a 12-year-old female, presented with complaints of recent ocular irritation. We
practice in a rural setting in West Texas where symptoms such as these are very
common. Further questioning revealed that her primary complaint was itching, but
she also experienced peri-orbital swelling. Her general health history was significant
for seasonal allergic rhinitis; she took Zyrtec (cetirizine, Pfizer) once daily
for nasal congestion and allergies. She took no other medications.
Visual acuity measured 20/20 in both eyes. Pupils, confrontation
fields and ocular motility were all unremarkable. Gross external examination showed
injected conjunctiva. The inferior lids were noticeably edematous, and the patient
repeatedly rubbed her eyes and nose during the examination (figure 1, page 48).
Biomicroscopy revealed mild conjunctival edema, injection
that was most prominent in the horizontal meridian, and injected, thickened lid
margins. Neither the cornea nor conjunctiva stained with sodium fluorescein. Examination
of the lower tarsal conjunctiva revealed multiple papillae (figure 2); upon eversion,
the upper lid had a similar appearance. I didn't see any giant papillae (>1mm
I diagnosed uncomplicated allergic conjunctivitis associated with
allergic rhinitis. The patient said she experienced no relief of her ocular symptoms
from the oral antihistamine. We prescribed palliative measures of cool compresses,
q.i.d. topical Systane drops (Alcon), and Patanol 0.1% ophthalmic drops (olopatadine
hydrochloride, Alcon ) q.12 hours. One week later, the patient's conjunctival edema
and injection had diminished considerably. She reported that her ocular itching
was greatly improved and her other symptoms has resolved completely.
Lauren's presentation is amazingly common. The incidence of allergy
in general, and ocular allergy in particular, has increased over the past decade.
According to the American Academy of Allergy, Asthma, and Immunology, 80 million
people experience ocular allergy, and the incidence appears to be rising. Consider
these statistics from the National Institute of Allergy and Infectious Diseases:
More than 50 million Americans suffer from allergic diseases.
►Allergies are the sixth leading cause of chronic disease in the United States and
cost the health care system $18 billion annually.
►The estimated prevalence of atopic dermatitis in the United States is 9% and appears
to be increasing.
►Chronic sinusitis, the most commonly reported chronic disease in the United States,
affects approximately 38 million individuals, or 12.6% of population.
►Approximately 90% of patients with rhinitis experience at least one day of ocular
symptoms per week.
More than just itchy eyes
1: Patient shows swelling of lower eyelids, which is characteristic of seasonal
The increased prevalence of allergy has a direct effect on quality
of life (QOL). A study of 377 adults with confirmed allergy asked participants to
complete an SF-36 Quality of Life Health survey prior to treatment initiation. The
survey measured eight QOL dimensions, including physical functioning, role limitation
due to physical problems, role limitations due to emotional problems, social functioning,
mental health and general health. All subjects had lower (poorer) scores on all
scales compared with norms for the general U.S. population. After one year of treatment
with allergy shots and an elimination and/or rotation diet, a second survey of the
same subjects revealed improvement in all areas.
findings suggest that allergy symptoms affect QOL and that treatment may lead to
measurable improvements. The authors concluded that doctors must recognize the QOL
impact of allergy and offer patients treatment.
A British study of the impact of ocular allergy on QOL showed
that individuals with seasonal allergic conjunctivitis (SAC) generally have a lower
income because they more frequently miss work due to symptoms. These patients also
reported a greater degree of ocular pain and discomfort than the control group.
Interestingly, in a country with socialized health care, the out-of-pocket health
cost for SAC-related care was £61 ($106.75) for control subjects and £124
($217) for the SAC group. The researchers concluded that SAC is common, costly,
chronic and causes reduced ocular and general QOL.
PAC Vs. SAC
Ocular allergy is rarely sight threatening. Rare conditions such
as atopic keratoconjunctivitis or vernal keratoconjunctivitis have the potential
to cause tissue damage and vision loss, but are not the focus of this article. The
vast majority of cases are SAC or perennial allergic conjunctivitis (PAC). As its
name suggests, SAC peaks during times of pollen release: typically spring and fall.
Perennial allergy persists for more than nine months.
