A contact lens designed for visual correction has been shown to deliver antihistamine to treat allergy as effectively as directly administering a topical drug, according to a study published in Cornea.
Researchers say this suggests the lens/antihistamine combination can provide a means of simultaneous vision correction and treatment for CL wearers with ocular allergies, who usually need to remove their lenses to treat itching eyes.
The contact lens-based drug delivery system for therapeutic delivery of the antihistamine ketotifen was tested in two parallel, conjunctival allergen challenge-based trials. Both trials employed the same multicenter, randomised, placebo-controlled protocol. Test lenses were etafilcon A with 0.019 mg ketotifen; control lenses were etafilcon A with no added drug.
Subjects were randomised into three treatment groups. Group 1 received a test lens in one eye and control lens in the contralateral eye; the eye chosen to receive the test lens was randomly selected in a 1:1 ratio. Group 2 received test lenses bilaterally, and group 3 received control lenses bilaterally.
Allergen challenges were conducted 15 minutes after lens insertion (to test onset) and 12 hours after insertion (to test duration).
