By Beth Longware Duff; reviewed by Gary Heiting, OD

If you suffer from allergies, you've probably tried allergy eye drops or are thinking about giving them a try to relieve your ocular allergy symptoms.

This article will help you understand more about allergy eye drops and whether they might be helpful to give you relief from your itchy, watery, swollen or red eyes.

What causes eye allergies?

An allergic reaction occurs when a person’s immune system reacts to an allergen (irritant) in the environment, either indoors or outdoors. An allergen is any substance that causes allergy symptoms in sensitive individuals.

When confronted by an allergen, the immune system perceives it as an invader and goes into overdrive to produce histamines to fight it. This is known as an allergic reaction.

There are two basic categories of allergic reactions:

1. Seasonal allergies. These are due to allergens found in nature — such as mold spores and pollens from trees, grass and weeds. People with seasonal allergies usually notice that their symptoms worsen when they go outside on days when pollen counts are high.

2. Year-round allergies. These are due allergens that are typically found indoors, like dust mites, pet dander, mold and mildew. Symptoms for people with year-round allergies usually become more noticeable when they do things that set the allergens in motion, like brushing a pet or cleaning house.

The good news is that there are several effective allergy eye drops that can help reduce allergic symptoms.

How allergy eye drops can help

There are two main categories of allergy eye drops:

• Non-prescription allergy eye drops. Also called over-the-counter (or "OTC") eye drops, these can be purchased without a prescription from a doctor.

• Prescription allergy eye drops. These are medicated eye drops that require a prescription from your GP.

The best allergy eye drops for you depends on several factors, including the cause of your allergy and the severity of your symptoms.

Some allergy eye drops are formulated for short-term use for acute symptoms, while others are designed for long-term use to prevent symptoms from occurring or reduce your sensitivity to allergens.

The best allergy eye drops are those that work two different ways, says Tammy Than, OD, FAAO, and spokesperson for the American Academy of Optometry.

“These drugs work as an antihistamine — which helps with the itching, swelling and redness — and are also mast cell stabilizers which help prevent further release of chemicals that cause the allergies,” she says. “So these drops help with current symptoms and prevent future symptoms.”

Types of allergy eye drops

There are a number of different types of allergy eye drops. Ask your eye care professional for help to determine the best, most effective allergy eye drops for your needs.

Antihistamine eye drops

Antihistamine eye dropsare usually the first suggested treatment when symptoms become too strong to handle without medication.

Antihistamine eye drops block histamines in the body and quickly reduce symptoms like itchy, watery eyes. But the relief they provide may last only a few hours; so multiple doses throughout the day may be required.

Anti-inflammatory allergy eye drops

Anti-inflammatory allergy eye drops include nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. NSAID eye drops affect nerve endings, reducing itchiness within an hour after use.

Anti-inflammatory allergy eye drops may cause burning or stinging when first administered.

Corticosteroid eye drops

Corticosteroid eye drops are prescribed for treating long-term or severe eye allergic reactions.

Corticosteroid eye drops are usually recommended for short-term use because possible side effects include cataracts, glaucoma and high eye pressure (ocular hypertension).

Mast cell stabilizers

Mast cell stabilizers are another type of allergy eye drops. Mast cell stabilizers work by preventing the release of histamine and other chemicals produced by the body during an allergic reaction.

Mast cell stabilizers may be used for months without side effects, and they may allow contact lens users to continue wearing their contact lenses comfortably throughout allergy season.

Multiple-action allergy eye drops

Multiple-action allergy eye drops, also known as dual-action eye drops, combine more than one type of medication. The antihistamine/decongestant combo treats itchy, watery and red eyes.

Another version of multiple-action allergy eye drops combines an antihistamine and mast cell stabilizer. These multiple-action allergy eye drops can be used twice a day.

Once-a-day prescription multi-action drops are safe for long-term use during allergy season or for year-round allergies.

Decongestant allergy eye drops

Finally, decongestant allergy eye drops reduce the red, bloodshot appearance of the eyes affected by allergic conjunctivitis. These products work by reducing the size of dilated blood vessels under the conjunctiva.

Decongestant allergy eye drops should be used for only a short period of time due to the risk of “rebound hyperemia” — redness that returns after the drops are used frequently for a period of time and then are discontinued.

Follow the directions on the label

Whichever allergy eye drops you choose, always follow the instructions for recommended use on the label to minimize the risk of irritation and other side effects.

Limit your use of allergy eye drops to what the label specifies (usually 2-3 times per day). If the drops cause increased redness or irritation, consult your eye care professional immediately.

See your eye care professional

With so many allergy eye drops available, it can be nearly impossible to choose the best brand and formulation for your needs.

For the greatest relief from eye allergy symptoms, schedule a comprehensive eye exam with an eye care professional to determine the best allergy eye drops for you.

FIND AN OPTICIAN: if you're concerned about your vision, visit an optician near you.

Page published on Monday, 14 March 2022