These conditions are not mutually exclusive; in fact, it's common
for PAC patients to experience seasonal worsening of their condition during high
While pollens predominate as the causative agents in SAC, molds,
animal dander and dust mite droppings are the primary allergens in PAC. Dust mites
are unable to drink water and must obtain moisture from their environment. They
are rare in climates where humidity levels fall below 50%. Animal dander consists
of fur and shed skin particles. The primary allergen in animal dander is protein
derived from animal saliva. These agents tend to be present in the home year-round.
2: Notice the multiple papillae on the lower tarsal conjunctiva
Get to know the process
Successful management of ocular allergy depends on a thorough
understanding of the allergic process. Allergy is an inappropriate immune response
to a relatively harmless substance. When an allergen encounters a B-lymphocyte,
the cell is converted into a plasma cell that produces immunoglobulins (IgEs) specific
for the allergen. These IgEs reach the circulation and eventually adhere to the
surface of mast cells.
When the allergen encounters a sensitized mast cell and bridges
the gap between two molecules of IgE, the mast cell releases pre-formed granules
of pre-formed mediators into the environment. These granules contain histamine as
well as chymase, tryptase, heparin, eosinophil chemotactic factor, and neutrophil
chemotactic factor. Antihistamines effectively block the action of histamine on:
►nerve endings (itching)
►blood vessel walls (injection and leakage of fluid into the extravascular tissue,
which can lead to chemosis) and
Antihistamines do not influence the effects of other, preformed
Systemic antihistamines do not reach the eye in concentrations
comparable to those achieved with topical medications. In fact, they may worsen
ocular allergy symptoms because their drying effects can reduce tear volume and
thus increase the concentration of pollens on the ocular surface. OTC topical antihistamine/decongestants
reduce injection, but their effects are limited to only a few hours, after which
rebound injection often occurs.
Research has demonstrated that mast cells in the lungs, which
contain tryptase but not chymase (MT cells), behave differently from skin and conjunctival
mast cells that contain both tryptase and chymase (MTC cells). There are also inherent
differences in the way these types of mast cells react to medications. Topical "mast
cell stabilizers" were originally developed for pulmonary disease and exert very
little mast cell stabilization in MTC cells. For this reason, their usefulness in
managing SAC and PAC is limited.
Steroids exert their palliative effects on allergy symptoms by
blocking protein synthesis. Pulse doses of steroids for the initial quieting of
SAC and PAC is acceptable therapy, but long-term use is not recommended. This palliative
effect takes time, and the potential complications of chronic steroid use include
IOP elevation and cataract formation.
In 1997, Alcon introduced Patanol, the first topical allergy medication
that incorporated mast stabilization and antihistaminic effects. Other manufactures
subsequently introduced Zaditor (ketotifen fumarate ophthalmic solution solution,
0.025%, CIBA Vision), Optivar (azelastine hydrochloride ophthalmic solution, 0.05%,
Bausch & Lomb) and Elestat (epinastine hydrochloride 0.05%, Inspire). These
products were initially developed for systemic dosing, and are approved as topical
antihistamine/mast cell stabilizers.
While all four medications are superb antihistaminic agents, research
demonstrated that with the exception of Patanol, the combination antihistamine-mast
cell stabilizers did not effectively inhibit mast cell degranulation at their marketed
Adjunct palliative measures often enhance the actions of topical
allergy medications. Cold compresses constrict conjunctival vasculature, and frequent
use of non-BAK (benzalkonium chloride) preserved artificial tears dilutes the concentration
of allergen in the tear film. Thus I included both in my patient's treatment,
as I discussed above.
Better QOL for both of you
Ocular allergy is a very common, chronic condition that can negatively
affect our patients' quality of life. Effective management of allergic symptoms
and conditions can improve their lives. And as my many grateful allergy patients
will demonstrate, resolving their complaints will serve to grow your therapeutic
References available upon request.
practices in multiple locations. He served for 11 years
as a consultant at the VA Medical Center in Amarillo, Texas. He is Distinguished
Visiting Clinician in Residence at the University of Houston College of Optometry
and also serves as an adjunct faculty member there.