The scope of ocular surface disease is a vast territory which can be treacherous and confusing for even the most skilled clinician posed by a dry eye or “allergic conjunctivitis” case—or combination thereof. Why the quotation surrounding this popular condition? The simple reason is that until recently, the eyecare community utilized subjective data collection to diagnosis this multifaceted disease, albeit with great success.
What would be the response if I told you that prescribing an allergy medication outright was a bandage or knee-jerk approach? Now, before everyone comes after me with pitchforks, hear me out. I am not stating that you have violated the sacred Optometric Oath by mistreating the patient. The thought is to expand our horizons as a profession beyond its current bounds in a more objective manner.
Scoping it out
Statistically, there are 60 million Americans affected by allergies, of which 24 million (40 percent) have some form of ocular etiology.1-3 From a public health standpoint, this is a emerging epidemic in our society for which population-based studies show that the rate of allergenic disease is increasing in magnitude. The many faces of allergy encompass patients with classic seasonal and perennial allergic conjunctivitis to vernal keratoconjunctivitis, atopic keratoconjunctivitis, and giant papillary conjunctivitis.4
More from Dr. Cooper: 3 tips to navigate the allergy discussion with kids
Seasonal and perennial allergies cases are linked directly to the expression of specific immunoglobulin E (IgE) antibodies to environmental allergens making up the most common form of ocular allergy, affecting up to 15 to 20 percent of the population.5 In this type of ocular allergy, allergens interact with IgE bound to sensitized mast cells and after two rounds of exposure, result in a massive hypersensitivity reaction characterized by mast-cell degranulation. Consequent increased levels of histamine, prostaglandins, leukotrienes, and other pro-inflammatory molecules in the tear film in these mast cells trigger the expression of chemokines, adhesion molecules, and other cause these mast cells to trigger the expression of chemokines, adhesion molecules, and other chemoattractive proteins. The result is the recruit and activation of T-cells and macrophages in the conjunctival mucosa, characterizing the late-phase Type IV delayed reaction.6