New Paradigms in the Treatment of Ocular Allergies

November 10, 2006

New Paradigms

Ophthalmologists in practices and clinics across the United States are seeing more patients with ocular allergies: a trend which may be due to higher levels of pollutants and changing lifestyles that reduce early exposure to allergens. To counter the increasing prevalence of ocular allergies, physicians can turn to new methods for differential diagnosis, new treatment options, and new individualized management strategies.

In a breakfast symposium at the Venetian Hotel, Terrence P. O'Brien, MD, moderated a panel discussion and reminded the audience that approximately 50 million Americans, or 25% of the population, suffer from allergic rhino-conjunctivitis. Whether they see a general practitioner, allergy specialist, or ophthalmologist, they want the same thing, Dr. O'Brien said.

"The majority of patients want an eye drop that is fast-acting, has a favorable adverse reaction profile, and is not habit-forming; most importantly, they want long-lasting relief of both their symptoms and their signs," said Dr. O'Brien, professor of ophthalmology, Charlotte Breyer Rodgers distinguished chair in ophthalmology, and director of the refractive surgery service at Bascom Palmer Eye Institute of the Palm Beaches, Palm Beach, FL.

Multiaction therapies, combining a mast cell stabilizer and an antihistamine, are becoming the agents of choice in treating ocular allergies, and a new product is expected to offer patients more of what they want, Dr. O'Brien said.

The agent is a new formulation of olopatadine hydrochloride ophthalmic solution 0.1% (Pataday, Alcon Laboratories) that is taken once rather than twice daily. The once-daily formulation is a 0.2% concentration, which will lead to enhanced efficacy and improve patients' quality of life through less frequent dosing, said Francis S. Mah, MD, assistant professor of ophthalmology, cornea, external disease, and refractive surgery service, University of Pittsburgh School of Medicine.

Once-daily dosing also may improve patient compliance and satisfaction, Dr. Mah said.

In treating pediatric patients with ocular allergies, factors such as dosing frequency, comfort, compliance, and safety are important considerations, and the new formulation of olopatadine could be helpful in this population, said Terry Kim, MD, associate professor of ophthalmology, Duke University School of Medicine, Durham, NC.

Dr. Kim estimated that ocular allergies affect up to 40% of the pediatric population and may be caused by environmental factors or have a genetic basis. Chronic eye rubbing is common in children with ocular allergies and can lead to adverse consequences, including corneal complications such as keratoconus. Therefore, children and their parents should be taught and reminded often to avoid rubbing their eyes, Dr. Kim said.

A sizeable proportion of the adult population also suffers from ocular allergies, and it is important to discern whether they have any concomitant conditions, such as dry eye or blepharitis. If so, all of the conditions must be treated or the allergy therapy will fail, said Michael B. Raizman, MD, associate professor of ophthalmology, Tufts University School of Medicine, Boston.

Dr. Raizman also emphasized that a thorough patient history is vital, explaining that signs of ocular allergy such as redness or chemosis can be transitory and may not be prominent when a patient is examined under a slit lamp in a climate-controlled office.

You have to listen to their story and ask them about their symptoms and what they've been experiencing to make the diagnosis, he said.

A history of ocular allergies is also important to ascertain in patients planning to undergo refractive surgery procedures such as LASIK or PRK. According to Deepinder K. Dhaliwal, MD, associate professor of ophthalmology, University of Pittsburgh School of Medicine, 20% to 30% of refractive surgery patients have associated allergy. This can contribute to contact lens intolerance, and use of oral antihistamines can cause ocular dryness, Dr. Dhaliwal said.

More importantly, there can be implications in refractive outcome,she added. We need optimal healing for optimal visual outcome after refractive surgery.Diffuse lamellar keratitis (DLK) was firmly linked to allergies in a landmark 2003 study, which found that atopy is a patient-specific risk factor for the development of DLK after primary bilateral LASIK. The study also found that atopic individuals benefit from preoperative treatment to minimize the incidence of DLK and the potential for vision loss, Dr. Dhaliwal said.

Studies have also shown that allergic conjunctivitis is a risk factor for regression and haze after PRK. The evidence thus shows that treatment of ocular allergy will help improve the outcomes of refractive surgery and that second-generation antihistamines are the class of choice for optimal preoperative treatment, she added.

The program was jointly sponsored by the New York Eye and Ear Infirmary, which received a financial benefit from Alcon Laboratories, and CME2, an independent subsidiary of Advanstar Communications, publisher of Ophthalmology Times.

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