Clinical Consultations: Ocular Allergy

Ocular Allergy

C. Stephen Foster, M.D.

There are five types of ocular allergy. These are:

1. hay fever conjunctivitis
2. perennial allergic conjunctivitis
3. giant papillary conjunctivitis
4. vernal keratoconjunctivitis
5. atopic keratoconjunctivitis

Although ocular allergy is often trivialized, by patient and doctor alike, the last two types of ocular allergies listed above have potential blinding capabilities. Even the more trivial first three types of ocular allergy listed can be aggravating enough to significantly impair the quality of the patient's life.

Hay fever conjunctivitis typically occurs in the individual with sensitivities to air borne allergens such as pollens, dust, and animal danders. It is typically seasonal, unlike its year-long cousin, perennial allergic conjunctivitis. Both seasonal allergic or hay fever conjunctivitis and perennial conjunctivitis are pure, simple allergic reactions to materials usually not producing such reactions in the normal population. The symptoms of exposure to the material to which the individual is sensitive include: itchy, running nose with sneezing, itchy, watery eyes, and ocular burning. Noticeable signs include mild conjunctival redness, excess mucus production, and tearing. If the person's "season" for seasonal allergic conjunctivitis is brief (for example, to pollinating trees in Spring only; or to ragweed pollen in Autumn only) then avoidance of the allergen and use of systemic and topical antihistamines is generally all that is needed for treatment to achieve reasonable comfort. An allergist is generally the physician best qualified to investigate and determine to which allergens the patient is sensitive, and to prescribe a systemic antihistamine. Topical antihistamine for use in the eye is generally almost instantaneously effective for ocular itch, though it may need to be applied several times throughout the day. An allergist or an ophthalmologist will generally be the physician prescribing such medication. Steroid drops should virtually never be used in the treatment of these mild conditions. Topical mast cells stabilizing agents (Nasalcrom or Azalastine for the nose or Patanol or Elestat for the eye) are additional treatment strategies that can be extremely useful for patients in whom the "season" of sensitivities is more than just brief.

Giant papillary conjunctivitis typically occurs in allergy-prone individuals who wear soft contact lenses. It can occur in individuals who wear other types of contact lenses, but it is more common in soft lens wearers. It occurs as a result of adherence of airborne allergens onto the surface of the contact lens, with eventual development of bumps in the conjunctiva lining the upper eyelid as the allergic/inflammatory response develops over a period of months. The symptoms of this disorder include decreased comfort with contact lens wear, mild itching, excessive contact lens movement, and excessive mucus production. Treatment for this condition generally involves, at the very least, obtaining new contact lens and employing a very aggressive, scrupulous daily lens scrubbing/hygiene program, and enzyme treatment of the lenses twice weekly, coupled with vigorous attempts at avoidance of allergens, dirty air, etc. More advanced cases may actually require the withdrawal of contact lens wear for several weeks to months, with the possibility that reintroduction of lens wear might be successful with a different lens type. The use of medication is generally not required or even appropriate in this condition with the exception, sometimes, of the use of topical mast cells stabilizing agents (Patanol or Elestat) in situations where lens change, aggressive lens hygiene, lens enzyming twice weekly, allergen avoidance, and limiting total number of hours of lenses worn to 50 hours or less each week has been associated with substantial improvement of the symptoms of the disorder, but mild residual symptoms persist.

Vernal keratoconjunctivitis is an unusual, complex disorder involving not just simple, classic allergic responses, but a more complex immunologic/inflammatory process. This disease has major potential for damage to the cornea and loss of vision. The disease affects young people, much more often than older people, is considerably more common in males than in females, and generally occurs in the Spring in temperate climates and is much more common in warmer climates than in temperate or cold climates. It is particularly prevalent in the Middle East. It is characterized by the development of very large bumps on the lining of the upper eyelid. Itching is a prominent symptom. Other symptoms and signs include ocular burning, foreign body sensation, excessive tearing, excess mucus production, and blurred vision. This is not a trivial disease. Parents of patients with this disease should not be lulled into a false sense of security that "junior will outgrow this;" indeed, the patient probably will outgrow the condition, but if mistreated or untreated he may well end up with permanent damage to the cornea by the time he outgrows the disease. This disease requires careful involvement of an ophthalmologist, and patient care and treatment almost always involves the use of a topical mast cell stabilizing agent. Topical steroids may be required, briefly, during periods of major attack of the signs and symptoms of the disease.

Atopic keratoconjunctivitis is also a serious allergic eye disease with major blinding potential. It typically occurs in young adults and adults with atopic dermatitis (eczema). Ocular itch is the primary beginning symptom but foreign body sensation, ocular burning, excessive tearing, mucus production, and blurred vision generally eventually occur. The key to long-term success in controlling this condition is close control of the systemic allergic problem, the atopic dermatitis. A dermatologist, allergist, and ophthalmologist, probably need to participate collaboratively in the care of patients with atopic keratoconjunctivitis. Environmental controls represent the most importance component to the care of individuals with this problem. Systemic antihistamine therapy, topical mast cell stabilizing therapy, episodic topical antihistamine therapy, and brief topical steroid therapy may all have their place in the care of patients with this extremely complex, potentially devastating disorder. Some patients may even require the systemic immunosuppressive agent, cyclosporin, to stop the progressive deterioration in the eyes produced by the inflammation secondary to this disorder.

In summary, allergic eye disease is far from trivial. It is extremely common, epidemiologically and economically important, and some forms are potentially blinding. The more serious forms of allergic eye disease are generally not curable, but like high blood pressure or diabetes, they are imminently treatable. Such treatment is often life-long. Patients with these diseases would be well advised to take the problem seriously and make a life long commitment to keeping the problem under control.