Physicians agree on aggressive allergy treatment

Find out in our Spotlight on Ocular Allergy how to effectively diagnose and treat the forms of allergic conjunctivitis that you may encounter this allergy season.

Issue: April 1, 2002

It is estimated that 20% of Americans suffer from allergic conjunctivitis, yet only a fraction of these people receive proper treatment. Are you properly managing your allergy patients?

In this issue, Ocular Surgery News presents an overview of the proper diagnosis and treatment of ocular allergies. Through a combination of original articles and news reports from recent meetings, the clinician can find out what steps physicians are taking to ensure that every allergy patient is treated properly and learn how to incorporate new and effective medications into his or her allergy regimen.

Know your allergies

According to Peter A. D’Arienzo, MD, and Andrew Ober, MD, there is currently an underdiagnosis of allergic conjunctivitis and mismanagement of its treatment in the United States. Drs. D’Arienzo and Ober cite that only a small percentage of people who suffer from allergy symptoms are benefiting from appropriate therapy. By asking the right questions about a patient’s history and current condition, ophthalmologists can accurately diagnose ocular allergy. They can then prescribe the necessary treatments, including topical, nasal and systemic drugs.

According to their report, quality-of-life surveys have found that allergic problems are more debilitating to patients, both medically and psychologically, then many other chronic diseases. Therefore, there is a need for educated patients and physicians. In their report, Drs. D’Arienzo and Ober discuss the differences among the types of current medications available, including antihistamines, vasoconstrictors, mast-cell stabilizers, dual-action drugs and steroids. They also explain the differences between allergic reactions that take place in the eye and those that affect other parts of the body.

Multimodality drug

New multimodality drugs can provide the efficacy of mast-cell stabilization and histamine blockade together to combat allergy, according to Stefan D. Trocme, MD. In his research, Dr. Trocme found a majority of his patients reported satisfaction and improved quality of life after treatment with a combination of a dual-action drug, such as Alocril (nedocromil sodium, Allergan), with a “soft” steroid.

According to Dr. Trocme, in a presentation given at the Hawaii 2002 meeting, nedocromil inhibits the release of mast cells mediators while blocking histamine in the conjunctiva. He recommends combining nedocromil with soft steroids, which achieve the therapeutic effects of regular steroids without the harmful side effects that steroids can cause. The soft steroids that he prescribes in his daily practice are Alrex (0.2% of loteprednol etabonate) and Lotemax (0.5% of loteprednol etabonate). Both of these drugs are from Bausch & Lomb.

Dr. Trocme recommends a short course of these agents for patients with serious conjunctivitis, concurrently with a longer course of nedocromil.

Pathology in vernal conjunctivitis

An overabundance of the enzyme gelatinase B was found in patients with vernal keratoconjunctivitis (VKC) in a study by Ahmed M. Abu El-Asrar, MD, PhD. This suggests that gelatinase B may be involved in the pathology of VKC.

Researchers speculate that, in patients who have VKC, eosinophils are triggered to release an excess of gelatinase B. In patients with a normal conjunctiva, there were normal levels of gelatinase B found. According to Dr. Abu El-Asrar, whose study was published in Archives of Ophthalmology, the exact cause of the release is unknown.

Further examination is needed to determine what factors inhibit the release of gelatinase B in eosinophils, causing the breakdown of conjunctiva in patients with VKC. Dr. Abu El-Asrar and colleagues believe that this mechanism of action should be investigated for future therapeutic treatment of VKC. By controlling the release of gelatinase B, researchers may find a future treatment for patients with the condition.

Be informed

The need for educated physicians and patients is echoed by David B. Granet, MD. At the Ocular Drug and Surgical Therapy Update meeting, Dr. Granet stressed the importance of knowing how to identify and appropriately treat conjunctivitis. According to Dr. Granet, allergic conjunctivitis can look like other eye conditions such as blepharitis and infection. Because allergy can be masked as a number of eye disorders, it is often misdiagnosed in children by pediatricians and in adults by primary care physicians.

Dr. Granet said it is the ophthalmologist’s duty to recognize these differences through careful analysis and treat patients appropriately. He encourages physicians to conduct a routine eye exam on patients suspected of allergy. He also recommends that the physicians take a history of the patient’s eye conditions and symptoms.

Management can include avoidance of environmental allergens such as pet dander and grass pollen and taking a combination of mast stabilizers and histamine blockers, he said.

Mast-cell stabilizer

Success with another dual-action drug was described in another presentation at Hawaii 2002. According to Bob Lanier, MD, Patanol (olopatadine hydrochloride, Alcon) was found to effectively inhibit all mast cells forms in the eye. In his research, Dr. Lanier examined the effect of olopatadine, a mast cell stabilizer and histamine blocker. He found that olopatadine inhibited the infiltration of calcium, affected membrane fluidity and inhibited phosphorylation of several key proteins that trigger allergic symptoms.

This research is significant because olopatadine acted on both types of mast cells in the eye — those predominated by tryptase and kinase, and those predominated by tryptase alone.