Allergy season is one of those constants in Michigan; the same as death and taxes. Our eyes are often a good barometer of how sensitive we are to different allergens.

Allergens cause allergic reactions and can include grass, pollen, animal dander, contact lens solutions, dust and smoke. They can effect children and adults and be seasonal or year-round. Since they are so prevalent in Michigan, many allergy sufferers are also contact lens wearers.

The following are some basics of allergic eye conditions and how your optometrist, if board certified to prescribe medications, can help you be more comfortable.

The nasal corner of our eyes has one of the largest concentrations of cells that react and cause allergy symptoms. Called "mast cells" they release the compound histamine that triggers the allergic reaction causing redness, swelling and the characteristic itching.

Current allergy therapy can include:

1. Stabilizing the mast cells to prevent histamine from ever being released (mast cell stabilizers)

2. Blocking histamine, once released, from where it needs to go to cause the next step in the allergic reaction (anti-histamines)

3. Short-circuiting the allergic reaction once histamine has reached its receptors (steroids, non-steroid anti- inflammatories and vasoconstrictors)

The first group of drugs, mast cell stabilizers, are commonly used in nasal spray and eye drop form. They are very mild with few side effects so they can be taken long term, but they vary in effectiveness. Since they address the very beginning of the allergy reaction (mast cells releasing histamine) they are not useful in relieving allergy symptoms already begun. Patients must use mast cell stabilizers days before they will be exposed to allergens. And, they must be taken faithfully or the effect is lost.

I’m sure you’ve heard of the second group of drugs, antihistamines. These are found in most over-the-counter allergy pills and more recently non-prescription eye drops. These help relieve symptoms already present. If your family doctor approves, taking oral antihistamines alone may control itchy eyes. If not, adding over-the-counter antihistamine eye drops may help. These drops often include a vasoconstrictor (a drug to constrict the blood vessels on the white of the eye). These drops are for occasional use and shouldn’t be used long-term or with certain forms of glaucoma. Ironically, the vasoconstrictor component can lead to rebound increased redness if over-used.

The last group of drugs can be very effective. Mild steroids, unlike those abused by body builders, can be very useful in health care. Steroid eye drops work great short term but can cause increased pressure in the eye and cataracts with chronic use. A fairly new eye drop (acular) has a non-steroidal, anti-inflammatory agent similar to ibuprofen. This gives the advantages of a steroid with decreased side-effects. Steroids and related drops relieve symptoms after they have begun.

Allergy relief can sometimes be as simple as avoiding allergens. This can include staying in an air-conditioned area and avoiding freshly mown lawns for seasonal allergy sufferers. a cold washcloth held over the eyes and artificial tear drops to rinse the eyes can also be therapeutic.