The eyes are one of the most sensitive and vulnerable
organs in the body. Airborne allergens and other
particles can land directly on the surface of
the eye, causing irritation and redness. Eye allergies
are no different than allergies that affect your
sinuses, nose or lungs. When an allergen comes
in contact with your eyes, your body releases
histamine - a chemical produced in reaction to
a substance that the immune system can't tolerate.
Special cells called mast cells make histamine.
These cells are present throughout the body but
are highly concentrated in the eyes. Ocular allergens
tend to be airborne (as are most other allergens).
The most frequent allergic triggers include:
- Pollen
- Pet hair or dander
- Dust
- Some medicines
Conjunctivitis is an inflammation
of the conjunctiva (the membrane lining under
the eyelids) and can be caused by allergies. When
conjunctivitis is caused by allergies, both eyes
are usually affected. Common symptoms of allergic
conjunctivitis are:
- Redness and itching under the eyelid
- Excessive watering
- Swelling of the eyeball
The most effective treatment is prevention: try
to avoid the allergens that trigger symptoms.
For many, this is easier said than done, especially
if your triggers are airborne, such as pollen.
When ocular allergies can't be controlled, there
are several medications that may help relieve
symptoms. Most of these treatments come in a topical
form - such as eye drops or an ointment. Eye drops,
also called "tear substitutes," can help in two
ways: (1) by physically washing away allergens;
and (2) by moistening the eye, which can become
dry and red when irritated. Eye drops that contain
medications to help reduce allergy symptoms also
are available. Eye drops containing antihistamines
can reduce redness and swelling in the eye. Antihistamines
block the effects of the chemical histamine, which
is responsible for allergic symptoms like swelling,
redness and itching. Mild antihistamine eye drops
are available over the counter, but stronger ones
are available by prescription. Chilling any topical
medications can help relieve redness and itching
of the eyes. In addition, using cold compresses
can help reduce some of the discomfort associated
with conjunctivitis. A washcloth soaked in cold
water works well. |
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