Ocular allergies present practice-building opportunities

February 1, 2010

To build a large allergy practice; clinicians must have a thorough understanding of the different types of ocular allergy; the pathology; symptoms and recommended treatments.

Consider this:

• Ocular allergy affects an estimated 20% to 25% of the general population.

•To combat the symptoms, in 2007 Americans purchased more than 55 million units of over-the-counter eye drops and 8 million units of prescription ocular allergy medications, according to the American Optometric Association.

• The Allergy and Asthma Foundation of America reports that in 69% of cases, general practitioners prescribe allergy medications, with all specialty groups accounting for just 4% of prescribing.

To build a large allergy practice, clinicians must have a thorough understanding of the different types of ocular allergy, the pathology, symptoms and recommended treatments, he said.

A continuum of symptoms

Seasonal and perennial allergic conjunctivitis are by far the most common types of ocular allergy seen in optometric practice, usually accounting for more than 90% of all cases. Allergy typically presents in childhood with a second wave coming in adolescence. Since allergy is inherited, virtually all of these patients will have a family history of other allergic conditions.

"Ocular allergy occurs on a scale ranging from acute and transient to perennial and chronic," Dr. Epstein said. Although the manifestations of allergic conjunctivitis can severely impact the patient's quality of life, the condition itself typically is not vision–threatening. However, other, more severe forms of ocular allergy can be, Dr. Epstein noted.

The pathophysiology of allergic conjunctivitis is a type 1 IgE-mediated hypersensitivity. Prior sensitization is required for the allergic reaction to develop.

Mast cells in the conjunctiva mediate the immediate response to the allergen, whether it is cat dander, ragweed, or dust mites. The release of histamine and a host of other mediators from the mast cells cause the early phase response of ocular itching, watering and burning. A more damaging, late-phase response, involving infiltration of eosinophyls and basophils, may occur, but it is clinically irrelevant in acute ocular allergy.

Acute allergic conjunctivitis occurs suddenly on exposure to an environmental allergen. "Acute allergic conjunctivitis is self-limiting, and symptoms usually disappear within 24 hours," Dr. Epstein said. "Unless severe and persistent, most patients affected by acute allergic conjunctivitis typically do not seek treatment from a physician."

Acute allergic conjunctivitis occurs suddenly on exposure to an environmental allergen. "Acute allergic conjunctivitis is self-limiting, and symptoms usually disappear within 24 hours," Dr. Epstein said. "Unless severe and persistent, most patients affected by acute allergic conjunctivitis typically do not seek treatment from a physician."

Seasonal allergic conjunctivitis, or hay fever, is an acute reaction that occurs during the spring and fall pollen seasons. Perennial allergic conjunctivitis is a milder, year-round chronic affliction caused by indoor environmental allergens, such as mold or dust mites.

"Although patients may try over-the-counter topical antihistamines or vasoconstrictors, both seasonal and perennial allergic conjunctivitis are treated most effectively by prescription medications," Dr. Epstein commented. "That's the role of the eye-care professional."