A forced choice comfort study of olopatadine hydrochloride 0.1% versus ketotifen fumarate 0.05%

Purpose: To compare the ocular comfort of two ophthalmic anti-allergic agen ts: olopatadine hydrochloride 0.1% and ketotifen fumarate 0.05%. Subjects and Methods: In a double-masked, multi-centered, randomized trial, 80 subjects were asked to make a 'forced choice' based on ocular comfort b etween one drop of olopatadine hydrochloride 0.1% instilled in one eye and one drop of ketotifen fumarate 0.05% instilled in the contralateral eye. At one site, the incidence of adverse reactions was also reported. Results: All subjects (100%) selected olopatadine as the more comfortable f ormulation. One site (n=35) reported a 49% incidence of moderate burning an d a 49% incidence of mild burning after ketotifen instillation. One subject (2% of population) at this site experienced no ocular discomfort with keto tifen, There were no reports of discomfort associated with olopatadine inst illation. Conclusion: Olopatadine is a more comfortable ophthalmic preparation than k etotifen.