The US Food and Drug Administration has approved a new contact lens that elutes the antihistamine ketotifen as a treatment for ocular allergy.
"This is the world's first and only contact lens that's able to prevent itching associated with allergies, while at the same time providing vision correction," said Brian Pall, DO, director of clinical science at Johnson & Johnson Vision Care, which is making the lens. "It's certainly exciting."
The new lens, Acuvue Theravision With Ketotifen, is already on the market in Canada and Japan.
The lenses are daily disposable contacts indicated for the prevention of ocular itch due to allergic conjunctivitis in people who do not have red eyes, are suitable for wearing contact lenses, and do not have more than 1.00 D of astigmatism.
Antihistamine eyedrops are contraindicated for use with contact lenses because eyedrop preservatives could interact with the lenses, and clinical trials generally exclude contact lens wearers.
Johnson & Johnson worked for over a decade to find an antihistamine that paired well with a contact lens material, finally hitting on the combination of ketotifen and etafilcon A, said Pall. The drug is integrated into the polymer during manufacturing.
In contact with the eye, the drug diffuses from the lens into the tear film and is absorbed by the ocular tissues, much like a conventional eyedrop. "The key difference is that this is a slower release," Pall said. "Instead of a bolus of this large drop hitting the eye and then being flushed out immediately, we get a much more sustained release."
Because the lens is kept sterilized until use, no preservatives are added to the medication. This is an advantage because preservatives cause irritation in some patients.
Ketotifen, a well-established treatment for ocular allergies, not only blocks histamine receptors but also stabilizes mast cells so that they don't release cytokines, and it prevents inflammatory cells from rushing to the site of irritation, Pall said.
For a pair of identical clinical trials, published in 2019 in Cornea , Pall and his colleagues recruited 244 people with ocular allergies. For each trial, they divided these subjects into three groups. One group wore the ketotifen lenses in one eye and lenses without the drug in the other eye. The second group wore the ketotifen lenses in both eyes. The third wore the control lenses in both eyes.
The researchers then exposed the subjects to allergens and asked them to rate the itchiness of their eyes on a scale of 0–4 after 3 minutes, 5 minutes, and 7 minutes. Over these periods, the patients rated itchiness of the eyes with the ketotifen contact lenses a mean from .42–.59; they rated the eyes with the control contacts 1.60–1.94. The differences were statistically significant (P < .001).
While about 5% of patients experienced adverse events, most of the events were not judged to be related to the contact lenses. The most common adverse event, reported by about 1% of patients, was installation site irritation. "The good news, what we're hearing from the field, is it's very subtle, it's pretty mild, and it quickly dissipates," said Pall.
The new contact lens "is promising for those who have contact lenses and the 20% to 40% of the American population who have allergies," said Leonard Bielory, MD, a professor of medicine, allergy, immunology, and ophthalmology at Hackensack Meridian School of Medicine in Nutley, New Jersey, who was not involved in the trial or in developing the lens.
"I have patients who wear contacts and have allergies, and they have to work around it," he told Medscape Medical News. "I expected this 15 years ago, because this is a good idea."
Johnson & Johnson is researching other drugs that might be delivered through contact lenses, Pall said.
The study was funded by Johnson and Johnson. Pall is an employee of Johnson & Johnson. Bielory reports no relevant financial relationships.
Laird Harrison writes about science, health, and culture. His work has appeared in magazines, newspapers, on public radio, and on websites. He is at work on a novel about alternate realities in physics. Harrison teaches writing at the Writers Grotto. Visit him at lairdharrison.com or follow him on Twitter: @LairdH.
Lead Image: Johnson & Johnson Vision Care, Inc
Cite this: Laird Harrison. New Contact Lens Elutes Antihistamine for Ocular Allergy - Medscape - Mar 11, 2022.