daily disposable lenses works for a majority of patients. In mild
cases, when added to other treatment methods, reducing wearing time may be sufficient.
Cold Compresses Applying cold
compresses to the closed eyelids has been a treatment mainstay for ocular irritation
from allergies for many years. This simple and economical approach can bring relief
to even the most severe presentations. Crushed ice, fluid-filled masks and even
frozen vegetables (peas, corn or carrots) sealed into a plastic bag can create a
good cold compress.
Antihistamines The availability
of numerous antihistamine ophthalmic preparations allows a very direct approach
to minimizing the symptoms of allergies. It's prudent to choose products that have
good efficacy on a b.i.d. dosage if the patient will continue with contact lens
wear through therapy.
Mast
Cell Stabilizers The suppression of the mast cell response is one of the
most powerful ways contact lens practitioners can truly suppress an allergic reaction.
Unfortunately, many products that were originally formulated to work on the mucousal
membranes of the "airway" have little effect on stabilization of mast cell response
in human conjunctival cells. Although manufacturers debate their technical equivalency,
the combination drops olopatadine (Patanol, Alcon Laboratories), epinastine (Elestat,
Allergan) or ketotifen (Zaditor, Novartis Ophthalmics) perform clinically well on
a b.i.d. dosage regimen for lens wearers who have signs or symptoms of ocular allergies.
Many practitioners have found good success with Patanol when used on a q.d. basis
(one drop in the morning) for mild presentations.
Keeping the Eye Quiet
Cleaner Solutions The steadily
increasing use of silicone hydrogel lenses has brought back a renewed interest in
both the dynamics of contact lens fitting and the intricacies of contact lens solution
chemistry. In general, patients who have allergic conditions will benefit from contact
lens solutions that minimize the exposure to potentially toxic, sensitizing or drying
components. The holy grail that we're all waiting for is a disinfectant that has
a maximum impact on organisms of concern with little chance of ocular irritation
or sensitivity in an easy-to-use system. Peroxide-based products have come the closest
to this goal in the past. While ultraviolet and ultrasonic mechanized units have
given peroxide a run for its money as the "cleanest solution," they haven't caught
on with patients or practitioners.
The
residual levels of peroxide present in a solution after neutralization, along with
consistent patient preference for the ease of use of multipurpose solutions (MPS)
has led most manufacturers to pursue development in this category. Currently, new
MPS formulations offer great assistance to practitioners who want to minimize lens
solution interactions with the ocular tissues. Bausch & Lomb's ReNu with MoistureLoc
is a notable improvement over its former formulation, as is Advanced Medical Optics's
Complete MoisturePlus and CIBA Vision's introduction of Aquify to replace SoloCare
Plus. Alcon's new Opti-free Replenish has only recently become available to practitioners,
but promises to improve lens wettability and therefore lens cleanliness and comfort
through an enhanced interaction of lens surface and tear film. It bears repeating
that you should strongly discourage the use of obsolete, older formulations especially
in cases of ocular discomfort and that patients should use a digital rub and rinse
when experiencing lens discomfort.
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Figure 4. Peripheral infiltrates. |
Cleaner Lenses
For many years, the manufacturing process has received the most attention regarding
new developments in contact lenses. The last decade has seen renewed attention to
the lens materials themselves to the delight of practitioners and, when the lenses
are properly utilized, their patients. As is true for most new products, silicone
hydrogels don't provide the "end all, be all" that many projected. But they do provide
a significant advantage over traditional hydrogels in the critical area of corneal
oxygenation and you should consider them for appropriate patients. It's still too
early to tell if certain silicone hydrogels provide significant advantages over
others for contact lens patients who have allergic conditions.
However, you should pay careful attention
to research that attempts to differentiate the currently available lenses based
on their wettability and moisture retention characteristics. Traditional hydrogel
lenses containing a phosphorylcholine (PC) head-group, such as CooperVision's Proclear
Compatibles lens, have proven to retain moisture well and provide better end-of-day
comfort than other traditional hydrogel lenses. In general, a Group II (non-ionic,
high water content) lens will also perform better for allergic situations. The use
of daily disposable lenses, either seasonally or on a long-term basis in those patients
who experience allergic signs or symptoms, is also an excellent choice. The addition
of enhanced polyvinyl alcohol (PVA) to CIBA's new Focus Dailies with AquaRelease
has made this lens an even better choice than it already was for patients who experience
allergies and ocular discomfort.
Cleaner
Environment Although easier said than done, patients can best eliminate
allergic reactions by avoiding the offending particulate. Because many allergic
responses result from allergies to dust mites, service companies have attempted
to make homes or offices "allergy free" through the intense cleaning of heating
ducts, removal of drapes and carpets and other such techniques. Replacing feather
pillows with a newer hypo-allergenic design is a wonderful suggestion to patients
who have maximum symptoms upon awakening. A small desk-top humidifier in the office
or next to the home computer can increase moisture in the air enough to reduce the
exposure of the ocular surface to the allergens that become so problematic. Patients
may need to learn the times of the year or specific occasions during which their
contact lens wear is likely to be most problematic. By giving them tools to deal
with these situations: a supply of daily disposables, a prescription for ocular
medications and instructions for quick symptom reduction using a cold compress,
you provide them with the benefits of your training and experience to enhance the
quality of their daily life. It may be a cruel world out there, but it doesn't have
to be cruel to their contact lens wear.
Dr. Krohn is in a partnership practice in Fresno,
CA. He is a Vision Source! doctor and a diplomate of the Cornea and Contact Lens
Section of the American Academy of Optometry. He has served as a consultant and
conducted clinical research for the contact lens industry.
Contact Lens Spectrum, Issue: April 2006