"Epinastine is a potent antihistamine and offers mast cell stabilizing and anti-inflammatory activities so that it provides rapid relief of existing symptoms and continued control," said Dr. Barber, professor of ophthalmology, Jones Eye Institute, College of Medicine, University of Arkansas for Medical Sciences, Little Rock.
"In addition, the formulation is soothing on instillation, which helps to establish compliance," she said. "There is in vitro evidence that epinastine causes less inhibition of the muscarinic-3 receptor than other products for treating ocular allergy so it should be less likely to interfere with tear secretion."
The case of a 55-year-old woman who presented in early March with recent worsening of her dry eye symptoms demonstrates a scenario in which epinastine may be an ideal treatment choice, according to Dr. Barber.
The patient reported having been told she has dry eyes for which she had been using preservative-free artificial tears on a routine basis. Her current complaints included increased burning, itching, redness, and lid swelling. Her examination confirmed ocular surface staining, but also demonstrated conjunctival chemosis along with lid erythema and edema indicative of allergic conjunctivitis.
"Since the patient was using non-preserved artificial tears, it was possible to rule out a preservative-induced reaction," Dr. Barber said. "Further questioning [revealed] she [had] experienced a similar course beginning in March of previous years."
After instilling a drop of epinastine into each eye, the patient experienced rapid relief of her burning and itching symptoms.
"Although there are many effective topical multimodal anti-allergy products for managing seasonal allergic conjunctivitis, epinastine has a particular niche for the patient with co-existing dry eye," she said. "Furthermore, because it is formulated at a pH of [about] 7, it is soothing and doesn't sting on instillation.
"The tolerability and rapid efficacy experienced by patients who receive an initial drop while sitting in the [exam] chair . . . are strong motivating factors for [patients] to fill their prescription and use the medication after they leave the office," she added.
Although epinastine is indicated for the prevention of ocular itching associated with allergic conjunctivitis, clinical experience shows the treatment also has benefits for relieving the associated swelling and redness, she added. This activity has an important positive effect on quality of life for patients with ocular allergy.
"Ocular allergy does not just cause bothersome itching and burning," she said. "It can affect [the] daily life functioning of patients who feel uncomfortable about appearing in public or going to work because of their appearance."
Because ocular allergy and dry eye disease are two of the leading diagnoses that bring patients to eye-care practitioners' offices, concomitant presence of these two conditions is relatively common, according to Dr. Barber.
The possibility of dry eye, however, may be overlooked in a patient who presents with the hallmark signs and symptoms of allergic conjunctivitis during allergy season, she said. And patients known to have dry eye may not receive proper diagnosis and treatment for their allergies if their complaints of bothersome symptoms are assumed to be dry eye-related, she added.
Maintaining an index of suspicion for concomitant disease and careful history and examination are essential to establish an accurate diagnosis and provide effective management.
"Ocular symptoms of allergic conjunctivitis generally are limited to itching and burning, whereas the range of symptoms associated with dry eye is greater and can include blurry vision, pain, foreign body sensation, and a gritty, sandy feeling," she said.
Seasonal worsening is helpful in suggesting the diagnosis of ocular allergy, as are the findings of swollen, red lids, and conjunctival chemosis, according to Dr. Barber.
"Ocular surface staining with vital dyes is needed to determine if there is concomitant dry eye disease," she added.
Dr. Barber has been on the Inspire speaker's bureau prior to 2008. She has been a principal investigator in monitored, multicenter clinical research studies for dry eye disease and blepharitis.