HealthDay)—A contact lens (CL)-based drug delivery system is effective for therapeutic delivery of the antihistamine ketotifen, according to a study published online March 19 in Cornea

 by Medical Press

Brian Pall, O.D., from Johnson & Johnson Vision in Jacksonville, Florida, and colleagues tested a CL-based drug delivery system for therapeutic delivery of the antihistamine ketotifen in two parallel, conjunctival allergen challenge-based trials. Lenses were etafilcon A with 0.019 mg ketotifen (test lenses) or no added drug (control lenses). Group 1 received a test lens in one eye and control lens in the contralateral eye, group 2 received test lenses bilaterally, and group 3 received control lenses bilaterally. On two separate visits, allergen challenges were conducted; participants were challenged at 15 minutes and 12 hours following lens insertion.

The researchers found that the eyes wearing the test lenses had lower mean itching scores versus the control lenses, indicating an effective reduction in allergic responses. For both trials, the mean differences in itching were statistically and clinically significant at both time points.

"Over the last decade, there has been considerable interest in extending the function of the CL beyond that of vision correction alone," the authors write. "Collectively, these results support the use of lenses with ketotifen for the prevention of ocular itching associated with allergic conjunctivitis in patients who use CLs for vision correction."

Several authors disclosed financial ties to ophthalmic companies, including Johnson & Johnson Vision, which funded the study.